: Weird problem



Dadillac
05-04-13, 01:18 PM
So on Thursday morning I was heading to get mt car state inspected. It started running strange almost like it is misfiring. The car is not throwing any codes. When at a stop light the car seemed to want to go. It was lurching forward even though my foot was firmly on the brakes and the throttle was closed. This same thing happened to my '02 Seville and it was the intake plenum. So yesterday I went by the dealer and picked up a plenum. This morning I removed the intake manifold to find the plenum in good condition. No tears and seemed to snug up nicely. So I figure it might be a cracked spark plug as that has happened to this car once before. So I change out all 8 spark plugs with AC Delco 41-987's. Problem is still there. Then I decided to clean the throttle body as I had cleaner within arms reach. The problem is still there.

Since I am not getting any codes I am at a loss as to where to check next. Does anyone have any ideas? I could start throwing parts at this thing and eventually I will get it fixed. But that will be expensive. Any input is greatly appreciated

Don

Tom's Caddy
05-04-13, 02:14 PM
Power Brake Booster,maybe?:(

Dadillac
05-04-13, 03:33 PM
A little more info. I drove the car to the store and the engine got fully up to temperature. Once up to temp the problem seems to go away. That is what lead me to believe it may be a cracked spark plug. But when I pulled out the plugs none of the insulators had cracks.

Don

ral1960
05-04-13, 04:41 PM
When at a stop light the car seemed to want to go. It was lurching forward even though my foot was firmly on the brakes and the throttle was closed

That sounds like the throttle position sensor. What are your rpms at idle? What happens if you put it in neutral, foot off the gas? When the TPS went bad on my DeVille, the rpms would jump up to 2000 in neutral.

Dadillac
05-04-13, 05:55 PM
Power Brake Booster,maybe?:(
This is definitely an engine issue not a brake issue. I did check the vacuum hose for cracks and didn't feel any

Don

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That sounds like the throttle position sensor. What are your rpms at idle? What happens if you put it in neutral, foot off the gas? When the TPS went bad on my DeVille, the rpms would jump up to 2000 in neutral.
Idle stays fairly steady. If the car is in park or neutral no noticeable change in RPM but you can feel the "stumble". I just wish a code would set already so I know where to look. I think I may just throw a MAP sensor in there and see how that does. Not sure that will do anything but they are pretty cheap

Don

ral1960
05-04-13, 07:02 PM
So, what exactly is the problem? Patient presents with vague symptoms, asks for a half dozen medications.

danog
05-04-13, 10:43 PM
#PIP3146D: Rough Idle Crank No Start Extended Crank Or Misfire When Cold Due To Sticking Valves Or Excessive Carbon On Top Of The Valves - (May 11, 2011)


Subject:

Rough Idle Crank No Start Extended Crank Or Misfire When Cold Due To Sticking Valves or excessive carbon on top of the valves

http://www.cadillacforums.com/images/999999995.gif



Models:

2000-2012 All Passenger Cars with Gasoline Engines



2000-2012 All Light Duty Trucks with Gasoline Engines





This PI was superseded to update recommended field, model years and engine list. Please discard PIP3146C.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern: (http://www.cadillacforums.com/forums/#d40206e27)Rough idle, misfires, extended crank, or crank no start when cold. The engine may run rough for up to 5 minutes after starting the engine and may exhibit a P0300 DTC too. This may be caused by sticking valves or excess carbon due to fuel contamination
Note: fuel oxidation and volatility concerns can often cause these issues as well, however they cannot generally be checked in service. Trying a different, high quality fuel is sometimes the best diagnostic.

When the engine is cold, the compression on multiple cylinders may be at 0 PSI. The engine also may pop through the intake or exhaust while cranking and the spark plugs may be fuel fouled when inspected. Some engines may also experience valve damage or cam followers that are out of position as a result of this.
This condition can occur in specific areas of the country for a period of time and then it will no longer occur after the suspect fuel source has been consumed in that area of the country.
Recommendation/Instructions: (http://www.cadillacforums.com/forums/#d40206e52)If the SI Diagnosis leads to a compression loss due to sticking valves, the following information may help:
If there is no sign of valve damage or cam followers that are out of place, perform the following procedure to free up sticking valves and to prevent the valves from sticking again. If valve damage is present or if there are cam followers that are out of place, perform engine mechanical repairs as necessary to correct the concern and then perform the procedure below to prevent the valves from sticking again.

