I've read a lot here about cleaning the EGR tubes in regards to symptoms with rough idle and the car almost shutting off when slowing down. I have a '93 Sedan Deville and I wanted to know: Do I have these EGR tubes? I see one tube connected to the EGR valve, but the mechanic told me that was a vacuum line. If my '93 has EGR tubes, where are they?

If you have a 4.9 you have the "EGR tubes"....

Take the air cleaner off, hold the throttle blades wide open (engine off) and look down the throttle bores. The tubes that are sticking up at you down below the blades are the EGR tubes. They are not supposed to be full of carbon and crud...rod them out thoroughly with a piece of still wire all the way thru to the passage in the manifold below.

The EGR tubes will likely not cure any idle problems, however.

While you are in there, spray the throttle bores and the throttle blades with carb cleaner and scrub with an old toothbrush to clean the throttle bores down below the blades and the backside of the throttle blades thoroughly. The deposits that build up will restrict air flow past the blades at idle and cuase idle speed control problems. After cleaning all the deposits off of the bores and the blades and putting everything back together, disconnect the negative battery cable for 60 seconds to reset the idle learn offset values in the PCM to the default "clean throttle body" values.

Thanks for the help and location pointers. I had the throttle body cleaned on Friday with "Run Rite" fuel system cleaner. I looked at the throttle body today and the butterfly valves look good (no black crud or build up). Today, I asked my mechanic to replace my fuel filter since they didn't when the did the run rite treatment. Now they are about to install a new EGR valve. I might try to clean the EGR tubes once I get the car back. Can I use a wire hangar? If not what kind of wire will fit these tubes?

Thanks for the help and location pointers. I had the throttle body cleaned on Friday with "Run Rite" fuel system cleaner. I looked at the throttle body today and the butterfly valves look good (no black crud or build up). Today, I asked my mechanic to replace my fuel filter since they didn't when the did the run rite treatment. Now they are about to install a new EGR valve. I might try to clean the EGR tubes once I get the car back. Can I use a wire hangar? If not what kind of wire will fit these tubes?


Likely you just need to clean the EGR tubes out....not replace the EGR valve.

The tubes are fairly large in diameter. You just need to use any sort of stiff piece of wire to clean the carbon out. When you look at them you will see.

Can I use a wire hangar? If not what kind of wire will fit these tubes?

Get a gun barrel cleaning kit.
One that comes with different diameter brushes and an extension handle to attach them to.
I purchased one a while back and 2 of the brushes were a perfect fit.

You guys are great!:thumbsup: Thanks for all the help. I haven't gotten the car back yet, but I should have it tomorrow. There was a delay in getting the new EGR part. I know you said I probably didn't need it, but after my emissions failures (prior and during the rough idle) I feel that it can't hurt. I failed for NOx if you're curious. Passing was 800 or less, I was at 1100-1300 during 3 different tests. I read a lot on NOx failures, and the EGR valve was in question. So this new one won't hurt me (except for the $70 cost and labor to put it in :banghead: ). Once I get my car back I will drive it for awile WITHOUT cleaning the EGR tubes just to see if we have any improvement with the work that was done. I will then update this post with my results to help out someone else. Thanks again and stay tuned.

You guys are great!:thumbsup: Thanks for all the help. I haven't gotten the car back yet, but I should have it tomorrow. There was a delay in getting the new EGR part. I know you said I probably didn't need it, but after my emissions failures (prior and during the rough idle) I feel that it can't hurt. I failed for NOx if you're curious. Passing was 800 or less, I was at 1100-1300 during 3 different tests. I read a lot on NOx failures, and the EGR valve was in question. So this new one won't hurt me (except for the $70 cost and labor to put it in :banghead: ). Once I get my car back I will drive it for awile WITHOUT cleaning the EGR tubes just to see if we have any improvement with the work that was done. I will then update this post with my results to help out someone else. Thanks again and stay tuned.

Why create more problems for yourself? You received instructions from a GM engineer and you choose to disregard them? Maybe I missed something?

Why create more problems for yourself? You received instructions from a GM engineer and you choose to disregard them? Maybe I missed something?

Not "disregarding" suggestions/advice. I am just trying to ISOLATE the problem. I was already failing emissions tests (high NOx) so replacing the EGR Valve was next anyway. Rather than replace the EGR, have my fuel filter changed AND clean out the EGR tubes, I felt I would like to test the car BEFORE cleaning out the EGR tubes......just to see what results I would get.

New update 2/25/05. The car has the "rough idle" and "engine stumble" again. I have narrowed it down to: It only happens when the heater or defroster is on. It seems as if when the fan for the heater is blowing, the engine starts having trouble idling smooth. Anyone ever heard of this? :hmm:

Sounds like low voltage? The heater motor may have enough load to pull the volts down to a level the engine doesnt like. Do turning all the lights on make it worse also? What are the voltage readings with everything off as opposed to everything on?

