Ok, i have replaced everything replaceable for the most part on my car. new plugs, wires, cap/rotor, fuel filter, cleaned throttle body, blocked off bpt and egr valves and every time i start my car up, under light throttle there is a lot of hesitation and jerking. If its stopped, it sounds like it wants to stall. I have checked for vacuumn leaks and found none. Also, when driving, if i give it some gas and let off, this is when cold or warm, the car jerks back pretty good. Unlike my best friend chris (nismoser) 91 classic, which is nice and smooth when you let off. Do you guys have any suggestions, because this is driving me nuts. The only thing i can think of taht hasnt been changed is the pcv valve, and the o2 sensor, but my gas miealge is great (27-29 mpg). So any and all help will be apprecaited. Thanks again......John. I did notice it did start happening around the same time that i switched over to Gastrol syntec blend oil, but i dont know if this has anything to do with it. Thanks again....

Sounds like your iacv (idle air control valve) has taken a shit.

did you ever resolve this problem?

I have a 94 SE-R, and it has similar problems

on cold starts, it will die if I don't give it a little gas for the first 5 seconds or so.. after letting go of the gas, it idles at 800rpm during warmup(should be about 1200?), and during this time it nearly(but doesn't) stall when I start driving and clutch back into neutral. having the a/c on doesn't affect it much, but turning on the headlights nearly make it stall as well. when warmed up, it gets a little better, but not completely normal..

plugs/cap/rotor has been changed(needed it anyway), MAF regrounded, TPS ok.

how much does an iacv go for?

I doubt it's the IACV. You should check the air regulator. It is what controls cold idle, not the IACV. It's bolted to the underside of the intake manifold and is pretty easy to reach from underneath the car. Did you guys check your base idle first?

I think you guys should check both. If you have any questions it gives good advice on SER.NET.

We solved John's cold start problems by turning up the idle 100 rpm. I guess the tach is just off that much.