The engine for my 1994 chevy silverado Missing/Surging/Sputtering when idling or at a stop and it sometimes will die, but it starts up right away afterwards. if I put my foot on the brake and push on the gas a little so that the rpm's are around 500 or so it runs fine, and it runs just fine well I'm driving. it has a 5.7 V8 and about 165000 mi. on it, I have also read in some other forums that it might be the Idle Air Control Valve but i haven't tried that yet as I'm not sure where it is on the engine.

 

Really? It is idleling lower than 700 is an issue.

 

I have A k2500 pickup and its doing the exact same thing. I have to do the same as you do too, but I haven't replaced the IAC valve yet either and ive replaced almost everything like the tps, vacuum lines, break booster which can be your problem too, I've also replaced the map sensor, the cts sensor, fuel filter and I didn't replace the egr sensor since it didn't have any clogs in it and all I have left in mine is the iac valve, fuel pump and the head and manifold gaskets which I really hope isn't the case. But I am definitely going to replace the iac valve next. Im hoping that this will get me closer, Since my truck is still surging and after every new part it sounds like its getting the smallest bit better. Im wondering if on yours its running to rich too you can find that out by taking the vacuum line off the break booster and it will idle how it should be.