BTW I like your method of doing one thing at a time and documenting the results. Scientific Method..

Thanks. There is a method to my madness. I like to specifically identify a problem if I can. Thank years of electronic troubleshooting for this habit. Anyway, I will have to check into the voltages and report back. I will post the info as soon as I get it. As far as checking the voltage, are you suggestion checking it right on the battery or at another location? Thanks.

I would check at the main fuse block.

Am now confused to this one
Thanks. There is a method to my madness. I like to specifically identify a problem if I can. Thank years of electronic troubleshooting for this habit. Anyway, I will have to check into the voltages and report back. I will post the info as soon as I get it. As far as checking the voltage, are you suggestion checking it right on the battery or at another location? Thanks.

Years of electronic trouble shooting ?
What kind of madness method are you describing ??
Do you mean replace it and if it doesnt fix it then replace something else ???

Checking the votage as CharBroiled stated and having years of experience trouble shooting elec should in my mind be self explanitory
Not "disregarding" suggestions/advice. I am just trying to ISOLATE the problem. I was already failing emissions tests (high NOx) so replacing the EGR Valve was next anyway. Rather than replace the EGR, have my fuel filter changed AND clean out the EGR tubes, I felt I would like to test the car BEFORE cleaning out the EGR tubes......just to see what results I would get..

I would have to say you did disregard the suggestions/advice."...so replacing the EGR Valve was next anyway.". Dont know why you would say it was next ? Replace ? For what reason ?
Likely you just need to clean the EGR tubes out....not replace the EGR valve.

Sounds like you have it backwards.
Replacing items does not "specifically identify a problem".

I can understand what you meant when saying you felt it couldnt hurt.
But besides the price of the part..the labour that is charged as well...what was that ?
50 maybe 60 bucks that resuted in nothing ???

According to your logic and method to madness:
If I sit down on the couch, grab the remote, hit the power button, TV doesnt come on ??
Should I change the batteries in the remote or should I open up the TV and start replacing circuit boards ?

Of course change the batteries !
But if that doesnt work then it must be the TV ?
Right ??
No matter what anyone else says. "Need A New Remote".
Hang on Im going to change this circuit board first..............

Good thing you replaced the EGR Valve though.

BTW:
Did you...... clean the EGR tubes out......

You can change as many EGR valves as you want.
But if the tubes are still plugged.................. :histeric:

Not saying that you should take what you read here or anywhere else as written in stone, (As bbobynski has personally informed me of. BTW Thanx boss).
But the info here is free.
Informative.
Educational.

Sorry for the rambling...
What was your problem again :confused:

Murphy G.....Thanks for your HELP.

Murphy G.....Thanks for your HELP.

Did you or did you not resolve the problem?
Have you had the vehicle retested for emissions yet?

Murphy G.....Thanks for your HELP.
What is the date to-day anyways :drinker
Dont thank me man.
Although I do appreciate it :thumbsup: It wasnt me that gave you any actuall info.

Feed Back Is Always Nice Though :banana:
Did you or did you not resolve the problem?
Have you had the vehicle retested for emissions yet?
EH :)

1993 Sedan Deville 4.9 V-8---Well it's been a few weeks since I've updated, so here goes. I haven't cleaned out the EGR tubes, but I should get a chance today (Rained yesterday). The car "supposedly" passed emissions but I don't have the printout from the shop. I picked the car up and it had a new inspection sticker and I had a new bill for repair/inspection. The EGR valve replacement didn't fix the "almost stalling" problems though. Symptoms: When the car is cold, and I step on the gas pedal the car starts to "choke, cough, backfire." It doesn't accelerate. After the car is warm (10 minutes or so), it seems to react to the gas pedal as it should, but occasionally at a stop sign it will have a rough idle (off and on). Work Done: I have had the run rite treatment done, throttle area is clean, fuel filter is new, oil changed, air filter, new tranny installed in Dec '04. Items not done recently: Spark Plugs, Cap, Wires, EGR Tubes Cleaned, Engine Coolant.
Help! Help! Help! I am about to scream. :banghead: This car has 175k miles on it, and has always ran like a champ, It sat for 2 years (2002-2004) and then was put back on the road at the end of 2004. It's still driveable, but it's not fun driving a car that act's up, hesitates, won't accelerate etc. I am trying of course to save a few bucks by getting some answers in this forum. Thanks.

