I have a 95 auto SE. When I'm driving around with my foot on the throttle, whether I'm at WOT, or just barely touching it, the second my foot leaves th pedal, and there is no force on the throttle, the rpms drop suddenly a few hundred rpms, then jump back up to normal.

Say for instance I was at 3k rpm, and I let off slightly, well with the gears turning and, the rpms would naturally fall a couple of hundred RPM due to gear lag, but mine goes about 3-4 hundred, and then rebound back up to normal.

Any suggestions? I'm thinking maybe my IAC valve? What about a TPS? What are the symptoms of a failing TPS, and a failing IAC valve?

Thanks.

 

Sounds like your torque converter is failing.

Gear lag? Thats a new one..

When your engine and tranny are up to operating temp and your crusing about 35 MPH your torque converter should lock. Your RPM's should stay put when you let off the gas. Tapping the brake will release the T.C. and the RPMs will fall. Stepping on the gas a bit will also release the T.C. and your RPMs will rise.

 

It seems more as if your torque converter isn't locking. This is controlled by the Transmission Control Module. This is the thing to look at as well as the systems that activate it, I would imagine a solenoid or hydraulic device within the tranny. Often the problem can be the other way around, the TC stays locked and ends up stalling the engine.

Your IAC wouldn't affect this, nor would your TPS. If you had a TPS, it would affect the drivability of the car, ie: bucking, irregular power curve, stalling, irregular idle.

 

You guys know what 'gear lag is' It's when you are in a low gear and you let go of the gas and the car slows down. All cars do it, also know as engine braking.

My engine and tranny stay as one, no slipping, so like lets say if I were to be in 2nd at like 45 mph, and then let off the gas, the engine speed will go lower than the intended natural slowing of the car via the low gears, like a semi stall, and then climb back up again to normal, and start slowing the car at a normal rate, weird, and hard to explain.

I know, it stays locked when you are just cruising, and when you apply slight harder force, it unlcoks, I know this. It happens when O/D is off, on or I'm in 2nd or 1st.