well guys, recently installed headers and exhaust, and have a weird miss/stumble
occurs between 1500 and 4k..
it like...jerks, but doesnt miss.
car is also running really rich.
is it just because i need a tune? maybe a burnt plug wire?
i dont think its my optispark because i had no problems until i did the headers saturday.

car is a 94, and i deleted all emissions, so that might be it too, idk

 

You should get a tune with the headers that you installed...
If that keeps up replace the opti and if your still having problems it might be your fuel pump going bad.

I replaced every part on my car and it still stumbles, come to find out I have a weak fuel pump with a 32psi runnning and a 40 psi max reving and when I shut it off I have no fuel pressure so its hard to crank over at times.

 

Did you replace the O2's? I know they can fowl from the coating burning off. I would definately check the wires and anything you might have messed with when you did the last set of changes. Did you delete the emissions when you did the headers and was it correctly done? I think this is also something to look into. I try to do as few things as possible at 1 time so if something is wrong i have less things it might be from.

 

Double check all the easy stuff, make sure your plug wires have tight connections and there are no exhaust or vacuum leaks present.

 

yeah, today i was driving it, and it drove fine, no problems at all. Only thing i did last night was double checked plug wires, but none of them felt loose or anyhting

 

Sounds like what is going on in my Z28. I am waiting on a new AC Delco FPR that will be here on Thursday. A Racetronix pump is also in the near future.

 

im kind of wondering if its my fuel pump, not entirely sure.
i know i need a tune BAD though, so thats the next thing on my list

 

I have the same problem,now I have to keep my foot on the gas just so it can turn on.some times it jolts but it doesn't miss,and sometimes it just doesn't start.I have a small oil leak and a coolant leak that i just found.can that happen if the opti got wet?

 

definately sounds like your opti going out

im getting a computer tune, and doing OTVC wires finally

 

I don't think the tune is going to do much other then attempt to be a bandaid to a different problem.

 

after i installed my headers my fuel pump went out. probably coincidence but i had the same "stumble". my car was hard running when first started up but after a little bit it would run fine under normal driving. but the second i would get on it, it woudl fall on its face. it turned out i was only putting 20 psi out for fuel pressure.

 

well, the problem came back. it happens after it warms up, it'll stumble until it hits 4k or so, then runs fine. It'll run fine for like 10 minutes when its still cold, then it gets to operating temp and it stumbles. It'll stumble for like 10-15 minutes, then throw a code and it'll run fine..... Completely has me stumped.

I think what it is, is my o2 sensors reading ti running rich, and then keeps trying to lean it out....

 

may have a exhaust leak and weak 02 sensors

 

If it is shooting a code, I would definitely get it scanned. That may lead you to the problem right there.

 

well, it hasnt done it all day now, and im not sure what to think of it. Think it might just be some bad gasoline or something. Im gonna pick up a can of seafoam and flush her out