1993 Sedan Deville 4.9 V-8---Well it's been a few weeks since I've updated, so here goes. I haven't cleaned out the EGR tubes, but I should get a chance today (Rained yesterday). The car "supposedly" passed emissions but I don't have the printout from the shop. I picked the car up and it had a new inspection sticker and I had a new bill for repair/inspection. The EGR valve replacement didn't fix the "almost stalling" problems though. Symptoms: When the car is cold, and I step on the gas pedal the car starts to "choke, cough, backfire." It doesn't accelerate. After the car is warm (10 minutes or so), it seems to react to the gas pedal as it should, but occasionally at a stop sign it will have a rough idle (off and on). Work Done: I have had the run rite treatment done, throttle area is clean, fuel filter is new, oil changed, air filter, new tranny installed in Dec '04. Items not done recently: Spark Plugs, Cap, Wires, EGR Tubes Cleaned, Engine Coolant.
Help! Help! Help! I am about to scream. :banghead: This car has 175k miles on it, and has always ran like a champ, It sat for 2 years (2002-2004) and then was put back on the road at the end of 2004. It's still driveable, but it's not fun driving a car that act's up, hesitates, won't accelerate etc. I am trying of course to save a few bucks by getting some answers in this forum. Thanks.OK, it's gonna be alright now. Step back, take a deep breath and let it out slowly. Better? Good. Now just take it one step at a time and finish the list you have posted here above. Plugs, wires, does this model still have a distributer? If so, check, clean/change the cap and rotor. Carefully check all your ignition wires and connections. Be sure to do a good cleaning on the throttle body when you clean the egr tubes and disconnect the neg. bat term for 1 minute for idle re-learn. The coolant or cooling system should not affect the way the engine runs unless it is in very poor condition, though it is vitally important to keep it in tip top shape if you want the engine to last as long as possible. Be sure to use the GM coolant pellets or the Bars Leak Gold after you've flushed the system. Use at least 50/50 antifreeze mix.
Good luck to you, keep up the fight, I'm sure you will win in the end! :thumbsup:

Actually, rechecking this thread I see that Bbob was the first to respond. He is arguably the best resource for technical advice on this forum, yet you have not acted on his suggestion. Maybe you are not aware of his knowlege and experience, if so, that is certainly forgivable. You may find that cleaning the egr tubes as he prescribed is the sum answer to your problems and subsequent frustrations. Give that a go first before you do anything else and let us know the outcome.

Well Thanks Kev. :thumbsup: Yeah, at 1st I didn't know that "Bbob" was the Master but after viewing around the forums, I see he is a great resource. Thanks "Bbob.":worship: I didn't mean to ignore your suggestion about cleaning the EGR tubes, I just haven't had the opportunity over the past 3 weeks. (I am on the road alot....Field Service Tech). My wife drives the Caddy, I drive a '98 Mustang GT Vert. Anyway, I still love the Caddy, and am trying to restore it to the way it USED to run when I bought it in 1995. It had power, ran smooth and quiet and was an overall great car. It still is, I am just behind on some repairs, and it needs new paint now. I want to try it tonight (EGR tube clean) but I might not have enough time with other things going on. We'll see. Thanks again. Oh yeah....have to ask: What size bolts are in my path to access the EGR tubes? Asking just in case I need to stop and get the right size sockets etc.? I have a standard set but no metrics.

Well Thanks Kev. :thumbsup: Yeah, at 1st I didn't know that "Bbob" was the Master but after viewing around the forums, I see he is a great resource. Thanks "Bbob.":worship: I didn't mean to ignore your suggestion about cleaning the EGR tubes, I just haven't had the opportunity over the past 3 weeks. (I am on the road alot....Field Service Tech). My wife drives the Caddy, I drive a '98 Mustang GT Vert. Anyway, I still love the Caddy, and am trying to restore it to the way it USED to run when I bought it in 1995. It had power, ran smooth and quiet and was an overall great car. It still is, I am just behind on some repairs, and it needs new paint now. I want to try it tonight (EGR tube clean) but I might not have enough time with other things going on. We'll see. Thanks again. Oh yeah....have to ask: What size bolts are in my path to access the EGR tubes? Asking just in case I need to stop and get the right size sockets etc.? I have a standard set but no metrics.You will see the egr tubes when you open the throttle. Just take off the air duct and wire the throttle open. The tubes will be looking up at you from there.

"Get 'er done, Son!"

Sounds easy enough. I will do it when I get home tonight.

Well I got the EGR tubes cleaned when I got home after work. I was disappointed to find that 1 tube was completely blocked and the other one was 50% blocked! Friggin' repair shop! Of course they TOLD me that the tubes looked good, but now I think that they didn't even know what an EGR tube was. I used a hangar to clean them at 1st, then went to a long flat tip screwdriver to really scrape away the grime. I then cleaned the "butterfly" valves or whatever you call 'em with a toothbrush, rag, and some WD-40. Didn't have "carb cleaner." Disconnected the negative battery cable for a few minutes then started the car. The car definitely was "searching" for idle because of the high rpm's I noticed for a few seconds. I then let the car run for a few minutes. It seemed to "run rough" here and there while idling. I then took it for a 10 minute ride around the neighborhood. I ramped up speed and then brought the car to a stop many times. It didn't have a problem ramping down and idling. During the1st few tests when I floored it, the car hesistated while trying to burst into speed. Eventually this went away, and I had that good 'ol 4.9 acceleration response when I "punched" it. When I pressed on the brakes, the car slowed down as normal and idled when I stopped. I am going to try this test again in the morning before my wife takes the car to work. I'll post my results in the morning. Thanks to all that have offered help! Bbob.....You're the man!:)

