Hi all. I have a 1995 Accord LX 2.2 non VTEC wagon with an issue I can't pin down. When you start up, all is well. After a couple of minutes driving, you can feel a misfire and the CEL comes on. After stopping, and retrieving codes, I just get a solid CEL light. After it is warm, every time you start it and let idle come down to normal the misfire happens at around 1500 RPM whether you are moving or not. The CEL comes on and then you can not take the RPM above 3000. Here is what I've done so far:

There was oil in the spark plug wells, so I changed the valve cover gasket and put in new NKG plugs.

Checked the timing because I had a loose crank shaft pulley recently. It was dead on.

Cleaned out the EGR valve. It was awful and I thought that might be it but it still happens.

I can't find any vacuum leaks or frayed wires. I feel like I'm missing something simple but can't seem to find it. I could change distributor cap and spark plug wires but the symptoms are so specific, that I was hoping someone else might have seen this. I couldn't find any thread that had this specific repeatable series of events. Has anyone seen this before?

Thanks.

 

CEL turning on, then not giving a code would have me leaning towards an ECU issue. Check that the 7.5 amp backup/radio fuse is not blown in the engine bay fuse box. Check the ECU fuse too.

Does the D4 light flash any codes when you short that connector? Or do you have a manual transmission accord?

 

Do you have a timing light? I use them to track down misfires.When I have an engine that misses,I hook up the timing lead to one wire at a time,until I can see a difference in the flashes or pauses in the timing light.It has never failed me once.

Anyways it sounds like your engine starts to miss after it warms up,meaning that on start up,the engine is running in warm up mode,or open loop,ignoring the 02 sensors and etc.In closed loop,look for bad wires,vacuum leaks etc first.

 

Quick update here. I still have not resolved the problem but have narrowed it down a bit more. After changing spark plug wires and O2 sensor, still no luck. I did reduce the probability that it is the ECU by inducing a couple of codes by pulling connections and seeing the correct code blink when jumping the connector. The most promising lead has been the idle air control valve. This only happens when then engine gets warm enough for the IACV to kick in so I thought that must be it. I removed it and cleaned it which actually made the problem worse. I bought a used IACV and just now put it in. Still having the same issue. I can't find any vacuum leaks or wiring issues but because it seems to sync so well with the IACV kicking in, am going to look again in that area.

 

You cleaned the egr valve but did you clean the egr chamber? It is the "plate" thing on the intake under/behind the injectors.

 

Thanks for all the help on this one. In response to the last post, yes I did clean the EGR chamber as well. After all of the fixes and cleaning, it turned out to be a faulty ECU. I thought about this early on but moved it down the list of likely problems because I could induce an error and get the right codes by unplugging the O2 sensor. I ended up taking it to a local garage and they connected directly to the ECU and were getting dozens of codes. Unfortunately, the parts are hard to find so they did not fix it there. I found a used on on ebay for $50 and was able to install it in about 15 minutes. Problem fixed. For anyone else chasing down similar issues, the mechanic said if it was not the ECU, he'd suspect the distributor. This was a nightmare to resolve but after all the work I've put into it, it is running great now.

 

Thanks for the follow up.....too many times we never know the end of the story.