[michiganblkman]

1990 DEVILLE DIAGNOSTICS

I have been a lurker on this board for a few weeks now. Lots of good stuff I have been reading. So I am basically writing this to contribute something to the group.

A few weeks ago, I bought a 1990 Deville at an Auction for 1000. The seller wanted 2500. But I ended up being the highest bidder, and he agreed to sell it to me for that price. I hate to admit it, but I am an impulse buyer.

Here is the deal on the vehicle I bought for 1000

-1990 Grey Cadillac Deville
-117,000 miles
-Clean/almost mint exterior.
-Ok inside (smokers car, some leather wear on the interior)
-When I drove it sounded like all it needed was a tune up. (I am risk taker)

Here are the symptoms (I have seem some of these similar symptoms in other posts in the forum)

1.Rough Idle
2.Hesitation
3.Poor gas mileage (8 MPG)
4.Occasional service engine light coming on
5.Sounds like the engine is "missing" when I idle or accelerate.

I knew it was a gamble. After I bought it here is what I have had done to the vehicle.(On the advice of some shadetree mechanics an my own intuition)

1.Spark plugs
2.Distributor Cap
3.Spark Plug wires
4.Engine flush
5.Oil Change
6.Trans Flush
7.Injector clean
8.Map Sensor
9.Fuel Filter
10. A tank of 94 octane fuel with a bottle of gas treatment.

After these repairs it still ran its same, less than stellar performance.

So I broke down and made an appointment with a Cadillac Dealer (I wont mention the name but if you email me I will tell it to you) in the greater Detroit area
(figure you can get good caddy service in the Motor City? Wrong). The dealer had me agree to 3 hrs of service @82.50 and hour to give me a THOROUGH DIAGNOSIS. I figured what the heck, 250 to figure out the mystery and erase all doubt. So I dropped the car off and waited for their call. I was very disappointed with what I got for 250 dollars.
The rep gave me a call while I was at work, and told me:

1.at least one of my fuel injectors was bad,
2., it MIGHT be my fuel pump,
3., it MIGHT be my camshaft,
4. And/or it MIGHT be my PCM (computer module, but I thought it was called an ECM).

When I got to the Dealership, I paid for the service and asked the rep for a diagnosis sheet of the findings. Again I was disappointed at what I got. I got the mechanics chicken scratch on a piece of scrap paper which had some barely readable fuel injector readings (Was I expecting too much to expect the findings on a formatted, organized piece of paper clearly outlining what was discovered? For 250 dollars?). I WASNT expecting a NASA diagnostic, but I WAS expecting something semi scientific to base further troubleshooting and courses of action. Especially in a joint where the service reps wear suits and ties. (Is there a market if I designed an Excel spreadsheet that mechanics could use to report and categorized diagnostic findings.).

But I guess the crux of the matter is, they said my injectors were bad.

So what are my next courses of action? I plan on getting a second opinion this weekend from another shadetree mechanic that I met in Autozone when I was there to get my fuel filter. (He had on a Jaguar dealership service workshirt, and he said he USED to work on caddys back in the day). Depending on what he recommends, new fuel injectors (@60 each) might be in my future. An idle speed sensor(from rbnj post) maybe? Who knows? I might just try putting them on myself.

I will keep you all posted on how this turns out.

Post to the group or email me directly about your opinions, advice, chastisement, etc.

Humbly submitted to the group at the 1500 dollar mark (1000 for the car, 500 for the stuff I have done so far).

P.S. I knew I was taking a chance when I bought this vehicle, so I don’t want this post to misinterpreted as me whining.


[email protected]

 

[DeVillish]

you didnt list air filter as somthing you replaced, if you didnt you might wana try that before you drop another 100 bucks. Also get a service manual if you can, or at least one from auto zone and start checking your emisions crap. My EGR vlave is bad and thats is setting of my check engine light. Also run your codes and post em up here.

 

[matts93z34]

I have the same problems with my ASG 5.0L motor. I haved changed all of the same things that you have. If you could let me know what you do to fix all of those problems. Also do you ever notice when the car hesitates is the battery light on. My car wants to stall every time the wheel is turned all the way and every time the battery light is on. But if you could keep me updated with any progress with your problems.

Thanks,
Matthew

 

[michiganblkman]

I am taking it in to have it looked at by Mr. Shadetree that I met at
Autozone tomorrow. Barring any new and enlightening information I am possibly looking at

1.New battery cables (as per rbnj's post on the "After 3 weeks, problem solved about my '93 DeVille" thread)
2.Idle speed sensor (as per rbnj's post on the "After 3 weeks, problem solved about my '93 DeVille" thread)
3.Fuel Injectors (as per the Dealers Diagnostics)

in that order (from cheapest to most expensive)

Hopefully,i will be able to thoroughly debrief (interrogate, lol) Mr. ShadeTree and get a
halfway decent diagnostic (i.e. Computer codes, etc). Pick his brain a little bit, find out what he knows, doesn’t know.

