Ok 1st the history.

I got then car needing and oil pan and and some exhaust work..
so 3 months later, I get the motor back in and the exhahust is all fixxed, (flotech headers and y pipe with 3" out the back, no cat)
I got it running giving code 33 fixxed that, (MAP was not connected.)
now it runs with no codes, but hesitates when I try to accellerate. (BAD)
It's is pretty steady with a little throttle, any thing over 15-20% throttle, hesitates and stumbles. Stays that way through WOT, at WOT it wil stumble, then pick up.. but not like I think it should.
I have:
new plugs, wires, cap and rotor, ignition module,

The cooling fan runs all the time, hot or cold,

Any advise as to where to go from here?

Thanks,
Chris

 

Double check that all of your plug wires are on correctly and not mixed matched. It is easy to do whenever you take them off.

Also, make sure that the 02 is plugged in.

 

Man, that sounds an awful lot like my Camaro. When I first got it, it needed exhaust, as it was totally stock and had been sitting for sometime down in Florida/Alabama. It only had 69K original miles on it, but had been a little neglected by sitting around. I replaced the exhaust with a Catco Cat and Flowmaster American Thunder 3" system. The car would hesitate during accelleration and is just plain a dog at WOT. I have replaced almost everything (cap, rotor, plugs, wires, vaccum lines, O2 sensor, Coolant Temp Sensor, Knock Sensor, rebuilt TBI, cleaned injectors, replaced Fuel Filter, and installed the other mods listed in my signature. I have even switched out ECMs to make sure that wasn't the problem.

Needless to say my car runs a lot better than it did when I got it, BUT it still does not drive right. It still has hesitation, especially at WOT and I cannot figure this out. I am thinking maybe it is with my ESC (Electronic Spark Control), or fuel pump/system. It is very frustrating though, so I feel your pain. Let me know if you figure anything out!

 

fuel pump? can you run temporary gauge on windshield to check FP when you get on gas?

 

Thats exactly what I was going to say. Funny, this seems to be the problem of the week. Check your fuel pressure, you may have a failing pump...

Bruce (90RS305)

 

i have some similair problem but when the car warms up it gos away.

 

That sounds like a sensor problem that is leading to a computer adjustment that is causing you that. Sorry, but I don't know which one would fix it.