Craigenstein

My son just got his first car. It's a 1991 Honda Civic DX 2-Door Hatchback, with the 1.5L SOHC engine. The car has sat in a field for 11 years. The former owner didn't remember much, but said it did the same thing when she stopped driving it (that's why she abandoned it). So I don't think it has anything to do with the time it has sat. I pulled off the timing belt cover and determined that (while not running) the timing was right on (timing marks lined up perfectly, belt was tight and in good condition, and #1 cylinder was at top dead center (TDC)). We've replaced the ignition cap / rotor, plug wires / plugs, and air filter (almost all of the obvious, general maintenance stuff), and it still idles rough. Generally, when it first starts (engine is cold), it starts right up, and runs pretty well. It runs VERY well over 1500 RPMs. Then, when engine gets warm after about 3 mins, the idle RPMs drop, and it runs roughly. If we take it for a drive, it's all you can do to keep it running at a stop sign/light (it will start right up again, but you need to pump the gas and keep the RPMs up to get it going). We have a new fuel filter and Idle Air Control Valve (IACV) for it, but haven't installed them yet.

I can work on / rebuild / etc any old Chevy, Dodge, or Ford, but I don't know SQUAT about these little Japanese engines...I need some help. First of all, what is a "dizzy" (I see that in a lot of posts). Next, how would one go about "cleaning / replacing" the fuel injectors. Furthermore, does this car have a mechanical or electrical fuel pump, and where the hell is it located ? And, finally, what other components would one check / replace (in addition to the ones listed) for these symptoms ?

THANKS in advance to all you Honda experts that enjoy helping out us non-Honda idiots...

Craig

jlicrx

dizzy = distributor

it has the electric fuel pump which is inside the fuel tank - have to drop the tank to replace it - probably not the problem if it runs

do you have a Check Engine Light showing on the dash? if so, you need to see what the trouble codes are - if you have a problem with the fuel injectors, you should get a Check Engine Light

pumping the accelerator pedal on a fuel injected engine does nothing as it doesn't have an accelerator pump like a carburetor

could be that you need to replace the Oxygen Sensor - this would usually also cause a Check Engine Light

Craigenstein

THANKS ! Great info, and a big help. No...I don't have a CEL illumintated. Tonight, I'm changing out the IACV and fuel filter, as well as draining the tank and replacing with new, clean fuel (and some injector cleaner). I plan also to "dip" the injectors in a heavy-duty solvent in an attempt to clean them. I'll put it all back together this weekend, and let you know how it goes.

Thanks again for the help / advice !

Craig

CivicDX89

It could be the electronic choke so i would check that out if the problem continues.

Super Chicken

Do a compression test first. I've seen several of these 1.5's with burned valves or too tight of an adjustment on the valves (too tight leads to burned valves). Leaks from the valves will cause it to run poorly at low RPM, but will still run OK higher up.

Craigenstein

Thanks. After the previous posts and subsequent troubleshooting, I still have the same problem(s). I've pulled both injectors and dipped them in solvent for 24 hours (they looked clean anyway), replaced the IACV, checked all the vacuum hoses, replaced the fuel and air filters, cleaned the throttle body, replaced the plugs, wires, cap, and rotor...same symptoms. So, I bought a compression tester to see if it's got a bad cylinder or two. Anyone know the compression specs on this thing ? Any additional ideas ?

Thanks again for all the help,

Craig

cherroneballs

I just bought the same car, but an automatic, and dumped around 300 dollars into fixing the problem, and no luck, mines rough at idle but then its really rough once its in gear. i hate dpfi! nothin but junk. i've never seen one run worth a dang. and i know these cars in and out, its frustrating. i was thinking injector or catalytic converter next. idk. its fine except when i come to a stop sign and its rattling itself apart.

ih8sndq

I have the exact same car and mine has just recently developed this rough idle. I know that mine has a blown head gasket and I thought his may be causing the rough idle. I'm in for some more information if anyone finds anything out and I'll post anything I find when I get off my butt and actually go look at it.

Super Chicken

Compression numbers don't matter unless they're below about 120psi. What you want to see is if they are close i.e. within 10% or so. If you have one with 180 and one with 130 you've got a problem, if they are 145 155 150 and 140 you're in OK shape for a high mileage 1.5

cherroneballs

mine also isnt throwing a cel, idk. it just gets rough when its in gear, like due to the load.

Craigenstein

Pulled the heads after troubleshooting everything else that I could. #3 and #4 cyl had burned exhaust valves (1 each cyl). Have a new (remanufactured) head with a little bigger cam in it on the way.

ih8sndq

Awesome, thanks for the follow-up. I'm about to pull the head on mine as well and I will let you guys know what I found.