90 Cutlass Supreme - Only starts in the morning

[waredbear]

Believe it or not that is what the car is doing.

1990 Cutlass Supreme with the 3.1L V6. Daughter was driving home when it shut-down. She said it was running rough at stop lights. I talked to everyone I could and there were those on the fuel side and those of the ignition side. I was ignition so I changed the plugs and wires. It started......we turned it off, cleaned-up, my daughter tried to start it to leave and it wouldn't start. It turns over and tries to start when you pump the pedal then just turns over and over. Maybe it is fuel....we drop the tank the next day and put in a new fuel pump. It starts and purrs like a kitten. Turned it off to clean-up and it won't start again. Go out the next morning and the stupid thing starts up...runs smooth...for about three minutes and then dies. It will not start the rest of the day. Go out the next morning and it starts up again....runs for about three minutes and then dies. No spit...no sputter...just dies. Long story (about two weeks worth) made short. I changed the plugs and wires, fuel pump, fuel filter, fuel pump relay, crank shaft position sensor, air filter (only because it was dirty), and the Electronic Control Module. Tested the coils and Ignition Control Module at the auto parts store and they pass. Checked the grounding fire on the injectors and they are all good. I have 40 psi on the fuel rail and it holds it during cranking and I have good spark on the plugs.

The only change in the symptom is when I changed the ECM out with a used one from the junk yard. The car ran for 20 minutes until I turned it off...problem fixed...but then it wouldn't start again. So that was the problem. I went to the parts store and bought a new one for $80. Put it in and the car ran for five minutes and stopped. The next morning the car cranked and ran long enough for my daughter to drive it to a friends garage. He put it on the computer and there were NO codes....NO CODES?????? He called today to say he doesn't know what the problem is and for me to come get it.

So...what is the problem???????????

I've read a lot of posts here first trying to find an answer. Could it be the Ignition Control Module even though it passed 10 test on the bench? I don't want to put another $90 into this thing on a guess. So experts...give me your suggestions.

Thanks
Reid

[maxwedge]

If you have fuel pressure at the rail and spark, assuming the injectors pulse it should start, see if you have injector pulse or spray carb cleaner into the intake see if it starts. Post back

[waredbear]

I used a test light that shows negative and positive voltage by touching the end to the connector and either a red (+) or green (-) light will light up. I read on the forums about a Noid light...I don't know if this is one or not. Anyway I was getting a solid green light on one side of the injector plug and a flashing green light on the other. I took this to be good since the injectors get a ground pulse to fire the fuel.

I sprayed starting fluid and gas into the intake and it would try to start but wouldn't quite get enough to start.

Todays Update:
The mechanic called yesterday and said he couldn't fix it without spending hours and hours troubleshooting. He read the computer and received no codes as stated above. He also checked several things I already had. The only thing he did different was put a spark tester on two plugs and said there was sufficient spark after the car died so he doubted it was the Ignition Module.

One thing I didn't mention above. My daughter couldn't get the car to stop one day because the key was stuck in the ignition. She drove it to this mechanic and he stopped the car and replaced the ignition switch. When you would crank the car the key would stick in the "crank" position and you would have to turn the key back to the "run" position. This morning the car would start but when I turn the key to the "run" position it would stop. It did this to me twice. The third time I held the key over in the "crank" position for a couple of seconds and then the car started. I drove it home and let it run for 15 minutes. I turned it off and it started again...and again...and again.

I have two thoughts.... ... One is the computer I replaced needed to be cranked a few times to reset and go back to a normal setting after all the work I did and the vacuum lines I replaced that were broken. The second thought is that the switch it bad. Or maybe a combination of both. I ran the car down to the part store to return the steering wheel puller and turned the car off to clean-up. I came back out and the car wouldn't start..again. I turned and held the key and finally got it to start. I'm going to take it back to the mechanic and have him replace the ignition switch again.

What do you think.

Thanks again.
Reid

[maxwedge]

One way or the other you must correct the ign switch issue, but I think this may be an ign module problem, with strong spark it should start with starting fluid.

[meester]

Ever get it figured out?
Did you see the entry at this website about the guy that found one bad injector caused the whole group to fail.
Also, my 91 Cutlass with the 3.1 holds 43 psi after cranking to 46. When I start the motor it drops to 36. Stabbing the acclerator will make it jump to 46 or so. If this has a vacuum regulator my drop to 36 may be normal. I don't know if it does have a vacuum regulator though. If a drop is normal then yours holding a higher number may be a sign of pressure that's too high.