Clean the fuel system by following the applicable "Fuel System Cleaning" procedure outlined in SI.
Add fuel injector cleaner "GM Fuel System Treatment PLUS, P/N 88861011 (for U.S. ACDelco, use 88861013) (in Canada, 88861012)"... see This PI was superseded to update recommended field, model years and engine list. Please discard PIP3146C. bulletin # 05-00-89-078B, to the fuel tank in the approved quantities.
Refill the fuel tank using fuel from a high volume, high quality filling station.
Clean the induction system using GM Top Engine Cleaner. Follow the directions on the can but DO NOT force the engine to stall since forcing the engine to stall with liquid Top Engine Cleaner could cause the engine to hydro-lock. * If available use an atomizer with Top Engine Cleaner through the throttle body.
Advise the customer to change fuel filling stations. They should use fuel from only high volume, high quality filling stations or they should use a Top Tier Detergent Gasoline if available. See 04-06-04-047I (U.S.) or 05-06-04-022G (Canada) for details regarding Top Tier Detergent Gasolines.

ral1960
05-05-13, 01:41 AM
Bad gas was going to be my second guess.

What octane fuel do you use? I've tried 87, 89, and 93 in the last month and can't tell much difference, except in the price.

MoistCabbage
05-05-13, 02:05 AM
It's almost impossible to find "bad gas".

Octane is NOT the problem.

Superjim
05-05-13, 11:06 AM
http://abclocal.go.com/wls/story?id=8790677

http://chicagoist.com/2012/08/21/bp_recalls_bad_gas_from_whiting_ref.php

http://www.wtnh.com/dpp/news/business/conn-cars-being-damaged-by-bad-gasoline#.UYZ1CMqCV8E

http://autos.yahoo.com/blogs/motoramic/bp-recalls-bad-gasoline-indiana-1-200-repair-191835064.html

ral1960
05-05-13, 11:10 AM
So impossible they wrote a PIP about it, whatever that stands for. Gas will go bad if it sits for months, just ask my lawnmower. That's one reason they recommend high-volume stations.

I was asking a general question about octane. I can't detect any difference. I'm wondering if anyone else does.

Superjim
05-05-13, 11:18 AM
So impossible they wrote a PIP about it, whatever that stands for. Gas will go bad if it sits for months, just ask my lawnmower. That's one reason they recommend high-volume stations.

I was asking a general question about octane. I can't detect any difference. I'm wondering if anyone else does.

Speaking only for myself and my car... I can detect a very noticeable difference.
Both Performance and fuel mileage suffer.
My fuel mileage will drop about 10 to 12 percent when using regular vs Premium.
Performance also takes a VERY noticeable hit.

hazcaddy
05-05-13, 01:30 PM
I was asking a general question about octane. I can't detect any difference. I'm wondering if anyone else does.

Not to hijack this thread but octane ratings has been discussed in a number of threads. Short synopsis - there are two camps: one like Superjim who find a difference, and the other like me who sees none. As I'm a cheapo I stick with 87 and have never had low mileage, pinging, or lack of power.

Dadillac
05-05-13, 05:13 PM
I use 87. Always have always will. I used 93 in my Seville several years back for three tankfuls to see what the difference was. If I remember correctly I do believe that 93 octane, and a light right foot, netted me 1/2 mpg increase. So back to 87 for me. Anyway, this morning the wife and I were driving to go to breakfast, and a telling symptom happened. At a stop light, with the car misfiring which the wife felt, two messages came up. Service stability system and traction control. This same thing happened to me when I had a cracked spark plug. So now, since I changed out all of the plugs yesterday, I am thinking I have a bad coil. The same coil that was with the cracked plug (number 4) looked quite rusty. So I ordered an AC Delco coil while eating breakfast and when it gets here I will start with number 4. If that doesn't fix the issue I will change out the coils one by one until I find which one )if any of them) is the bad one. I also ordered a new MAP sensor last night so when that gets here I will change that out too. But I do believe that iy is going to be a coil

Don

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I use 87. Always have always will. I used 93 in my Seville several years back for three tankfuls to see what the difference was. If I remember correctly I do believe that 93 octane, and a light right foot, netted me 1/2 mpg increase. So back to 87 for me. Anyway, this morning the wife and I were driving to go to breakfast, and a telling symptom happened. At a stop light, with the car misfiring which the wife felt, two messages came up. Service stability system and traction control. This same thing happened to me when I had a cracked spark plug. So now, since I changed out all of the plugs yesterday, I am thinking I have a bad coil. The same coil that was with the cracked plug (number 4) looked quite rusty. So I ordered an AC Delco coil while eating breakfast and when it gets here I will start with number 4. If that doesn't fix the issue I will change out the coils one by one until I find which one (if any of them) is the bad one. I also ordered a new MAP sensor last night so when that gets here I will change that out too. But I do believe that iy is going to be a coil

Don

ral1960
05-05-13, 08:02 PM
Those aren't the messages one would expect from an engine problem.

