New Engine Dies Need Help

arrowshooters · September 1, 2009

Had the timing set on my new/rebuilt 98 5.7 today. It was pretty far off so I figured that was the cause of my engine dieing when coming to a stop. Well my engine ran a whole lot better and I thought I was out of the woods, but after awhile it started dieing again.

This issue does not happen when the engine is cold, only when it is up to temp and driven a little bit. I will be slowing for a stop and it just shuts off. I can pop it in neutral, start it right back up, and off I go as if nothing was wrong until the next time I slow down either for a stop or a turn. It acts like two things to me: either a huge vacuum leak (but a vacuum guage has me well in the green and I sprayed everything I could find with Brake Cleaner), or it's like I have a manual trans and slowing down without the clutch in.

I am sooooooooo stumped.

dlewis1111 · September 1, 2009

Had the timing set on my new/rebuilt 98 5.7 today. It was pretty far off so I figured that was the cause of my engine dieing when coming to a stop. Well my engine ran a whole lot better and I thought I was out of the woods, but after awhile it started dieing again.

This issue does not happen when the engine is cold, only when it is up to temp and driven a little bit. I will be slowing for a stop and it just shuts off. I can pop it in neutral, start it right back up, and off I go as if nothing was wrong until the next time I slow down either for a stop or a turn. It acts like two things to me: either a huge vacuum leak (but a vacuum guage has me well in the green and I sprayed everything I could find with Brake Cleaner), or it's like I have a manual trans and slowing down without the clutch in.

I am sooooooooo stumped.

Idle air control dirty or bad? Did you adjust timing with the connector on the firewall disconnected? (I think this applies to yours)

Sir Dan · September 1, 2009

I had a 94 chev cavalier that did this same exact thing. It was the torque convertor lock-up solenoid for the overdrive gear on the tranny that was bad. It would fail to release the convertor from lock and kill the engine when coming to a stop. Very common on these I guess, but not sure about any other vehicles. The overdrive will not kick in until a certain temp is reached in the tranny fluid, so that would explain the problem not happening until it heats up. Hope this helps...

arrowshooters · September 1, 2009

I had a 94 chev cavalier that did this same exact thing. It was the torque convertor lock-up solenoid for the overdrive gear on the tranny that was bad. It would fail to release the convertor from lock and kill the engine when coming to a stop. Very common on these I guess, but not sure about any other vehicles. The overdrive will not kick in until a certain temp is reached in the tranny fluid, so that would explain the problem not happening until it heats up. Hope this helps...

Makes sense, so I will add that when we pulled the engine we pinched the wiring harness between the trand and the lip on the fire wall. I pulled the sheath off and inspected the wires and found nothing wrong but maybe the wire to the Converter was damaged. Can someone with a scan tool ID this problem?

arrowshooters · September 1, 2009

Had the timing set on my new/rebuilt 98 5.7 today. It was pretty far off so I figured that was the cause of my engine dieing when coming to a stop. Well my engine ran a whole lot better and I thought I was out of the woods, but after awhile it started dieing again.

This issue does not happen when the engine is cold, only when it is up to temp and driven a little bit. I will be slowing for a stop and it just shuts off. I can pop it in neutral, start it right back up, and off I go as if nothing was wrong until the next time I slow down either for a stop or a turn. It acts like two things to me: either a huge vacuum leak (but a vacuum guage has me well in the green and I sprayed everything I could find with Brake Cleaner), or it's like I have a manual trans and slowing down without the clutch in.

I am sooooooooo stumped.

Idle air control dirty or bad? Did you adjust timing with the connector on the firewall disconnected? (I think this applies to yours)

I had the timing set with a scan tool. No need to mess with connector.

arrowshooters · September 1, 2009

I had a 94 chev cavalier that did this same exact thing. It was the torque convertor lock-up solenoid for the overdrive gear on the tranny that was bad. It would fail to release the convertor from lock and kill the engine when coming to a stop. Very common on these I guess, but not sure about any other vehicles. The overdrive will not kick in until a certain temp is reached in the tranny fluid, so that would explain the problem not happening until it heats up. Hope this helps...

Makes sense, so I will add that when we pulled the engine we pinched the wiring harness between the trand and the lip on the fire wall. I pulled the sheath off and inspected the wires and found nothing wrong but maybe the wire to the Converter was damaged. Can someone with a scan tool ID this problem?

Would this thing sitting for the last 3 months have anything to do with it?

arrowshooters · September 2, 2009

If there are no other easy checks for me, I am to the point of a trany shop or the dealer for driving diognosis. Thanks.

superjim · September 2, 2009

If there are no other easy checks for me, I am to the point of a trany shop or the dealer for driving diognosis. Thanks.

Just to see if it the transmission killing the engine....

go drive down the highway fast enough to have it in high gear with the converter locked.

Now exit on to the service road and start stopping.

When you get down to about 20 or 25 mph...slip it to NEUTRAL" and "THEN" stop.

See if it dies.

If it does..it ain't the transmission.

arrowshooters · September 2, 2009

I have actually done thins in town since the converter locks up around 35 or so. When I start to slow I will pop it into neutral and it will not stall. I then can put it back into drive and all will be well until next stop.

I am actually taking it in to the stealer tonight to have them drive it with a laptop hooked up. One possibility I guess is that the Computer could have lost it's mind from the battery being disconnected for the last 3 months. We'll see.