This mornings drive? :thumbsup: Car seems to be running like a champ. Also, idles nicely at stops, and pulls off aggressively when I get on the gas pedal. Thanks to all!:D Now maybe my wife will be "nice" to me again since her car will run without problems, because previously she was letting me hear about it everyday. :madtalkin I am amazed at how that 10-15 minute job that I could do myself, would fix this problem.......thanks again guys.:2thumbs:

This mornings drive? :thumbsup: Car seems to be running like a champ. Also, idles nicely at stops, and pulls off aggressively when I get on the gas pedal. Thanks to all!:D Now maybe my wife will be "nice" to me again since her car will run without problems, because previously she was letting me hear about it everyday. :madtalkin I am amazed at how that 10-15 minute job that I could do myself, would fix this problem.......thanks again guys.:2thumbs:You are most welcome my young padawan friend. Let this be a lesson to you, always heed the advice of Master Bbob.

In the words of the inimitable Master Yogurt, "May da Shwartz be wit you."

You will see the egr tubes when you open the throttle. Just take off the air duct and wire the throttle open. The tubes will be looking up at you from there.....

:banghead: What am I missing here.
I hope someone can shed some light on my confusion.
It was always my understanding that the egr tubes were located under the egr valve. When I remove my valve, (spaceship lookin thing ? Right??), there are 2 ports/tubes there.
Thought those were the egr tubes :confused:

And when I remove my air duct and open the throttle plates, I thought that was accessing the throttle body bores. :confused:

Are these two different things that are sometimes refered to as the same thing. Or am I completely loosing it :cookoo:

Hopefully some one can confirm what "condition my condition is in". :holycrap:

Well since I just went through all of this, I can tell you. The EGR TUBES are located inside of the throttle body. If you can access your throttle body, open the blades by pushing them open or pulling the throttle cable. Hold them open, and you will see 2 tubes inside of that throttle area. This is all assuming that your engine is the same or similiar as mine (1993 Sedan DeVille). Be clear on this.....The EGR tubes ARE NOT under the EGR Valve (yes, the spaceship looking thing. :o)

This mornings drive? :thumbsup: Car seems to be running like a champ. Also, idles nicely at stops, and pulls off aggressively when I get on the gas pedal. Thanks to all!:D Now maybe my wife will be "nice" to me again since her car will run without problems, because previously she was letting me hear about it everyday. :madtalkin I am amazed at how that 10-15 minute job that I could do myself, would fix this problem.......thanks again guys.:2thumbs:

Well I spoke too soon. The problem is back. :crying2: Rough idling off and on at stops, lack of acceleration when stepping on the gas. What should I attack next? Bbob? Kev? Anyone? I am going to check the EGR tubes tomorrow to see if they are clogged again. I'd like to know if they got clogged again in 2 days. If not what's next? :helpless:

Well since I just went through all of this, I can tell you. The EGR TUBES are located inside of the throttle body. If you can access your throttle body, open the blades by pushing them open or pulling the throttle cable. Hold them open, and you will see 2 tubes inside of that throttle area.)
That is what I have done/do.
Asking... because it was my understandinding that what I was performing was a throttle body clean. From what you just said about accessing the "throttle body" and finding the egr tubes below the blades; makes me wonder what the difference is between a TB cleaning and an egr tube cleaning?
Take of the air duct, open the throttle blades, and clean it ALL.
Always thought it was one job. One service.
To think that someone would clean the TB, and then open the blades and clean the ports below, and refer to them as 2 different services sounds redundant to me.
I just assumed that it was the same service.
I assumed that that was what a throttle body cleaning consisted of.
Or how bout cleaning the blades? Just the top that can be seen?
I sure hope that no one is being charged as those it is 2, or even "3" different things.
This is all assuming that your engine is the same or similiar as mine (1993 Sedan DeVille). Be clear on this.....)
Thought it was quite clear.
When I subscribed to this forum I included in my profile what It is I drive.
It is shown every time I post. Its below my user name, but above the post I made. Kinda in-between the two. I believe our engines may be "the same or similiar".
The EGR tubes ARE NOT under the EGR Valve (yes, the spaceship looking thing. :o)
So back to my original quandry.
What then are the tubes/ports that are below the egr valve called/refered to as ? :confused:
Got an egr valve
Below that you have tubes
Hence:
I made the assumption that they were the egr tubes.

Any idea :yeah:

When you remove the EGR valve on a 4.9 there are no tubes or anything below it...just two ports or holes in the intake manifold. They are the EGR ports in the intake manifold, I guess. The EGR valve and that area on a 4.9 rarely if ever needs any service.

