automatic tranny causing occasional engine surge

Hi all,

I have a 92 Silverado (198k on the truck). Engine and transmission have been rebuilt and generally runs great. Transmission has a shift kit installed and works really well most of the time. However, sometimes while sitting at a stop light, the engine will act like its under load and almost die and then surge back up to idle. It will do this several times in succession. I think the transmission is trying to engage, but doesn't get all the way there. If I shift into neutral, the symptoms will go away. Any thoughts?

As for the work done on the transmission, I don't have any details. I bought the truck used last year and the transmission had been rebuilt about 6 months prior. Shifts great and generally have no complaints except for this annoying bit.

Thanks,

Spudspuppy

bump...

I would be willing to bet it is not the tranny. I have had two Fords that have done the same thing and in both cases it was the idle air controller.

I'm not so sure about the idle...when it surges, it loads up the rear end when it does this, making the truck lurch a little. If I wasn't standing on the brake, I would go lunge forward....but then again, I could be wrong..

Mine does this too.... That's the high quality gm Torque converter. Not putting gm down, when they work, they WORK, when they don't, they cause headaches like this.

I have a 93 K1500 suburban that does the exact same thing, Initially the fuel pump went out & I thought it was this also, Changed the pump and it rans fine but still has the same problem your are describing, I have changed the Idle Air Control valve and Nothing changed, I changed the entire distributor, coil, cap, rotor, and the truck runs strong but still has this little annoying quirk about it, I was thinking of chaning the Fuel Pressure Regulator as a precaution. Also I have a B&M electronic shift kit, one that connects to the ECU.