civic_hatch34

I have a 1990 Civic Hatch with a DOHC ZC with the Zc tranny. The car doesnt seem run right at all. At times it seems to pull fine, and others it just wants to run like crap. When in warm weather it would idle high and ping alot. Even now when its cooler it still doesnt run right. When i downshift it jerks really bad, i think it prolly has something to do with the amount of fuel in the engine, but cant pin point the problem. The ECU currently in my car is a PR4?? Is that the preffered ECU?? Could that be the problem? Mods are ractive header, full exhaust - no cat, B&M fuel pressure regulator. I have been messing with that alot to see if i could fix the problem, it always seems like whatever i do doesnt make the car any better. I ran the car at the strip and it ran a 16.5, which i wasnt happy with due to a guy being there with the same car, engine, tranny, and mods, and he ran a 15.3. I NEED HELP!! Any info would be useful, i am new in the import world and would like to have this setup tuned as best as possible so i can start on other bigger mods. Thanks

88crxSi

the pr4 ecu is out of a 90-93 integra. it is meant for a b18a engine (1.8l DOHC Non-vtec).

it is my guess that you are gettin too much fuel.

fear not. it can be chipped w/ proper ZC fuel tables by some1 on here.

but.. easier things you may want to try first. Change the fuel filter lately? using good gas? do u have a fuel psi gauge so u know what you adjust it to? if so, what is the psi at idle and WOT (yes, they are different if u did not know).

if u didnt know. you are probably asking how do i check the under hood guage at WOT while driving. simple. with the VAC line ON the FPR it will simulate idle (car running of course) remove the VAC line and it will simulate WOT (no vac). stock pressures are 30ish w/ vac line on and 38 w/ vac line off.

good luck.. post back what your findings are.

civic_hatch34

I havnt checked the fuel filter. Where is it located on the Civic Hatch? How could i get my ECU chipped with the ZC fuel settings? Would I better off just buying a new ECU, like a PM7? I have been running the fuel pressure at 24 lb, if i turn it up anymore it will just sputter at 4,000 rpm and will not go. What should i do?

MikeJ-2009

Fuel filter is the black round thing at the top of the passenger side firewall. There are two lines going into it. Sometimes the fuel filter gets clogged with ---- over time and can prevent good fuel delivery. If you go to "Engine Management" here on the site, you'll be able to find someone to chip your ecu. Turbo edit may work for your situation, but you want to make sure everything else is in working order as well.

quickcrx702

change your fuel filter before you do anything. its cheap(around $15), doesn't take long to do, and can make a major difference. after my swap, my car wouldn't go past 5000 rpms. it would just bog and act like i was hitting the rev limiter. what i did was change out my fuel filter, and i also swapped in a civic ex fuel rail(had one just lying around). after that, i had no problem hitting the real rev limiter. like stealth said, its that round black thing with two metal lines going to it. good luck.

civic_hatch34

Changed the fuel filter, totally different car. Shifts smoother and accelerates better. Thanks for the help guys. I am looking into a pm7 ecu and maybe a turbo upgrade. Thanks again. Lata

Jeremiah