The EGR tubes are the two tubes sticking up below the throttle blades from the bottom of the intake manifold...you look directly down into them as you look down the throttle bores with the throttle blades held wide open...as has been described in at least 100 previous posts...LOL LOL

Cleaning the throttle body blades and bores is a maintenance item that affects the idle speed control and throttle feel off idle. Lots of times throttle bodies are cleaned and people haven't the faintest idea to clean out the EGR tubes also. THAT is why they are typically desribed and treated as two distinctly different things...because they require two distinctly different cleaning methods, doing one does not guarantee the other and they affect two completely different systems.

EGR valve cleaned, as often described on this forum, is done/required on the NORTHSTAR engine...not the 4.9.

Well I spoke too soon. The problem is back. :crying2: Rough idling off and on at stops, lack of acceleration when stepping on the gas. What should I attack next? Bbob? Kev? Anyone? I am going to check the EGR tubes tomorrow to see if they are clogged again. I'd like to know if they got clogged again in 2 days. If not what's next? :helpless:


Time to get a fuel pressure gauge and check the fuel pressure when driving and when the problem occurs. It sounds like the fuel pump may be starting to loose capacity and loose fuel pressure when demand hits it....

Sounds like the EGR tubes were plugged so they needed cleaning anyway and the throttle body needed it, too, so that wasn't a waste of time eliminating those items.

The rest will just take some more diagnosis.

This morning I checked my EGR tubes again and they are still clean from my cleaning job a couple of days ago. What I did notice was that there is a hose on the back of the air duct that was hanging loose. I probably pulled it loose when I removed the air duct to clean the tubes the other night. What I want to know is what is that tube for? Also, could this hose on the back of the air duct cause my specific problem if it was left disconnected? I re-connected it, and my wife reports no symptoms or problems with the car during her drive to work. I will monitor to see if the problem re-surfaces.

When you remove the EGR valve on a 4.9 there are no tubes or anything below it...just two ports or holes in the intake manifold. They are the EGR ports in the intake manifold, I guess. The EGR valve and that area on a 4.9 rarely if ever needs any service.

The EGR tubes are the two tubes sticking up below the throttle blades from the bottom of the intake manifold...you look directly down into them as you look down the throttle bores with the throttle blades held wide open...as has been described in at least 100 previous posts...LOL LOL

Cleaning the throttle body blades and bores is a maintenance item that affects the idle speed control and throttle feel off idle. Lots of times throttle bodies are cleaned and people haven't the faintest idea to clean out the EGR tubes also. THAT is why they are typically desribed and treated as two distinctly different things...because they require two distinctly different cleaning methods, doing one does not guarantee the other and they affect two completely different systems.

EGR valve cleaned, as often described on this forum, is done/required on the NORTHSTAR engine...not the 4.9.

Thanx bbobynski
Guess that it never quite set in that it was 2 different things. Just go in and clean it all.
I believe that someone told me that the egr tubes were under the valve. Think that was quite a while back in the old forum. So in those hundreds of posts on the subject I must have dismissed the fact that opening the blades was to clean the egr tubes. Had it set in my mind that was a part of cleaning the throttle body. No harm done I guess. Always did the job right.
Except for the pain in the ass time I had to remove the egr valve to clean what I had been told were the tubes. LOL.
And I must say...they WERE spotless.
So much for bad info and assumptions.
Thanx again bbobynski
......could this hose on the back of the air duct cause my specific problem if it was left disconnected?
I believe that it could. Left mine disconected one time and could barely start the car let alone get out of the driveway. Give it a test. Pull it off and see how it starts. Or even pull it off once its running. See if you get the same symptoms.

I need advise myself,

My car idled very smoothly more than a few months ago. slowly by slow it started to idle rough. when I first noticed it in Nov 2004 I changed the ISC, had the EGR Cleaned at the dealer {wouldnt pass emissions}, Replaced my plugs, distributor cap, rotor and coil pack in the distributor. after that didnt work it continued to get worse. I replaced my fuel filter, got some carb cleaner from Valvoline (http://www.valvoline.com/images/products/productpages/bottle_bot_054.jpg]Valvoline) cleaned out my throttle body, changed the air filter and PCV. still continued to grow worse. Now Im at a light feeling the engine shake watching my hand vibrate on the wheel and have the slightest clue of what I can do next. Im not showing any codes.

Are there any suggestions. Its not cutting off or stalling. just idles rough. It didnt idle rough in June when I got it, It happened slowly all the way up until now.:helpless: I even a few days ago cleaned my heater core and changed the fluid. no help.

