gerrythibodeau

Well first let me start by saying what i have. I own a 91 Z28, it was originally a 305 tpi but i now have in it a 350 tpi .30 over. it also has a comp racing cam, new roller rockers, msd distributor, and accel ignition components.
The problem that I've been having is that i cant get the car to run smooth. The Idle is all over the place, and when i accelerate the engine pulses. Its almost like a misfire. but i try resetting the timing and get it running smooth and after some driving it starts pulsing again. I have checked all my fuel injecters and they all seem to be good. I'm not really sure what to look for here. Any Ideas? thanks

jordo2114

hey welcome man just to give ya a heads up people probably wont be to responsive since you posted a technical question in the appearance and detailing section but all i can say is start with basics like possibly a vaccum leak or check any sensors that might be bad are you getting any codes any thing like that would be more helpful

gerrythibodeau

Thanks, i just found this sight, im still figurin out where everything is.
one thing i did forget to mention is that the emissions system is basically non existent right now. no o2 sensors, no smog pump. i havent installed them yet. im not sure how that will effect things, but i have been lookin for a vaccum leak, nothin so far.

jordo2114

well i am not to familiar with tpi because i got stuck with the ol ccqjet but i do belive you must have the o2 sensor as it is one the key parts to letting them ecm know how rich or lean the car is running if you dont have any o2 it should be throwing a code

sailtexas186548

well thi will get moved into the right section soon, but while im here i think i may have your anwer. my o2 sensor fell out when i was just installing my headers, and the car would surge badly, and would idle ok for a few seconds, then get real rough. put the o2 sensor in, i bet it'll smooth it all out. if that doesnt work, check your knock sensor, my header was barely touching my k-member, and only really hit it hard when i got on it, but when it did it was giving off a false knock signal, so the ecm retarded the timing and the motor ran rough, because it would retard the timing, the motor would slow down, stop hitting the headers on the k-member, then the false knock would go away, the enine would speed up again, then it woul happen all over agian, making it feel like it was running rought, so check for things that could cause false knock if it continues after you put in an o2 sensor. also, did u put in a 350 prom chip when you did the swap and bigger injectors? hat could also be the problem