Extreamly hard to start. Runs bad up to 3500rpm's. Runs great after that. It has new fuel pump and filter. Plugs, wires ,cap and rotor.

 

any codes????

someone may correct me, but before a certain threshold in the throttle, the computer takes readings from several different sensors to determine proper AF ratio, etc (i.e. o2 sensor, MAF, coolant temp, TPS, etc.) after the threshold is met like at WOT, the computer disregards many sensors and goes off preset tables. so maybe one or more of those items are out causing it to run bad at partial throttle. what do you guys think?

 

*nods* That sounds completely true to me. I had a Mustang GT a few years ago we were trying to build into something (project failed, but that's a whole 'nother story!!) and I was told the same thing for that car that you stated here. Yeh, good question on the codes, because if I understand correctly if it's an O2 sensor, the computer should be throwing a code.... I am definately no mechanic, just sharin' what little info I believe I have heard previously.....

 

No codes. I also put a new temp sensor in.

 

was up, is it running rich? could be a stuck injector. or does it run better when it warms up?

 

You say runs bad, sluggish, misfire, no power? Several things come into play. Injector clean, exhaust restriction, doubt it though since you have power after 3500 rpms. How is it on a cold start? Hard to start, misfire then straightens out? Could be air flow meter, hows the throttle response? Things to think about?[8D]

 

Also, have you checked ignition timing? Make sure it is in base timing when you set it by unplugging Brown/Black wire to set timing.