Dadillac
05-07-13, 07:45 PM
Well the culprit for my issue may have been a bad tank of gas. But I will not know for sure until tomorrow morning. I get a call from my wife this afternoon telling me that my daughters car is broke down at college. I told her to call AAA and have it towed home I will look at it after work. So I get home and the car will run with throttle input but will not idle. I cleaned the throttle body and it wanted to run. So I cleaned it up pristine and put five gallons of fresh premium in it and it is running great now. By the way my daughter fuels up at the same station that I do. I also put a bottle of gas additive in both of our cars. I fueled up with a fresh tank of premium. So hopefully all is well now. And since I already bought the replacement coil I will be changing out the rusty one just for piece of mind.

Don

Dadillac
05-09-13, 06:28 PM
Well bad diagnosis on the bad gas. It is still doing what it is doing. But a new MAP sensor arrived today and I installed it. Just idling in the driveway it feels okay. But I will find out on the drive to work tomorrow if it remedied the issue. I will update tomorrow

Don

Dadillac
05-11-13, 03:07 PM
MAP sensor did not fix the issue. Neither did changing out the rusty coil. So now I am going to remove the intake manifold again. I am going to replace the plenum, which does seem okay, and the intake gaskets. While the intake is off I will be giving the throttle body a hospital cleaning. There is also a wire harness that runs under the intake that the wire loom is all destroyed. I will be inspecting the wires closely, repairing if needed, and relooming the harness. Hopefully one of these will repair this issue

Don

jazoo
05-11-13, 03:38 PM
A little more info. I drove the car to the store and the engine got fully up to temperature. Once up to temp the problem seems to go away. That is what lead me to believe it may be a cracked spark plug. But when I pulled out the plugs none of the insulators had cracks.

Don
I would say that it's the throttle position sensor. It happened to me once in my Buick. I was wondering how much would it cost to get the diagnostic check (with the OBD) by your local reputable auto repair shop especially when you are not getting code.

MoistCabbage
05-11-13, 03:45 PM
AutoZone will pull codes for free.

He said he has no codes.

Dadillac
05-11-13, 08:28 PM
I have a code reader but if the CEL isn't illuminated nothing will come up. I know that the Tech 2 can diagnose the sensors by checking their operation. But I am trying to avoid the $115 per hour charge my local dealer charges. But if it ends up being the TPS I think I have to go to the dealer. Not sure if the adjustment is a DIY thing. Can anyone tell me if it is doable?

Don

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Just checked my DVD service manual and it seems that there isn't a TPS. Instead there is a TPPS (throttle pedal position sensor). Is this accurate? I think the entire throttle pedal gets changed when replacing it. There is a relearn procedure for this that doesn't require a scan tool

Don

Superjim
05-11-13, 10:45 PM
I have a code reader but if the CEL isn't illuminated nothing will come up. I know that the Tech 2 can diagnose the sensors by checking their operation. But I am trying to avoid the $115 per hour charge my local dealer charges. But if it ends up being the TPS I think I have to go to the dealer. Not sure if the adjustment is a DIY thing. Can anyone tell me if it is doable?

Don

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Just checked my DVD service manual and it seems that there isn't a TPS. Instead there is a TPPS (throttle pedal position sensor). Is this accurate? I think the entire throttle pedal gets changed when replacing it. There is a relearn procedure for this that doesn't require a scan tool

Don

Don... That is correct.
There are two potentiometers/rheostats, that have to match when you move the accelerator pedal.
Typically if either one of them mess up, the car will go into a Fail Safe / Reduced Power mode and you can't drive over about 15 mph.

BIGDADDYCADDY07
05-11-13, 11:25 PM
hey i got the same issue with my 07 some where just a mark or so from the cold to normal temp mine acts up while coasting to a stop engine surges amost to 500 rpms then stalls or redeems it self changed gaskets ,,,plenum,throttle body gasket ,temp switch no luck either good luck we might have to resort to man

danog
05-12-13, 09:05 PM
Don

Have you check the IAC counts ,throttle angle and MAP voltage and compared them Hot and cold.
Can you post them or PM me. You may have other problems.

