I have a 1985 IROC, the 305TPI blew so I replaced it with a 350 TPI (L98) and have been through two transmissions (700R4) since the fall of 2007. Just put a reman by hydromatic 700R4 in it, the trans makes it through all the gears BUT when the car is started, its starts for maybe 2 seconds and then stalls out. I disconnected the EGR valve and that helped a ton, but it still "lopes" or "surges", but its worse with the EGR connected. And yes I plugged the EGR vacuum hose. The TPS and MAF sensors are both BRAND new, So I am stuck. What else could be the problem? All the wires, cap, and plugs are new with the rotor button, and everything is plugged in normal. It actually started missing, surging, loping, whatever its doin just after the trans was installed. It will idle, after the EGR valve is off and plugged, around 750RPM and will surge to about 1000RPM and continuously do it, and the performace is sucking since this has been happening. PLEASE HELP!! What else is left? The trans shifts all gears, it can hit 80MPH on the highway without beating it, but getting there the car shakes like crazy and surges, somewhat worse, as the RPMs raise. Please let me know what else I can do, thanks in advance!
Dan

 

check for vacuum leaks, they can cause that. also a dirty iacv could do it too. a temporary fix is to turn on the ac so the idle goes alittle higher, that way it wont stall

 

All the AC components are out and I will turn the throtle up and Ive heard the IACV motor a few times now so I will try that next. Thanks for the advice, if anyone else has any ideas please let me know.
Thanks
Dan

 

a good way to detect vacuum leaks is to spray around the suspect area with the carb and choke cleaner. if the idle goes higher youve found your leak area. also u can use the same spray to spray the inside of your throttle body and see how much crud comes out. chances are if it starts dripping black grease its pretty gummed up in there, also that might help your idling problem alone. but re reading your first post, you noted its performance isnt what it used to be.

id start by checking fuel pressure. if thats okay then id still ohm check the injectors, sometimes they can flood your cylinders. after that id check the ignition components like sparkplugs and whatnot, rotor, ignition coil, get the ignition module checked aswell.