Well Mr. Smith, I feel your pain. It sounds like both of our cars are doing the exact thing. Shaking at stop signs etc. I have been battling the problem for over a couple of months now. New EGR valve, fuel filter, run rite treatment, EGR tubes cleaned. I just cleaned the throttle body again today with Carb Cleaner as recommended by bbob. The 1st time I went into the throttle and cleaned the EGR tubes, I cleaned the throttle area with WD-40, a hangar, a toothbrush, and a rag. After today's carb cleaner job, I took the car a test drive. So far so good. Accelerates great, and I even "chirped" my front 2 tires when pulling off from a stop. When I floor it, the car down shifts and accelerates smooth. I liked it. After the speed runs, I slowed down to a nice NORMAL idle with no "shaking." We'll see how it act later tonight, and tomorrow. I'll update this forum. Thanks for your post, because I was about to get into replacing plugs, wires, and cap. I will hold off for now.

I wonder if O2s synsors have anything to do with it. Im not gettig any codes but I wonder.

It continues. After last nights 1st test drive, the results were good. Later that night the results were terrible. The car actually had a hard time starting and stalled on me at a couple of stops. It also was back to the "hiccups" and "hesitation" when I applied pressure to the gas pedal. I was low on gas (3 gal showing on readout), so I put gas in the tank. The car drove better after I got it started, which took 5 to 10 cranks. This morning it started on the 2nd try, but still shakes at stops, and when parked at idle.

Mr. Smith, I would think that if the O2 sensors were bad, you would get codes reflecting that. I really need a good Cadillac mechanic to give me some advice. I don't mind spending a few bucks on the repair, I just want the correct repair performed. I am trying to stay away from Cadillac's $90 per hour labor fees.

It continues. After last nights 1st test drive, the results were good. Later that night the results were terrible. The car actually had a hard time starting and stalled on me at a couple of stops. It also was back to the "hiccups" and "hesitation" when I applied pressure to the gas pedal. I was low on gas (3 gal showing on readout), so I put gas in the tank. The car drove better after I got it started, which took 5 to 10 cranks. This morning it started on the 2nd try, but still shakes at stops, and when parked at idle.

Mr. Smith, I would think that if the O2 sensors were bad, you would get codes reflecting that. I really need a good Cadillac mechanic to give me some advice. I don't mind spending a few bucks on the repair, I just want the correct repair performed. I am trying to stay away from Cadillac's $90 per hour labor fees.


No...you need to cobble up a fuel pressure gauge and check the fuel pressure. That is a pretty basic, simple test of health for a port fuel injection system. Find an old R12 refrigerant recharge kit/adapter hose at an auto parts store. The fitting for the R12 refrigerant fitting is the same as the fitting on the fuel rail for a fuel pressure gauge. Find an old 50 PSI gauge of some sort and with $2 worth of hose and brass fittings you can make a fuel pressure gauge. Screw it onto the fitting on the rail, tape it to the hood or windshield where you can see it while driving and take a ride. Watch the fuel pressure to see if it drops off or stutters when the driveability issues exist. Simple and basic check. If the fuel pressure is not up to snuff then the fuel pump is the likely culprit.

Thanks for the advice again, Bbob. Friday I took my car back to the shop that I had do the EGR replacement and they diagnosed the car with me standing there. I watched them test the fuel pressure. It had 35psi when you turned the key, and it seem to maintain around the same when running. The mechanic looked up the spec and said that the fuel pressure for the car should be at 40psi. Is this true? He didn't think that the 5psi difference would cause the symptoms but wasn't sure. They also pulled a hose (vacuum I think) off of the fuel regulator. With the hose disconnected, the car seemed to idle perfectly. When they put it back on, the car stumbled, and searched for idle. They are going to replace the fuel pump on Monday. I'll update when we get the car back. A side note, they also said that my fuel filter looked really bad when they replaced it about a month ago. One guy said it was really clogged and that could have overworked the fuel pump and damaged it. Since I have no experience.....who knows? I know a clogged artery will over work your heart, so I am thinking the same is true with a fuel pump.

I started mine when it was cold and it ran fine. I went into diagnostics and waited for the auto light to come on. When the auto light came on, indicated the computer is going in closed loop, it ran bad. I had a bad ground to the O2 Sensor. It helped dramatically. But some of the problem is still there. Share what happens with yours.

Blaze

Thanks for the advice again, Bbob. Friday I took my car back to the shop that I had do the EGR replacement and they diagnosed the car with me standing there. I watched them test the fuel pressure. It had 35psi when you turned the key, and it seem to maintain around the same when running. The mechanic looked up the spec and said that the fuel pressure for the car should be at 40psi. Is this true? He didn't think that the 5psi difference would cause the symptoms but wasn't sure. They also pulled a hose (vacuum I think) off of the fuel regulator. With the hose disconnected, the car seemed to idle perfectly. When they put it back on, the car stumbled, and searched for idle. They are going to replace the fuel pump on Monday. I'll update when we get the car back. A side note, they also said that my fuel filter looked really bad when they replaced it about a month ago. One guy said it was really clogged and that could have overworked the fuel pump and damaged it. Since I have no experience.....who knows? I know a clogged artery will over work your heart, so I am thinking the same is true with a fuel pump.

