ArcticWhiteZ28

I have a 1994 Z28 (see sig for mods) and had a problem with hesitation in all gears and RPMs. Checked fuel pressure and found it to be at 21 psi so i replaced the fuel pump. Now it definately is better but it still has a problem accelerating. I don't think its missing of hesitating (not nearly as bad as before the fuel pump replacement) just seems to be lacking power. Anyone have any suggestions?

Colin91Z

Mine had a similar problem at one time, I ran some injector cleaner through it and problem solved. And I don't mean the kind you dump in the gas tank, I'm talking about pressurized kind. Give it a shot, it couldn't hurt, it could only help...

Z95m6

Did you replace the fuel filter too?

ArcticWhiteZ28

yes with a Delco

CamaroSS30thAnn

plugs/wires? are u runnig rich ?

SteveZ Z-28

Where did you get the pressurized can type (I am assuming you are talking about the stuff that you connect to the fuel rail)? I have been looking all over for it and can't find it. I have looked at AutoZone, Advance Auto Parts, NAPA, and Carquest. Carquest was the only one that had it, but they had a "professional" type that was a kit for like $160. I know that the pressurized can stuff is expensive (like 70 or 80) but not $160.

ArcticWhiteZ28

plugs and wires are less than 25k and it was said to be running lean (this was before the pump replacement) not rich and I have not had time to scan it since but i do not believe it to be.

UPDATE:

I scanned the car today and it is running rich on both banks. I guess the coil is my next part to replace and to do the ICM Mod. After that i have to go with the opti

ArcticWhiteZ28

I replaced the left side O2 and waited to do the right side cause it looked like a PITA when i scanned it (before replacing the fuel pump) the left bank read lean while the right bank was ok. I would think they should both be leaning out if there was half the fuel pressure in the fuel rail. Now the left bank is slightly lean while the right bank (the one that read ok before) is reading a heavy rich mixture so im going to replace that sensor since it is still the old one and update this post after

ArcticWhiteZ28

Funny story, i got under the car today to do the o2 swap and what did i find, cylinder 2s plug wire had came loose from the opti Boy i feel stupid but at least i found the problem i am happy about that. Hopefully this solves it but im not too optimistic about those prospects.

TMDZ28

clog cat? when i had mine, it did the same thing. turned out to be a clogged cat

ArcticWhiteZ28

how would i know if the cat is clogged, or should i say how to check it?