1991 K5 shuts off when put in gear!!!

[Greg Ducato]

The locking part would be due to the bearings seizing up.
Remember, when you are sitting still in gear with the engine running, half the converter is bolted to the flexplate, so it has to turn with the engine.

The other half is attached to the input shaft of the transmission.

There are bearings between them.
That is what lets the truck be stopped in gear.

If the bearings seize up, the engine will be directly coupled to the transmission as if a clutch were released on a manual transmission.

Sometimes the bearings don't seize completely, just gall up enough to put more load on the engine. Enough to stall it at idle, but not enough to stall it when you give it more gas.
Just like partially releasing a clutch.

J.

On the GM lockup converter there is only one bearing and it is between the pump cover and stator. If this bearing were to become galled it would raise quite a racket whenever the trans was in gear but could not lock the converter components internally. If the converter is locking up on this trans it would be by virtue of the clutch being applied. If it is the clutch being applied the truck would act like like it had a standard trans that you forgot to push the clutch in on every time you come to a stop. Shudder, chuggle, die.

 

[Stomis]

My monte carlo did this. My vote is a vacuum leak your never gonna find IE back of intake manifold.

 

[Philly87]

What about the TCC (torque converter clutch) switch/solenoid not allowing the converter to unlock? I've heard of this before but never actually experienced it with my own vehicle.

Here's some info on testing...

 

[GMC1977]

if the torque converter wasnt unlocking it would still go but would be very very sluggish like it was pulling 2 houses behind it. i vote vaccum leak

 

[skidog1us]

Not to argue with anyone...I had a similar problem. Truck would start fine and die on take off. It ended up being a bad EGR Valve. Replaced it an all is good now. Something to consider before tearing into the TC.

 

[maxumpower]

OK fellas.........after a few weeks of trouble shooting changing every part on my TBI i found the distributor rusted like a old chevette. I am going to change it and set the timing and see what happens.

 

[maxumpower]

K5 shutting of when in gear....PROBLEM SOLVED

after changing all the TBI electronics and spark plugs, vacuum lines, the last thing i looked at was the cap and rotor. When i pulled it off the distributor was completely rusted! Here is a pic. Thanks everybody for your help. Now if i can find someone to change all 8 fuel injectors on my 2002 duramax i'll have it made!

 

[smartcarkiller]

Nothing makes me more mad than when it ends up being something stupid and easy to fix. It never fails to be the last thing to check after several hours of wrench turning and dollars spent. good to know its fixed though. Just think of it as preventive maint.