Tach to zero, engine dead, until...
 

The car is an SE. It is tuned to spec, and otherwise runs excellent.

About 20% of the time when I'm clutching and changing gears, the tach will go all the way to zero, engine dies, until I let back out on the clutch. This clutch change is the ones you make when you're turning in to another street or going over a pothole, etc. The regular gear shifting pattern is undisturbed.

I've checked the service manual for deceleration problems and the the items it listed I recently checked for.

Someone on another thread (FD) had mentioned their flywheel was too light and it caused their problem. I've not changed mine.

Any ideas?

jeryj

Does it otherwise idle okay when just sitting in neutral?

Also, are you saying that the tach first drops to zero, then a few sec. later the engine dies, or that they both happen at the same time? What I'm getting at is trying to figure if it's a stalling problem or an electrical bugaboo.

Thanks for the reply.

Under the "normal" scenario, the tach does a "slow" drop (thanks to the dashpot etal), then I let out on the clutch, and the revs begin to pick back up with throttle.

When it has its "colon attack", the darn tach/engine doesn't slowly go down. It will drop like the fuel has been cut off (this occurs with my foot OFF the gas and the clutch pushed in). Obviously when I let off the clutch, the car momentum starts it back up.

It only does this during a "prolonged" shift pattern (holding the clutch in while going over a speedbump, etc). It may be occuring on "regular" gear shifting, but since I make the shift so quickly, the car doesn't have time to manifest the problem.

Either way, this only occurs about 20% of the time during the "prolonged" shifts.

jeryj

I'd start by making sure the TPS is set properly, and the BAC valve isn't gunked up.

Its not really momentum starting the car, its the rear wheels turning the tranny, and the tranny turning the engine when you let the clutch out, simulating a starter by rotating the flywheel.

Anywho, check the dashpot and TPS for proper adjustment. I had a TPS that would intermittently fail, and cause the vehicle not to start. Its a hard proplem to diagnose cause its intermittent.

I've had this happen to me in the past. It was a poor connection on one of the fusible links. Check there.