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Dadillac
05-12-13, 09:44 PM
Don

Have you check the IAC counts ,throttle angle and MAP voltage and compared them Hot and cold.
Can you post them or PM me. You may have other problems.[COLOR="Silver"]

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I know my scanner has live data but not sure to what extent. I will see what I can come up with and let you know. One thing I discovered is when I floor the accelerator it has a big gulp sound and then revs up. Seems a bit strange. I am still thinking I have a vacuum issue. But I will be the first to say that since cars became technical I am not very good at diagnosis

Don

Dadillac
05-13-13, 07:43 AM
So I hooked up my scanner and all of what you were looking for aren't options. TPS gives me a % mot an angle. At idle the % is 18.0 + or - 0.5. What did catch my attention was the ignition advance. This may be normal but doesn't seem right to me. At idle it is darting around at a rapid rate. High and low seem to be from 19 to 4. When I give it any throttle at all it goes up to 35.0 and higher. It is also very difficult to give this car minimal throttle. Idle speed is around 750. Trying to raise the RPM to 900 or 1,000 is nearly impossible. Even the slightest throttle brings the RPM up to 1,200 or so. Oh not sure that I mentioned this but as soon as the RPM is raised my issue goes away completely. I am still thinking I have a vacuum leak somewhere but if you have a different idea please let me know

Don

bjm6887
05-13-13, 09:44 PM
I'm having the same issues, see my thread p0300, I'm a mechanic and it has me stumped. sure feels electrical in nature, comes and goes, runs ok on highway, warmed up at idle starts chugging and flagging various lights. stuck valves seems odd, I run good gas and did fuel flush, made no diff. going to pull off intake and check for carbon build up, probably change crank sensor while in there. I know suppose to resync cam and crank sensors, also read about ecm reflash to address various issues. I think sticking valves were more problems on older nstar

Dadillac
05-13-13, 10:45 PM
I'm having the same issues, see my thread p0300, I'm a mechanic and it has me stumped. sure feels electrical in nature, comes and goes, runs ok on highway, warmed up at idle starts chugging and flagging various lights. stuck valves seems odd, I run good gas and did fuel flush, made no diff. going to pull off intake and check for carbon build up, probably change crank sensor while in there. I know suppose to resync cam and crank sensors, also read about ecm reflash to address various issues. I think sticking valves were more problems on older nstar
At least you get a code. I wish I would get a code to at least point me in a direction. I do not believe I am having valves sticking.

Don

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I'm having the same issues, see my thread p0300, I'm a mechanic and it has me stumped. sure feels electrical in nature, comes and goes, runs ok on highway, warmed up at idle starts chugging and flagging various lights. stuck valves seems odd, I run good gas and did fuel flush, made no diff. going to pull off intake and check for carbon build up, probably change crank sensor while in there. I know suppose to resync cam and crank sensors, also read about ecm reflash to address various issues. I think sticking valves were more problems on older nstar
At least you get a code. I wish I would get a code to at least point me in a direction. I do not believe I am having valves sticking.

Don

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Okay I have a question. There is a wiring harness that runs under the intake manifold that I think is for the knock sensors and cam sensor. The wire loom is disintegrated on the harness. Just wondering if this can be related. Would a faulty cam sensor or knock sensor cause the issue I am having? Knowing the loom is gone it may not be a bad sensor but bad wire.

Don

Superjim
05-14-13, 09:22 AM
Don...
If something is wrong with the knock sensor or wiring going to it... it will make your timing jump around and not be what it is supposed to be.

Dadillac
05-14-13, 10:54 AM
Well this morning I decided that when I remove the intake manifold I am replacing everything under there. So my plan is this.

Replace plenum boot and intake manifold gaskets
Replace crankshaft position sensor
Replace knock sensors
Replace wiring harness that feeds CPS, CKPS, Knock sensors
Remove and clean EGR valve
When intake is off clean throttle body to "lick it" clean

Hopefully one of these will repair the issue. All totaled there is about $240 in parts. Is there anything else that I should do while the intake is off? I do not want to have to remove the intake manifold again so I am trying to cover everything.

Don

BIGDADDYCADDY07
05-14-13, 11:20 PM
all that might be better taking it to the dlr at least you will find the problem 1st shot you can go on forever replacing parts that dont need it

Dadillac
05-15-13, 12:18 PM
all that might be better taking it to the dlr at least you will find the problem 1st shot you can go on forever replacing parts that dont need it
I don't want to sound unappreciative but am I the only person who has read about multiple paid dealer visits due to misdiagnosis and replacing good parts out. I will not consider having a mechanic touch my car until I have done the work listed. Even then I may search more.

Don

BIGDADDYCADDY07
05-15-13, 11:27 PM
I don't want to sound unappreciative but am I the only person who has read about multiple paid dealer visits due to misdiagnosis and replacing good parts out. I will not consider having a mechanic touch my car until I have done the work listed. Even then I may search more.