Like Bbob alluded to, fuel pressure just sitting is different from actual pressure when driving around in the vehicle. I changed the pump on my 89 deville and noticed that it had the GM filter sock that can collapse and partially clog up the works.

What I don't remember off hand, is whether it had the notorious fuel baffles in the tank (ala 90's chevy trucks) that can seperate from the tank and bend your pump mounting tube so that flow is reduced. I also would advise that you put in a new isolator to avoid having to do so in a few months (right after you fill it up of course). Also make sure that your mechanic pays special attention to the wiring harness in tank so that you aren't dropping the tank again due to corrosion at the terminals causing you problems.

More on my 1993 Deville: I got the car back tonight with a new fuel pump. My tech wasn't sure it was the fix and asked me to drive it tonight and tomorrow to check it out and let him know how it went (I haven't paid for the work yet). I did. It still sucks. It's not stalling now, but it still idles rough, and hesitates on acceleration off and on. Not as bad as last Friday, but it's still there. I pulled the codes from computer using the OFF and WARMER button. I have codes: E22, E23, E31, E52, and E70. 2 of these codes refer to the TPS sensor, one refers to the MAP sensor. Any suggestions on where I should go from here. I am dropping the car off again to the repair shop.

I think there is something unhooked. Check all the connectors by the back of the engine and by the distributor.

Blaze

Well I "Bit the bullet," I took my car to Cadillac. The visit turned out good. They replaced my altenator 1st (it tested bad), and wouldn't you know it......the freakin' car runs normal now? I was told that the altenator was making a "whining" noise (which I knew about) and that the noise was setting off the "knock" sensor that happens to be located near the altenator. This "knock" sensor information was making the computer change the air/fuel mix or something of that sort, which was the reason for my idle and acceleration problems. Wow. All of these weeks, and uneccesary work at a "local joe schmoe" repair shop, to find out if I had replaced the bad altenator (that I knew about) 1st, I would've solved the problem :bonkers: . I say I knew about the altenator because it had a "whining" sound when the engine was idling, and when you accelerated it made a louder, higher pitched sound. Months ago, a mechanic told me that it probably had bad bearings in it. Anyway, the new altenator fixed the problem for a total of $337 installed. I can't complain, I deserved it :banghead2 . I am going to take this car to Cadillac now for anything above oil, filter, tire changes and save myself the hassle. This local Caddy store is Ayres Cadillac in Burlington, NJ. http://www.ayrespontiaccadillac.com/ They are a Christian owned and operated business, and it showed! Friendly service, with a nice, quiet, peaceful service area and showroom. No loud music, no cigarette smoke, no yelling and screaming going on in the service bays. My wife and I were impressed to say the least. I was told that I should get a tune up for another $350-400, and when I priced other shops (Firestone's etc) it was the same cost. So I don't save a buck using the "knock off" shops, plus I get AC Delco parts at the Caddy Dealer. WIN WIN. I am just glad it's all over. I plan to get the tune up in a couple of weeks. I hope this post helps someone else. Thanks to all that commented and tried helping me out. The EGR clean was a definite need and it helped me learn something about my car. Same with the fuel pressure check etc. Thanks again Bbob, kev, and others.:thumbsup:

Well I "Bit the bullet," I took my car to Cadillac. The visit turned out good. They replaced my altenator 1st (it tested bad), and wouldn't you know it......the freakin' car runs normal now? I was told that the altenator was making a "whining" noise (which I knew about) and that the noise was setting off the "knock" sensor that happens to be located near the altenator. This "knock" sensor information was making the computer change the air/fuel mix or something of that sort, which was the reason for my idle and acceleration problems. Wow. All of these weeks, and uneccesary work at a "local joe schmoe" repair shop, to find out if I had replaced the bad altenator (that I knew about) 1st, I would've solved the problem :bonkers: . I say I knew about the altenator because it had a "whining" sound when the engine was idling, and when you accelerated it made a louder, higher pitched sound. Months ago, a mechanic told me that it probably had bad bearings in it. Anyway, the new altenator fixed the problem for a total of $337 installed. I can't complain, I deserved it :banghead2 . I am going to take this car to Cadillac now for anything above oil, filter, tire changes and save myself the hassle. This local Caddy store is Ayres Cadillac in Burlington, NJ. http://www.ayrespontiaccadillac.com/ They are a Christian owned and operated business, and it showed! Friendly service, with a nice, quiet, peaceful service area and showroom. No loud music, no cigarette smoke, no yelling and screaming going on in the service bays. My wife and I were impressed to say the least. I was told that I should get a tune up for another $350-400, and when I priced other shops (Firestone's etc) it was the same cost. So I don't save a buck using the "knock off" shops, plus I get AC Delco parts at the Caddy Dealer. WIN WIN. I am just glad it's all over. I plan to get the tune up in a couple of weeks. I hope this post helps someone else. Thanks to all that commented and tried helping me out. The EGR clean was a definite need and it helped me learn something about my car. Same with the fuel pressure check etc. Thanks again Bbob, kev, and others.:thumbsup:

Im glad your glad. Im glad they made a good impression on you.