In response to the earlier question about my air filter, it looked good when the tech checked it when I had my oil changed. I was standing right there when he inspected it, and it looked good (almost new).

BTW, thanks to forum members for your much appreciated posts and page views. Its good to know that there is someone out there who cares and is listening.

I will post the results here when i find out more.

The saga continues......

 

[michiganblkman]

The saga continues........

Got my car back.


I got a call from him today at about 4 pm. He was saying that he thinks my ECM is bad because he is getting no erro codes at all. That wasn’t very good news to me. He also told me a bunch of other stuff he did and told me to come over in an hour. So in the meantime I logged onto ebay and checked to see what
Cadillac ECM's were going for. I was relieved to see that they were only 30 bucks on ebay. On the drive to his house I stopped by AutoZone to check the prices on new ones. Only 90 bucks, which isn’t bad.

So I get to his house. First let me start with Mr. Shadetree. From the looks of his home garage,(he had the garage door down when I was over the first time), I have to upgrade his misnomer from “Mr.ShadeTree” to "Mr. Shadetree ++" or "Mr. Shadetree Deluxe Edition". Even better,why don’t I just call him by his given name “Pat”? I have seen independent garages that didn’t have the extensive array of equipment and tools that Pat has. As a matter of fact, I think he has too much stuff. From the looks of his neighborhood (working middle class), I don’t think it will be long before the chief of the Homeowners Assn sends him some nasty notes about the "Repair Shop" look his garage has. But at any rate, that’s a good thing for me. I was impressed. He can do entire engine overhauls onsite with ease with the equipment there. At least I see the guy is dedicated to his craft. His wife was sitting on the porch and gave me that "he has wasted another Saturday working on cars when we could’ve been doing family stuff" look on her face when I said hello. Pat has my car in the driveway, with the hood up and to my surprise it’s running better.....not 100% better but about 90% better. Heck, I was happy with that.

Here is what he fixed/worked on/checked:

1. New coil (he showed me where the old one was arced through)
2. New cap and rotor (he said the one the other shade tree put on was crap)
3. 2 Cans of super duper fuel injector cleaner (I don’t remember the brand)
4. Cleaned my plugs and checked the gaps on them.
5. Verified ignition and timing.
6. Compression check (180 psi)
7. Checked injector integrity.

After some small talk about what he had done and other concerns,he told me to put in a tank of Sunoco Ultra Blue with an STP gas treatment to see if it further cleans the injectors out. (Pat remarked that the super duper cleaner he used, he has seen it remove salt off of fuel injectors). I took his word for it, but I kind of wondered how one could get salt on fuel injectors. Oceanic scuba diving maybe? Road salt? I will have to do a forum search on that one.

Something that confused me is he recommended that I get an oil change. I had one of those last week along with an engine flush. When I told him that, he removed the oil dipstick and said my oil "looked and smelled funny". And yes it did look dirty. Super neglect from the previous owners maybe? But I am an agreeable guy, so I will get an oil change tomorrow and put 10W40 in (his recommendation).

So I paid the man, drove straight to Sunoco and put the fuel (only 94 cause they were out of ultra blue) and gas treatment (2) in and guess what, it runs better. About 95% now. I will drive it this week and see how things go

Here is a recap.


Here is what he fixed/worked on/checked:

1. New coil (he showed me where the old one was arced through)
2. New cap and rotor (he said the one the other shade tree put on was crap)
3. 2 Cans of super duper fuel injector cleaner (I don’t remember the brand)
4. Cleaned my plugs and checked the gaps on them.
5. Verified ignition and timing.
6. Compression check (180 psi)
7. Checked injector integrity.

Total cost to me $150.

Some things that he says I definitely need in the near future:

1. A new Cam seal (hence the oil residue on the right side of the engine)
2. A new belt that the oil from the cam seal leak has soaked thru and virtually ruined. Will probably break soon.

Some things that he hasn’t ruled out:

1. A new ECM (it bothers both him and me that the car isn’t producing any error codes, even when he tried to artificially generate a code by disconnecting/reconnecting the map sensor)
2. He hasn’t ruled out needing fuel injectors, but he did say that he could get some cheaper than the 60 a piece AutoZone is asking. (Don’t ask don’t tell?)