Don

dont blame you i got some of the same issues but getting kind of tired of it changed all gaskets trottle body cleaned egr still same issues but i know its sonmething stupid and easy just cant seem to place it no your not the only one im the same way..... nice to meet you i had some dlr warranty work done but they were sloppy mechanics go figure

Dadillac
05-16-13, 02:24 PM
I figure that at the dealers $115 per hour labor rate I can change out a lot of parts and still be cheaper than what they would charge me to replace the knock sensors and the crank sensor. that job would be three hours minimum. One hour for diagnosis and at least two hours for repairs. So that job alone would run me $500 minimum including parts. I am far less than that into this so far.

Oh I removed and cleaned the EGR this morning. EGR looked fine and no change with the cleaning. Once the harness arrives (should be by Tuesday) I will do all the other work.

Don

mike5514
05-17-13, 09:48 AM
You might want to check for a vacuum leak if you have a tester that will help. Mike

Dadillac
05-17-13, 10:37 AM
I think I am covering the bases for vacuum leaks with the intake overhaul. Aside form the intake the only other vacuum line I see is the brake booster. There doesn't appear to be any of those emissions tubes anywhere. The wiring harness arrived today so I am going to do this job tomorrow morning. Fingers crossed

Don

BIGDADDYCADDY07
05-17-13, 11:20 PM
good luck on your mission fingers crossed

Dadillac
05-18-13, 03:50 PM
Okay here goes. This morning I removed the intake manifold. Cleaned the mating surfaces and installed new gaskets. Replace the plenum. Replaced both knock sensors, the crankshaft position sensor, the camshaft positiin sensor, replaced the wiring harness for these sensors and thoroughly cleaned the throttle body. Problem solved. Hopefully this isuue doesn't return.

Don

Superjim
05-18-13, 04:42 PM
:thumbsup: :cool:

Dadillac
05-19-13, 07:12 PM
So this morning I am driving to breakfast and I notice my issue is still there. But it is way less than before. Before it would "surge" about every ten seconds or so. Now it is sporadic at best. When I say surge I mean a drivetrain surge not an engine surge. The RPM's do not raise when this is happening. If anything the RPM's might be dropping a little. But it isn't visual on the tach. So I decided to clean the MAF since I hadn't done that. After cleaning still no change. So the only thing I am left with is maybe an injector issue or maybe a transmission issue. I might just bring the car to my local $$$$dealer$$$$ to get a diagnosis done.

Don

BIGDADDYCADDY07
05-19-13, 07:18 PM
Okay here goes. This morning I removed the intake manifold. Cleaned the mating surfaces and installed new gaskets. Replace the plenum. Replaced both knock sensors, the crankshaft position sensor, the camshaft positiin sensor, replaced the wiring harness for these sensors and thoroughly cleaned the throttle body. Problem solved. Hopefully this isuue doesn't return.

Don

so what do you think it was causing your problem/?

danog
05-19-13, 10:15 PM
Don

Can your scanner do IAC counts, throttle angle? Check the IAC counts, throttle angle and map cold and hot. Match them up.
If the IAC counts and map are high or throttle angle is open excessively in comparison this may be a result of high engine load
and a torque converter and or stator support shaft may be a problem.

Can your scanner read trans temp. The trans oil cooler outlet line (the upper one to the rad cooler)
Is it real hot also do you loss of power when it happens?

One other thing have you done a Crankshaft Position Variation Learn?

Dadillac
05-19-13, 10:47 PM
Unfortunately my scanner doesn't cover those. I read up on the crankshaft position sensor learn procedure and it basically said to let the car idle for a bit, wide open throttle it until the cut off kicks in, and let it idle a bit before turning the engine off. I did this with my '02 Seville a long time ago and never had an issue with the sensors. So I assume all is well with that. I hate to do it but I think the dealer is my only hope. I would buy new injectors and see if they fix it but the cheapest price I found was about $30 apiece. If it is an injector I would assume the dealer will be able to pinpoint which one it is. Plus I guess they can make the Tech 2 force the sensors to do what they do. And if that doesn't work then I guess it would be a bad part. I will sleep on this and figure out what action I should take. I definitely will not be taking the car to the dealer before Saturday

Don

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Oh and I do not lose power at all. Aside from the issue the car runs as it should. The issue is only at idle. Once the throttle is pressed all is well again. Even when I am driving at speed and I lift off the throttle I do not feel any issue

Don

Cadillac Cust Svc
05-20-13, 11:15 AM
So this morning I am driving to breakfast and I notice my issue is still there. But it is way less than before. Before it would "surge" about every ten seconds or so. Now it is sporadic at best. When I say surge I mean a drivetrain surge not an engine surge. The RPM's do not raise when this is happening. If anything the RPM's might be dropping a little. But it isn't visual on the tach. So I decided to clean the MAF since I hadn't done that. After cleaning still no change. So the only thing I am left with is maybe an injector issue or maybe a transmission issue. I might just bring the car to my local $$$$dealer$$$$ to get a diagnosis done.

