Here's a little back history real quick. Finally was able to buy my first Third Gen after years of owning an 4th gen. Barn find in a guys shop has been sitting for 5 years under a canvas cover. Black on black leather 89 WS6 GTA. My jaw dropped, purchased the car, brought it home on a trailer. Also guy i purchased from said the car went through a bad divorce, (curious if something could have been done to sabotage car).Put in a new battery and attempted to crank it. No start, but would run on carb cleaner. So started chasing fuel delivery issues. Ended up replacing the fuel tank, sending unit, fuel filter and fuel pump. Tried to start again, was only running on a few cylinders. Ordered new injectors, adjustable fpr and gaskets. Replaced all that and then car was finally running. Went ahead and replaced ignition control module, cap and rotor button. Now to my issue. Car will run and drive most of the time until it reaches operating temp. Then it will just die like you turned the key off. You can cycle the key off and back on and it will restart but if you just let it idle it will die within a few seconds again. Sometimes if you hold the throttle o er 2k rpm it will stay running then if you try to give it some quick throttle it will die immediately. Cleaned maf sensor, idle circuit in the throttle body, and sprayed carb cleaner all over in engine bay looking for vacuum leak and havent found any. Have fuel pressure guage hooked up to monitor fuel pressure and has good pressure while idling and running. Also looks like there's a small oil leak somewhere behind the distributor because it's a little wet on the firewall back there. Ecm has already been replaced as well as that was a prime suspect. Can anyone on here help me diagnose this and get my baby driveable??? Thanks for any and all help.

 

The oil leak could possibly be the rear intake seal (China wall) or the oil pressure switch on the rear ledge - or both.

I don't see in your post whether you scanned for error codes, or if the SES light is on or flashing. Any information on that would be helpful.

If you can force open-loop mode it may reveal whether the system is trying to trim fuel excessively, advance spark excessively, or do anything else detrimental to keeping it running.

 

Sorry, yes I did scan for codes and only does code 12. Also ses light comes on when car shuts off but goes away after key has been cycled and will start right back up and will run for maybe 10seconds then shut off again.

 

Hey Vader,

Long time no see! Reactivating as AdyeWS6GTA is a friend, and I suggested he post here.

For additional context on the issue: When the car shuts off, the CEL comes on, but if you attempt to restart the vehicle right after it dies, it will just crank and crank, without ever catching. You have to power cycle the car off, then back on, to get it to crank and fire. I'm wondering about a potential VATs issue, but don't know enough about VATs to help, as I never had those issues with my '87 back in the day.

Another note, this 'shutoff' doesn't always happen once the car goes into closed loop. When I saw the car this weekend, it shut off before it reached operating temperature. Then, once the issue happened, it repeatedly shut off (3-4 more times) until we got the car back into the garage. Once we returned to the garage, it would sit and idle just fine until you attempted to rev it, then it would shut itself back off. Then, it will only crank back up if you power cycle.

Given that the car went through a 'bad divorce,' I wonder if a previous owner did something to the vehicle that could cause these symptoms or as mentioned previously, given the randomness, possibly a VATs issue. Given especially the number of things that have already been replaced.

 

Also vats has been (bypassed) with the original key in the original lock cylinder hidden under the dash thats still wired in. Has a plain set of keys that start the car.

 

If there is no "Security" lamp function when the engine dies, it may not be a VATS issue. A description of how that indicator acts on power-up, when cranking, and when it shuts off could be helpful.

 

!!!!!!!!!!!!!!!FIXED!!!!!!!!!!!!!

Fixed the stalling issue people, turns out it was due to a bad pickup coil in the base of the distributor. Replaced the pickup coil and she hasn't cut off since! Thanks you guys for all the advice and things to check it has really been an adventure! Glad to be a part ot the Third Gen Family now!!!!