Some things that I haven’t ruled out

1.Battery cable (from "rbnj" post in another thread, I guess I am hard headed)
2. Idle speed control (from "rbnj" post in another thread, I guess I am hard headed)
3. I am concerned why my oil “looks and smells funny” when I just got an oil change last week.
3. Fuel injectors. (via Pat’s procurement channels)

Humbly submitted to the group at the 1650-dollar mark.

I think I will make Pat my regular mechanic now.

I will post again about Wed or Thurs to let you know how things are going.

 

[Isac Chicago]

I got my 90 deville for a $1000 too and it was running fine. Only problem was the service engine soon light kept coming on (E49).
A mechanic friend of mine thought I had a problem with the ignition timing and he "helpt" me correcting it. This car was never the same again, it has been 2 years now and the timing is still off no matter how hard I try to fix it.
At one time I had the car tuned up and I didn't pay attention to the metal ground strap in the distributer cap and it caused the engine to run very rough and stall. when I found out about it I had to replace several parts within the distributer.
I thought I should share my stupid mistakes so you guys can avoid the costly problems I had.

 

[Snyder81]

I got my 90 deville for a $1000 too and it was running fine. Only problem was the service engine soon light kept coming on (E49).
A mechanic friend of mine thought I had a problem with the ignition timing and he "helpt" me correcting it. This car was never the same again, it has been 2 years now and the timing is still off no matter how hard I try to fix it.
At one time I had the car tuned up and I didn't pay attention to the metal ground strap in the distributer cap and it caused the engine to run very rough and stall. when I found out about it I had to replace several parts within the distributer.
I thought I should share my stupid mistakes so you guys can avoid the costly problems I had.

So Isac, is this a problem you were ever able to correct? My 90 DeVille and several others on this forum also have a problem with the check engine light coming on due to code E49, or E049 as many refer to it. There is another thread or two just on this forum about this code.

Here's one:

http://www.cadillacforums.com/forums/showthread.php?t=1712

 

[michiganblkman]

-Installed New battery (had the old one tested at autozone, after installing the new battery my ECM held codes. Showed E30, E98)
-Installed New ISC (After seeing the codes and reading the forum)

Still runs the same.

Still sounds like an engine miss.


Totally disgusted at the 1800 dollar mark (Price of car included)

Possible next course of action? Maybe i will get the ACdelco plugs and wires this time. The expensive stuff.

I need some time to think. It shouldnt be this difficult.

 

[Maximln]

Have you had the catalytic converter checked? This seems to be an often overlooked piece of equipment that can really affect the way the car runs. I also had a 90 Deville that seemed to have an idle problem. The problem was real apparent when I had 6 people in the car one time, going up a mountain road. I knew there was a problem when kids on skateboards were overtaking me. The catalytic converter was plugged but during normal driving, was not apparent. Once it was replaced, the car ran a whole lot better and I could do 90mph uphill instead of 9mph.

Max

 

[brianroark]

for sure

check the injectors sounds like a bad injector or two
ohm them out...same symphoms as my 90 deville

does it seem like the tranny shifts late at low rpms?

 

[michiganblkman]

Fuel Injectors

Well it was the fuel injectors.

Thanks to all of those people who recommended those in the first place.

Its rumoured that using bad gas (i.e. 87 octane) over the years can clunck up the fuel injectors.

The ohm readings on my old ones were out of whack (i.e. Higher than normal ohm readings, or totally open).

FYI, i know i shouldve bought new injectors, but the new ones are 60 a piece at autozone. If it was a 2000 caddy, i wouldve bought new ones, but then again...what are the chances of the fuel injectors on a 2000 caddy going bad.

I am dealing with a 1990...do i got some injectors from the junkyard that ohmed out.

Had Pat do the work for me. If you guys are in the Detroit area (East side) i can give u his number. He does good work. And he explains things so you can understand them. Tells you why he recommends something. etc.

Just an update to let u guys know what eventually happened.

Thanks to all in the group, Members, Moderators, Viewers, Lurkers, Posters. (I wanna thank God, my mom, my producer,LOLOL)

 

[michiganblkman]

Also wanted to mention that i replaced the ECM also.

Now it runs like a caddy is supposed to run.

 

[stickpony]

I got my 90 deville for a $1000 too and it was running fine. Only problem was the service engine soon light kept coming on (E49).
A mechanic friend of mine thought I had a problem with the ignition timing and he "helpt" me correcting it. This car was never the same again, it has been 2 years now and the timing is still off no matter how hard I try to fix it.
At one time I had the car tuned up and I didn't pay attention to the metal ground strap in the distributer cap and it caused the engine to run very rough and stall. when I found out about it I had to replace several parts within the distributer.
I thought I should share my stupid mistakes so you guys can avoid the costly problems I had.

sounds liek a loose timing chain to me.. they are known to go bad in the 4.9L caddy's after 100k miles or so..