Don

Hello Don,

Sorry your vehicle is experiencing issues still. Please keep us updated with your vehicle progress and if there are questions you have, reach out to us via private message.

Regards,

Laura M.
Cadillac Customer Service

Dadillac
05-20-13, 06:26 PM
I have changed everything but the throttle body gasket. The throttle body is mounted to the crossover. Does coolant run through the throttle body? Is there a possibility that the gasket is shot and allowing some coolant into the engine? Just a thought

Don

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Okay after seeing the throttle body gasket my idea seems ridiculous. But I guess that changing the gasket may not be a bad idea. It just might be the cheap thing that has been causing the issue. I always seem to forget the cheap simple things. I will update after the install

Don

Dadillac
05-20-13, 08:04 PM
For the price of one hour diagnostics I decided to purchase 4 injectors and a throttle body gasket. With the previous cash spent on parts so far I think I am still ahead of the game. Remember reading someone paid $500 for a plenum install. I did that and a whole lot more and I am not even close to that yet. So hoping once again that this will gitterdun

Don

TulsaVic
05-21-13, 08:25 AM
Sounds like you just like to work on your car. Why don't you put on a new set of tires and brakes. Never know....

Dadillac
05-21-13, 12:19 PM
Well I do and I might ; -).

Don

BIGDADDYCADDY07
05-23-13, 11:29 PM
any luck????

Dadillac
05-24-13, 09:43 AM
Not yet. Probably do a few things this weekend.

Don

Dadillac
05-25-13, 03:32 PM
So I changed the throttle body gasket. No change. I then changed the four right side (rear) fuel injectors. So far so good. But like once before I will hold elation until I drive it awhile. Happened before that I thought I was golden only to be disappointed a morning later. I will update tomorrow.

Does anyone know if it is possible to bench test the injectors? Would like to know if they are malfunctioning or just needing cleaning

Don

BIGDADDYCADDY07
05-25-13, 11:34 PM
does this problem happen when engine temp is 8+hrs cold and the gauge is between cold and norm mark watch your rpms when coasting to a stop do they drop to about 500 rpms then stable back to norm idle this may happen when speed range is below thirty

Dadillac
05-26-13, 07:07 PM
My issue never affected RPM's. They always stayed constant. It happened cold or hot didn't matter. But by changing the 4 injectors I seemed to knock my problem down by 90%. So I think I am going to change the other 4. I still feel the "lurching" but nowhere near as often and it feels like a 10 year old is pushing the car instead of Goliath. I tested the 4 injectors I replaced and it seems that one of them tests out of spec. So since I have the problem still, albeit only slightly, I think I may have another injector starting to get out of spec.

Don

Dadillac
05-30-13, 08:00 PM
Received and changed out the remaining 4 injectors. I will find out on the drive to work tomorrow morning if the issue is gone. I checked the old injectors and found them all to be in spec. But one seemed quite a bit dirtier than the others. So if the issue is indeed repaired I will blame one bad injector and a dirty fuel system. If it isn't repaired I am well on my way of having a lot of new parts on my engine that still is acting up

Don

Dadillac
06-02-13, 07:08 PM
Update: My problem persists. But it seems to only happen on a cold engine. So I decided to do a computer reset. I disconnected the negative and positive battery cable. I touched the two cable ends together for half a minute. Left the cables disconnected for 30+ minutes. I will see how things go when I drive to work in the morning. Another strange thing. When I started the car after the battery disconnect my stereo still had memory. My stations still were there and the time was still accurate. Also my memory seat was still set. Is this stuff that is downloaded into the computer or is there some secondary memory battery somewhere? Never had that happen before

Don

stormnn
06-03-13, 07:58 AM
After installing a new battery my station pre-sets were still there but the time had to be re-set. Service tire pressure monitor came on but re-set itself the next day. Drivers window express up is gone. Down & passenger down & up still works. Haven't gone in the book to figure that out yet.
Norm

Dadillac
06-03-13, 07:31 PM
Express up is easy to fix. Just roll the window down. Then roll it up. Once the window reaches the top hold the up button for about three more seconds. That is all there is to it

Don

Dadillac
06-15-13, 06:26 PM
UPDATE: Changed the MAF yesterday with no change. Then I installed a new EGR this afternoon. So far so good. Have taken three "run around" trips and have yet to feel the issue. There was lots of stop and idle in these trips and seems to be repaired. I will update again in a week if all goes well. I will update sooner if the issue is still there.

