Auto tranny ?

Hey

I've got a 93 chevy van with an auto trans in it. It hesitates and stumbles at part throttle pulling away from a stop. If I put it in 1st or 2nd it seems to do better but you can still feel a small stumble. Is the transmission shot? Will new fluid and a filter fix it? Thanks for the help.

Brian

Unplug the EGR valva and test drive. If its better, buy a new one.

Doesn't sound tranny-ish to me. Sounds like plugged catalyst.

Doesn't sound like a transmission issue. Sounds like input or output, so what they said.

The van idles smoothly and will rev smoothly in park and neutral, I should have included that info in first post. Does that change your thoughts. I will check the EGR valve on Monday

Thanks Brian

Doesn't change my thoughts at all. Revving the engine places very little load on it. When you are actually asking the throttle for power, it really puts the volume through the exhaust.

Seriously... pull the O2 sensors and see if it improves. The leak you create before the converter could tell you everything. For that matter, loosen the bolts that hold the exhaust to the manifolds. Create a big exhaust leak before the catalytic converters and see if that changes things.

For that matter, cut a huge hole in the bottom of your catalytic converters and smash out the honeycomb catalyst. If it improves things, you know you found the problem. If it doesn't, you just made a performance exhaust

If it doesn't change it, you have a problem with one of a few hundred things... but don't worry; we'll figure it out.

BTerj wrote: Hey I've got a 93 chevy van with an auto trans in it. It hesitates and stumbles at part throttle pulling away from a stop. If I put it in 1st or 2nd it seems to do better but you can still feel a small stumble. Is the transmission shot? Will new fluid and a filter fix it? Thanks for the help. Brian

Hesitation and stumbling is never a tranny issue. Always an engine issue.

ive had fuel filters give the same symptoms, start and idle with no issue, once in gear would stumble pretty bad. and fuel filters are cheap

Just switched out the EGR valve with no change. Went and got a new fuel filter. See if that helps.

Brian