This problem became evident during and after my dyno tune session, but I was "aware" of it prior when I was at traffic lights.

On the dyno, the hp vs rpm showed drops. The tuner spent hours fine tuning fuel and spark and after consultiing with other techs, decided it would have to be something mechanical. The stall converter ( a 2500 lock up) is a probable culprit. I did the stall converter shield off for a while and noticed later when replacing the shield that some stones or other things had chipped and slightly dented the converter. How much of this would have a bearing on it? (The dents are not to big or too deep.)

At stop lights, when I take my foot of the brake to let the car roll/push forwards, it has a jerky, lunging motion. This really only happens when the car is warm. I dont see it happening when its cold.

I dont think its ignition cause there is not evidence of a mis or other symptons that would lead me to believe it is the wires and plugs. Can a stall that is mechanically going bad do that?

I am stumped as to what this lunging is. Hopefully someone on hear can chime in with something useful or a costly diagnosis will be sought.

 

dirty injectors? Maybe time to use fuel system cleaner.

 

So you dont think its the torque converter? Interesting, now that you say that, I was passing by a jiffy lube and thought that I have 89k on my 94 and the fuel system never cleaned.

It could be a cheap fix for $60. I dont know if i trust chevy to do it. Jiffy lube you can watch.

When you say fuel cleaner, you mean the additive or the jiffy lube/chevy cleaning?

 

A leak in the intake track will cause the car to surge as unmetered air is bypassing the MAF.

 

I dont believe my intake is the problem. Except for this lunging, the car is fine. I am doing a gas mileage test right now. If its bad I am either gonna remove the 3.73's and go 3.23's and/or change out to stock torque converter.