1993 Accord LX - 252,000 miles recent head job (cracked head). Car ran fine for month until what seems like ignition issue. Car will start and run good for first moments, then irratic idle. If cold or warm, car seems to miss immediately when put in gear. The miss will come and go both at idle and at drive speeds. Put car in park, idles good then not so good, on and off. A friend also has 1993 accord which runs good. Swapped the coil to check, but no change. The irratic nature of the issue is puzzling. Any ideas? Thanks!

 

I moved your posts to get more focus on your problem and not mix w/ other posters problem. Suggest you edit your title.

First question. Is check engine light ever on? If yes, access code and repost.

Second question: How long since a tuneup; plugs, wires, distributor cap, rotor?

Third question: Are you losing any coolant? Check exhaust for white smoke (steam). This would indicate a failed head gasket.

good luck

 

Thanks! CEL never been on! New Plugs, dist cap and rotor with new head. Wires couple years old. Coolant level been great since head replaced. Checked for bad plug wires at night but saw nothing.

 

Maybe clean the EGR ports? Search online for a procedure.

 

Thanks PAHonda. I cleaned all ports throughout the intake system. Used several can of cleaner cleaning the EGR ports, EGR valve, throttle itself while waiting on my replacement head. Think I'll go ahead and replace the wires, which I probably should have done anyway. Could a plug foul or a dist cap or rotor fail such that it fires intermittently? Can fuel pressure regulator or injector fail intermittently? I'll have time this weekend to do more thorough check. Any additional direction would be helpful. Thanks to all!

 

As an experiment, disable the EGR by removing the vacuum line to the EGR. Plug end of vacuum line. If this stops the missing, it suggests possible EGR valve problem (EGR sticking open slightly). This seems not very likely, but worth a check since it's easy to do.

A cracked rotor or distiributor cap usually results in a dead (continuous) miss, but a random miss might be possible. Suggest a careful inspection of rotor and cap for any hairline cracks.

Another possibility would be an intermittent coil. This happens but is rare and should get worse as car warms. I believe your model has an external coil. If you have a timing light, attach the inductive pickup to the coil output lead and watch for flashes w/ the engine idling. If you see "gaps" in the flash sequence, the coil may be the problem. It's also possible the ignitor could disable the firing intermittently, but this seems less likely than the coil.

I seriously doubt that fuel injectors or fuel injection timing is an issue. It's certainly possible to have an intermittent fuel injector, but I've never heard of this happening, so it must be rare. Perhaps a fuel injector cleaner might help.

good luck

 

Ok... pulled plugs and appeared ok (only 2000 miles). The upper end #2 cylinder plug was wet. Didn't look like antifreeze. Looking into cylinders, #2 appeared moist. Checked oil, it was gray? Did not have chocolate milk look. Cleaned plugs idle much better until warm... same problem. Bought new plugs, idle is good. Drove 17 miles, all ok... for now. Changed oil and looked for antifreeze when first draining. Saw none. Pulled plugs after drive. #2 cylinder was blackened at base, the others fine. #2 cylinder did not appear moist.

I may have used too much antisieze when plugs installed, finally causing plug to foul? Would misfire cause gray oil (unburned gas?)??

Jury still out. Will drive and monitor day to day.

 

If you can have someone or yourself watch the exhaust as you drive after fully warming. If HG leak into cylinder, you should see some bright white smoke, at least until it starts missing.

Possible missing is due to excessive fuel, but hard to see how this could happen on one cylinder. Check oring seat of fuel injector to be sure it's fully seated, although a leak would presumably lean the mixture not enrichen.

Watch your coolant level closely. If you're losing coolant, it's either a head gasket or external leak.

good luck

 

Thanks for your and PAHonda's interest! Well... didn't get 6 miles to work before miss started again! I am starting to suspect a bad head or possibly bad ring.

I didn't think these two are related, but beginning to think so now. Since installing the head, car has used about a qt of oil a week. Suspected it leaking externally. Finally got a chance to investigate and sure enough, saw oil running down the oil filter mounting off the block. Replaced the oil pressure switch and oil run stopped. Figured I licked that problem. But after another week (when the miss cropped up), oil was again a qt low. (My daughter drives the car and away in college, so very difficult to get hold of to do diagnostic work). I kept thinking if burning that much oil, surely would foul plug. Now... maybe I'm there??

I did compression check two nights ago and checked #1 to #4 183, 183, 180, 187 (before head work, 178, 138-cracked head across exhaust valve to coolant port, 178, 181. Interesting that before head work it was #2 cylinder with issue). Again, cylinder #2 looked like it had moisture on the piston. Last night after my 17 miles drive on new plugs, the piston looked dry. I know if you put oil in cylinder, compression will jump if rings bad. I wonder if my compression check with damp looking cylinder artifically inflated my compression reading. I probably should replace the plug misfiring, thinking it is #2 cylinder, and drive ensuring a dry piston and do a second compression check to verify. If compression still ok, I suspect a faulty head may be culprit? If so, valve guide/seal started bad and got worse, maybe at last fouling a plug, but why no smoke?? If compression down, ring problem?

To answer your question, I have check for smoke while looking for oil usage, saw none. Check for smoke puff when cranking cold... saw none. Checked radiator for bubbles when cranking.. saw none. I have not inspected the fuel system. Currently, after now 7+ weeks of use, have yet to add coolant. Level maintaining well and system is pressurizing. Your thoughts?

 

Is the part of #2 spark plug that connects to the spark plug wire wet with oil?

Did you do the work replacing the cylinder head?