Don

BIGDADDYCADDY07
06-16-13, 07:25 PM
is this a slight or heavy roughness in the idle and do you feel a slight flat spot in acceleration like in the old carbs just off idle

stormnn
06-17-13, 01:18 PM
Did that, works great, thanks.
Norm

stormnn
06-17-13, 06:54 PM
Sorry for hi-jacking a thread .Iwill start a new one next time.
Norm

Dadillac
06-17-13, 07:26 PM
Well my problem still persists. I have an appointment next Monday at the dealer. Hopefully they can figure it out without emptying my bank account

Don

hazcaddy
06-17-13, 07:38 PM
Not to be nasty, but by now have you spent enough time (at whatever dollar-amount you rate your time worth) and money on parts (sounds like a bunch) for it to have been worth a trip to your dealer to get the codes read in the first place?

I'm the type that once they started putting plastic covers over the engines said "enough already" and paid to get it done. Not that I didn't know then (I took the cylinder head off a straight-6 - decoked it - and it started first time) but I sure know now that if I can afford a Caddy, I can afford to get it fixed by folks that have all the diagnostic and restorative tools...

Dadillac
06-24-13, 11:36 AM
Went to the dealer today. They said they scanned it and found nothing that would cause this problem. So I would assume that it isn't an electrical issue. They said the first step for them was to check the fuel pressure. My car should be 60 psi. They found 42-45 psi. Diagnosis tree says to change the fuel pump. So I ordered one from Rock Auto and will install when it arrives. I will update when it is in. I will see this thread through to the end. To help anyone in the future that may have this same issue

Don

Dadillac
06-25-13, 07:02 PM
Fuel pump did not fix the issue. Going back tomorrow for more diagnosis

Don

BIGDADDYCADDY07
06-25-13, 11:29 PM
that suck's how much did they charge for your visit???

Dadillac
06-26-13, 06:49 PM
$125 for diagnostics. I paid $220 for fuel pump and installed myself. Problem is now more pronounced since the engine is getting full fuel pressure. The dealer has the car and will do more diagnostics tomorrow. I told them to drive it before working on it as the problem is worse on a cold engine. I feel it is a transmission issue. I guess we will see tomorrow.

Don

jazoo
06-26-13, 07:55 PM
I paid $220 for fuel pump and installed myself.

Don

Isn't the fuel pump located inside a gas tank? So you first emptied the tank and removed it from your Caddy. I guess you had to purchase a fuel pump removal kit, removed the fuel pump, cleaned the tank from debris, and then installed a new fuel pump. So how long did it take for this project?

Dadillac
06-26-13, 08:50 PM
Isn't the fuel pump located inside a gas tank? So you first emptied the tank and removed it from your Caddy. I guess you had to purchase a fuel pump removal kit, removed the fuel pump, cleaned the tank from debris, and then installed a new fuel pump. So how long did it take for this project?
In the trunk is an access panel. It is under the trunk carpet. Remove the panel and you will see the fuel pump. Unplug the two electrical connectors and the one fuel line. Remove the hold down ring and remove the pump. I replaced the entire "capsule". So the install took about an hour to an hour 15. Not hard at all and don't have to remove or empty the tank. I took the old pump capsule and figured I would remove the pump from it. Just to see how difficult it would be had I opted to just replace the pump. Glad I bought the capsule. Removing that pump wasn't easy and I broke stuff along the way.

Don

jazoo
06-27-13, 04:39 PM
Don,

You are my hero!!! I love your persistent and I hope your perseverance is paid off to your satisfaction soon. One would think that the Cadillac dealership should be able to get to the bottom of the problem and fix your vehicle. One could ONLY hope for a satisfactory solution from the manufacturer's authorized representative.

Dadillac
06-27-13, 08:49 PM
Well I think we got somewhere today. They did more diagnostics and hooked it up to the machine. Found a consistent misfire on cylinder 8. Mechanic installed a known good used coil and the misfire went away. Told me to drive it for a week and let him know. The charged me $155 for diagnostics. Did not charge me for the coil. I told the mechanic that if the problem stays away I will buy a new coil and return the used coil back to him. So far so good. Drove the car three times and felt nothing. But the real test is in the morning when the engine is cold. That is when it is always present. But I feel good about it this time

Don

big greg
06-27-13, 09:33 PM
Didn't you already try new coils?

----------

Never mind seen you just tried #4.

Dadillac
06-27-13, 10:12 PM
No I only replaced coil number 4 due to it looking rusty. I had planned on moving the new coil around from cylinder to cylinder but didn't do it. I assumed that a coil misfire would set a CEL. I guess I should have done that.

Don

big greg
06-28-13, 07:27 AM
Hope u got it.