I really hope it fixed the problem.:thumbsup:

..............They replaced my altenator 1st (it tested bad), and wouldn't you know it......the freakin' car runs normal now? I was told that the altenator was making a "whining" noise (which I knew about)......................
I say I knew about the altenator because it had a "whining" sound when the engine was idling, and when you accelerated it made a louder, higher pitched sound...........................
I hope this post helps someone else................................
Thanks again Bbob, kev, and others.:thumbsup:

I have to say it may help me.
So must also say Thank You.
Add your own name to your list of thanx.

My 93 isnt an STS, so no knock sensor I believe.
But the whining from the alternator that you have described is much too familiar here.
I was 87% sure that my whine was from the same. But then had a mech tell me it was the power steering pump. Didnt quite believe him. But brought my suretty down to round 70%.
To here you say that the alternator can create almost ghost like problems has helped. Im up to about 95% now.

Thanx rmonyer.
Your feed back/update back has been helpfull !

I have a 93 sedan that used to idle rough and stall occasionally and now does it more frequently. In 1989 I was an ASE certified master technician working at a Cadillac dealer. I no longer work as a wrench for a living but I did learn one thing when turning wrenches for a living: It is usually easier, cheaper and quicker to listen to someone who has been there before. The first thing I am going to do is to CLEAN MY FRIGGIN EGR TUBES and see if that takes care of it. I'll let you guys know in a few days....

Hey Danowiller, did it help? I am having the same issue I will be cleaning mine this weekend. This Post needs to be stickied

Well everyone, I experienced a short lived "happiness." The new altenator worked good, quieted my engine etc., but didn't fix the overall problem. Another day or so after my post about how great they were at Cadillac, I attempted to drive the car 80 miles to NYC. We didn't make it. The car started having problems keeping speed and seemed to be "sputtering." I pulled off of the freeway and ended up getting a catalytic converter for $590 at Midas. Didn't fix my problem though. It cured the fact that all the sputtering on the freeway ruined my original cat, and it added to the money wasted on trying to save my '93 Deville, but that was it. The next day, I got the car almost home and the sputtering started again. It was sputtering so bad I couldn't drive 5mph! I pulled to the side of the road and looked under the car and noticed the Cat cherry red. I had to get the car towed to the local Caddy shop. Good thing I broke down 5 miles or so from my house and the dealership. After running some tests on the engine, it was determined that the car was to need a timing chain job and some other associated work. $1900 was the estimate. I would also need a new exhaust system from the Catalytic converter back. The new one got ruined (when it got cherry red). Well to shorten my story as much as possible, I traded the Cadillac in for a 2001 Dodge Stratus for my wife. I found a good deal at Dodge dealership and they gave me a little for my Caddy. It's had it's day in my book. 179,000+ miles, but I couldn't afford to keep it running. I am kind of ticked off because in 6 months or so I spent $1700 on a new tranny, $337 on a new Altenator, $590 on a new Catalytic Converter, $40 on a Map sensor, $200 on a new EGR Valve (installed), $80 on a rental car, time off of work, my wife having to get rides from work etc, etc, etc. She was more than fed up :rant2: , and if any of you are married or have a woman in your life you know that if mama ain't happy, nobody is happy! To get some peace at home (and to maybe be able to get a "piece" again ;) ) I got her another car. So long problem Caddy! :brutal:

So I will make this my last post. I had hoped I could keep the car running, and was enjoying the information from this site, but it's all over. I have had a nice couple of weeks with no car problems, and I look forward to catching up all the money I wasted. Good luck to you all with your cars.

I would replace the spark plugs. They perhaps original. I replaced mine at 140.000 they had 0.75 gap but the car ran very well. Replaced with ACDelco regulars.

Well, I was not surprised the altenator did not fix anything. Knock sensor at 4.9 ... Huhhh...BS from a Christian stealership! Excuse me. All you probably needed were anew set of wires for some $30 on ebay and 8 plugs for $16. If one or several of your cylinders did not work (even part time) you would easily kill your catalitic converter. It is amasing how easy people trust dealerships and do not want to liste to eople who shere their experience without making a dime!

Was also wondering about the knock sensor in a 93? Didnt catch where he said it was a 4.9 though. Might have missed that.

Timing, Aternator, Cat convertor, Very expensive items !!!

Would rmonyer have any grounds for some kind of recourse here ???

Whats with the cat going cherry red right after a new one was installed ????

Why is it that there is no culpability when it comes do diagnosing and repairing a vehicle ??