strider380

Hey guys I really need help with this one. Several months ago I got my first check engine light ever. Car has 180,000 mi and motor has 200,000. Its a 96 civic ex with a 99 civic ex motor. The check engine light was code 71 which is cylinder 1 misfire. I put a different distributor cap and wires on I had laying around (used but in better shape) and the code went away. Pheww. A month or two later the code came back. I think I put in a new rotor and plugs and the code went away after some time. Just about a week ago the code came back. 71 cylinder 1 misfire. I have a gut feeling that its something in the distributor that keeps getting masked when I mess with the ignition. My distributor does say remanufactured on it. dn't know if thats a clue. Anyways this time I kept driving it hoping it goes away and now it has CEL 71, 72, 73...cylinder 1, 2 and 3 misfire. And for the first time its running like crap, shaking at idle. I cleaned the fuel filter really well and put new plugs in. Nope. I bought a new distributor cap and ohmed out all the wires which are in good shape. nope. I ohmed out the coil and it was fine. Now I have a distributor laying around from a obd2b motor which is slightly different then the one from obd2a in my car. but I tried swapping parts over anyway. I changed the icm which didn't improve anything and made it idle weird, so I changed it back. Even tho the ignition coil tested fine, i still changed it because the contact looked better in the other coil. no improvement. I have a gut feeling what I need to do is put a new distributor in.

So far I changed the plugs a few times. Put in a new rotor and cap. put on different plug wires which didn't do anything (I really don't think its the plug wires). I cleaned the fuel filter to eliminate restriction. I swapped a good icm from an obd2b dizzy. which would have made it run smooth but have weird rpms, and it still ran crappy just had weird rpms. and I swapped the ignition coil which didn't change a thing. they both tested good. Can anyone lend some advice?

Jjbaehr

Check compression, valve clearance, injectors, fuel quality

Former User

More details about this^. How? The fuel filter by the battery?

I have never heard of anyone cleaning their fuel filter. Generally, one just replaces it.

HondaPartsHero

Does the performance get better as the RPMs rise? If it's only bad at idle I'd look to se if you have a bad intake manifold gasket leaking. You can test it with some carb cleaner.

strider380

My girlfriends been telling me to check the compression for two days. shes not much of a mechanic, but is right in most aspects, so I wouldn't be surprised. I'll give it a check. Valve clearance? really? you think that would cause this? I've noticed my motor has been chattering a little bit with its old age. But figured I'd just run it into the ground. And I've filled the tank at a couple different gas stations so I am assuming fuel quality isn't the issue. Never had a problem in my life with bad fuel.

As far as the cleaning the fuel filter, I have gotten my jeeps off the trail by removing the fuel filter and blowing thru it in reverse direction and putting it back in. An air compressor with 120 psi or so will make one of these fuel filters brand new again. Figured it was the same with the civic filter by the battery. I filled it with carb cleaner and blew 100 psi through it 7 or 8 times in the reverse direction of how it operates. The restriction seemed to get be a lot less after doing this. I don't mind buying a new one tho they are cheap. I don't think its the problem however.

The performance does seem to get better as rpms rise. I attributed this to higher rpm's masking a misfiring cylinder. I ceartainly have no problem checking the intake gasket with carb cleaner tho. thats a good idea and i think would explain it.

I'm starting to think in my gut that its the computer tho and not the distributer. All thats left in the distributor is the ckp sensor which would throw a whole different code all together right?

A year ago, my ecu stopped turning on my AC compressor and I had to bypass it with a manual switch. Is this a sign of a slowly failing computer?

Former User

This^ suggests that the fuel filter is okay.

The distributor has three separate sensors - TDC, CKP, CYP. How have you ruled out the coil and ICM?


A bad ECU can prevent the compressor clutch from engaging but not the condenser fan from running. Where did you install the switch?

strider380

I think I ruled out the coil and icm for sure, using others from a known working distributor. As far as the distributor sensors, I thought that those were three names for the same sensor. I know years ago when I had the wrong distributor in, it threw a crank shaft sensor code. And I would think it would throw one again if that were the problem.

I just threw a switch in on the dash for the AC condensor. bypassing the computer. But what I'm getting at is, is it possible my computers slowly failing? First won't turn on AC condensor, then throw cylinder 1 misfire code, now is throwing cylinder 1 through 3 misfire code?

I have a feeling its the computer. Is this possible?

Jjbaehr

You are skipping the basics here, quick compressions test, check for tight exhaust valves , swap injectors, check for power and pulse to the injectors. Super rare to have a computer cause a misfire.

Former User

No. There are three separate distributor sensors.

What specific wires did you splice the switch into?

strider380

Ok I will certainly give it a compression test. Also I will adjust all valves. I guess its about time at 200,000 miles right? Not sure how to check for power and pulse, but I can swap the injectors around. I even have extras laying around if I get new seals. I have been running my car very low on gas lately which is why I was thinking fuel filter. I'm glad that a bad computer is rare.

I did the AC condensor switch a year ago. I got a pinout diagram for the computer and and cut the wire that controlled the AC condensor and ran it to a switch. Its been fine ever since I did it.

strider380

Did some work on the car tonight. First off I snapped 3 wheel studs off removing the wheel to access the crankshaft bolt so thats a great start. I removed my valve cover and attempted my first valve adjustment. Man those spark plug grommets are tough to get all 4 seated correctly again when putting on the valve cover. I should have checked to see if theres a trick. I gave it a compression test and was shocked to find out 30, 150, 120, 120. I'm assuming I screwed up the valve adjustment. Usually I'm pretty good with a feeler gauge on dirt bikes and old jeeps. Anyways, isn't there a way to tell if its bad rings or valves? Pour oil in the spark plug hole and if compression goes up its bad rings?

I checked all the fuel injector wires were firing. I pulled the ecu fuse and now its just throwing cylinder 1 misfire. But thats how its happened in the past until I take it for a good drive. Then it throws more cylinder misfires. I'll try swapping injectors to see if it moves to another cylinder but first I have to try to restore compression. Any words from the wise?

Jjbaehr

30 lbs on cylinder 1?!? That engine is toast, probably a burnt valve or bad rings. Only way to know is to tear it apart. At this point id just find another motor for cheap.

strider380

I wouldn't have a problem putting another motor in it. But do you think I could certainly rule out bad valve adjustment?