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-   -   1990 LE, 3800 Vin "C" engine stalled after driving (https://www.gmforum.com/1987-1991-93/1990-le-3800-vin-c-engine-stalled-after-driving-308332/)

BonnevilleJeff 11-15-2014 03:24 PM

1990 LE, 3800 Vin "C" engine stalled after driving
 
1990 Pontiac Bonneville LE, 3800 Vin "C" engine, 89K miles:
This car used to start like turning on an electric motor...instantly, just like new...

Car stalled after driving a while (engine up to operation temp, not overheating) and would restart after 5-10 minutes (to cool off?); seemed to happen repeatedly, so thinking it was heat related, when it would stall, I would splash a glass of water on the crankshaft sensor area, and it would immediately restart (and be fine "until heated up again?")
Tried this "fix" quite a few times with "success", and so assumed I should replace Crank Position Sensor with new (Done!)
Car wouldn't start after this and seemed "out of time" (stumbling, misfiring start attempts, flooding)
Discovered coil only fired on 4 out of 6 cylinders (so 1 coil bad out of the 3 on the Magnavox-style coil pack) and also out of spec re: ohm readings, so... replaced coil AND the ICM with new, and now car seems to "want" to start (more normally "freewheeling" sensation than before, almost like no sparks plugs in it; slight firing sensation but also some hesitation) but still won't "catch" and start...

Wonder if the 4 wires coming from the CKPS to the ICM my suspected trouble?
(Don't know why they would suddenly go bad, as they aren't a "motion part" that might be subject to disconnection or breaking, since most all wiring isn't normally disturbed from "where it rests")

Spark plugs were replaced in June and assumed good; relay and fuel pump noises all "correct", and fuel pressure at rail seems strong (6"-8" spray column from schrader valve... I know, I know)
All fuel injectors check at over spec, but all are at 16 ohms (vs 12 spec?)

What to check/fix to finally figure this out? Still a very decent car...
Thanks for all replies!

BonnevilleJeff 11-15-2014 04:42 PM

Additional observations to above:

The car has no DTC codes stored (???)

Is the ECM not throwing codes, and also not running on the predetermined/default values???

This is a great opportunity to learn but very frustrating...
Much thanks!

jwfirebird 11-15-2014 06:22 PM

You check for spark after the icm? Plugs get corroded and or loose pins when old and they get disturbed. Might be something with that plug

Tech II 11-16-2014 07:44 AM

Simple engine....easiest to diagnose when it won't start...

Yes, you have to put a fuel pressure gage on the rail....you can also try spraying carb cleaner into the throttle body while someone cranks the vehicle...

Check for spark at the end of each ignition wire?

Check for injector pulse with a noid light?

Try starting with MAF sensor disconnected?

Not sure if repeated wetting of the crank sensor would have an affect on your harness, or the contacts in the harness connector....do a drag test on all the female pins of the crank sensor harness end, and also on the connector at the ICM....do an ohm check of the wiring from the crank sensor wiring to the ICM, while flexing the wires....

How did you install the crank sensor? Is it possible the vanes on the harmonic balancer may have hit the sensor?

BonnevilleJeff 11-16-2014 09:26 AM

JWFirebird... the big (10 pin) plug that inserts into the ICM?

TechII... checked for spark onj wires before COIL and ICM replacement... (should check again?

No "Noid Light" check as yet, only just the injector internal resistance(s) - all are even at 16 to 16.1 ohms...

Still need to do check of wires from CKPS to ICM plug I guess!

Crank sensor mounting position checked and rechecked before finally tightening everything up..., all visual and feeler gauge measurements show balancer vanes right in the center of the sensor cut-outs, so probably nothing bad happening there...
(had also compared ohm readings on old and new CKPS's... old one was obviously whacked out, and the new checked out as perfect readings... as did the new coil...

Guess I gotta do some checking before I get back with some results...

Thanks to you guys!

Tried MAF test before... no difference whether plugged in or not...

jwfirebird 11-17-2014 07:11 AM

like tech2 said you have to check it all, the ckp end and where it goes to the icm

jimmyw 04-04-2015 08:46 PM

When one shuts down,it`s best not to overlook the Ignition moduale

Dogluvr 06-20-2015 08:00 PM

1990 LE, 3800 Vin "C" engine stalled after driving
 
Bet anything you need an ignition module.

Dogluvr 06-20-2015 08:07 PM

1990 LE, 3800 Vin "C" engine stalled after driving
 
Wow...i just read the rest of your post never mind the icm..:banghead:

Mike 06-20-2015 09:21 PM

Yea, please also pay attention to thread dates. Anything beyond 6 months old, don't reply to.


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