Dadillac
06-28-13, 10:18 AM
So I drove the car today and it seems to be almost corrected. The tech told me that he saw a severe misfire on cylinder 8 and a really slight misfire on cylinder 1. So he put the used coil in number 8 and it made the issue go away. He didn't address number 1. So I bought two coils today through Amazon. When they get here I will change out 8 and 1. That should get me to perfect again.

Don

jazoo
06-28-13, 07:52 PM
Don, You mentioned in Post #64 that you “went to the dealer today. They said they scanned it and found nothing that would cause this problem”. Then in Post #71, you said “well I think we got somewhere today. They did more diagnostics and hooked it up to the machine……..”. So is this continuation of Post #64 or is this a different dealership? I hope you got it fixed finally.

Don, couple of questions; 1) did your scanner or on-board diagnostics (OBD II) computer pull any codes at all?, 2) Shouldn’t you be looking @ replacing all eight coils instead of just two (I don’t remember that you mentioned the odometer readings on your vehicle)?

Dadillac
06-29-13, 04:43 PM
First diagnosis was with the Tech2 scanner. There was no fault codes using the Tech2. So they went to general diagnostics and started with fuel pressure. After that there was some other machine that I guess graphs ignition. Don't ask me what it is because I haven't seen it. But the tech said it was graphing all crazy with a misfire. So that's when he changed the coil and it quieted the graph down. My car has 65,000 miles on it and I am not yet ready to replace 8 coils at $50 a pop just yet. If they were half that I would do it. Also my scanner showed no codes. It only reads emission codes that would trip the CEL. And the CEL never came on so my scanner said all things were good. Oh and it was the same dealer.

Don

Superjim
06-29-13, 11:37 PM
I have a little over 130,000 on mine and I guess I have been lucky.
Except for a half case leak that was fixed under warranty it has been pretty much trouble free.
Other than that, it has never had a wrench on the engine or transmission.
No ignition problems or fuel problems ... at least not yet.
It still has the original plugs in it... I probably need to change them...

Jim

RicktheRealtor
06-30-13, 01:07 PM
I have a little over 130,000 on mine and I guess I have been lucky.
Except for a half case leak that was fixed under warranty it has been pretty much trouble free.
Other than that, it has never had a wrench on the engine or transmission.
No ignition problems or fuel problems ... at least not yet.
It still has the original plugs in it... I probably need to change them...

JimI bet your plugs aren't carbon fouled! ;)

Dadillac
07-01-13, 07:26 PM
New coils arrived today and I got them installed. So far so good. I will know in the morning if the issue is 100% gone or not. I am positive it is

Don

BIGDADDYCADDY07
07-01-13, 11:27 PM
the misfire you had on a scale of 1 to 10 what would you describe it was and was it noticeable when at normal temp???

Dadillac
07-02-13, 11:44 AM
It varied in intensity. The major symptom was a feeling of the car wanting to drive while my foot was on the brake. Quick misfires in rapid succession. When the engine was fully up to temperature the frequency and intensity died down significantly.

I drovebto work this morning to a butter smooth engine. Issue is completely gone.

Don

BIGDADDYCADDY07
07-02-13, 11:24 PM
nice that what we like to hear enjoy the ride brother:bouncy:

jazoo
07-03-13, 07:54 PM
It varied in intensity. The major symptom was a feeling of the car wanting to drive while my foot was on the brake. Quick misfires in rapid succession. When the engine was fully up to temperature the frequency and intensity died down significantly.

I drovebto work this morning to a butter smooth engine. Issue is completely gone.

Don

Congrats!!! Don, I'm so happy for you. Your hard work (& perseverance) is finally paid off.

HASSAN4477
07-04-13, 02:43 AM
Have ur cats checked out or the resonator this could explain y no codes its after all the extra sensitive stuff. Did you clean you're manifold on the inside I foind alot of carbon in mine also try sea foam to clean the carbon from the cylinders

RicktheRealtor
07-04-13, 10:11 AM
It varied in intensity. The major symptom was a feeling of the car wanting to drive while my foot was on the brake. Quick misfires in rapid succession. When the engine was fully up to temperature the frequency and intensity died down significantly.

I drovebto work this morning to a butter smooth engine. Issue is completely gone.

DonNice to hear. Congrats. BTW, Happy Fourth to all my American friends.

TulsaVic
07-04-13, 04:37 PM
I have a little over 130,000 on mine and I guess I have been lucky.
Except for a half case leak that was fixed under warranty it has been pretty much trouble free.
Other than that, it has never had a wrench on the engine or transmission.
No ignition problems or fuel problems ... at least not yet.
It still has the original plugs in it... I probably need to change them...
Jim

Guess this is testament to the belief that the N* was built to be driven hard ....