jerhigdem

alright iam up in arms over this issue. i bought this car for a decent price thinking this was going to be an easy fix. i had read the codes prior to buying it and figured it was somethin simple and i still think it is but iam missing something real simple. it was throwing an egr code plus all the misfire codes so first thing i did was replace the egr valve. they had already done some electrical work to it, minor stuff like plugs, wires, rotor, cap, they ran compression tests and that all came back fine. they adjusted the valves and i also went through the valves a little bit, they said they cleaned the throttle body and after all that it still threw the codes. me and a buddy went through the vacumn lines and found some nicks here and there and fixed. nothing really showed up when we sprayed cleaner around intake. we kept on and on and got it running what we though was a litle better and then we came to the conclusion it had to be something in the fuel line because it would run fine then start to misfire, i drove it 15miles and it ran fine 80 percent of the time, so this all cylinder misfire is intermittent at best i guess. at idle mostly and seems to come out of it on the highway. well tonight i replaced the fuel pump, the fuel injection pressure damper, and the fuel injection pressure regulator and still running the same, iam going to read the codes again tom night to get the exact codes for any body that can help. and its a California car. any tips and advice is greatly appreciated,

origamy

Does it misfire in 2000-3000 rpm range? Is misfire present when EGR valve is disconnected or blocked of? What the code EGR was? Maybe P0401? If so, did you clean up the EGR passages? It should be done before replacing EGR valve, which probably was fine.

jerhigdem

Its really not consistent in its misfire, all random. Not sure with the egr code, iam gonna read them again tonight. I suppose it couldnt hurt to pull the egr valve back off and do some cleaning?

holmesnmanny

Disconnect the egr valve connector. When it throws a code see if the car runs better. If so, then clean up the egr valve AND the ports.

jerhigdem

That didnt do much disconnecting the egr valve.i wouldnt doubt that does need to be cleaned inside of there though. I emailed a honda guy today and he said it could have something to do withthe vtec, this is my first vtec so i dont know much about them. But the misfire is so consistently inconsistent that it just baffles me

MAD_MIKE

If the car has over 100K miles then it probably is the main feed port from the EGR valve.
Pull the upper intake plenum off and clear out the port.
Check the Accord FAQ on how to clean. Might need to replace the plenum gasket, ~$4.

jerhigdem

So i have taken the upper intake off and cleaned out the egr port and cleaned the plenum up real good and it was all nasty as all hell but still has a misfire. Iam going to cut open the cat now and see if thats plugged up a bit. Wondering as well what could or if there is something wrong with the vtec part. Runs great 80% of the time and goes into misfire mode 20% of time. Seem to do it when i get on it a bit

jerhigdem

Drilled the cat out and still an intermittent miss smh

jerhigdem

Think it could be a crankshaft sensor?

holmesnmanny

disconnect the oxyen sensor connector, when it throws a code see if it runs better if it does replace the sensor with a Denso

jerhigdem

Anybody ever had a crankshaft sensor go out? Could this be the problem?

asinclado

I had the same problem with misfiring codes coming back. Only one of the codes went away after doing a tune up, and the rest kept coming back. After reading lots of threads on the problem and even though it check within specs, I suspected the iginition coil to be the issue. Before trying another one, I cleaned and stretched the spring on top of it by about 1/4" (the one that transfers the high voltage to the distributor cap). That took care of all the misfiring codes that kept coming back.

By the way, the car was a 2001 LX with a TEK distributor and 175K miles.

MAD_MIKE

Recheck the valves are adjusted correctly. Just because they 'said' they adjusted them does not mean they did or did it right. Recheck ALL the work that was said to have been done. If you didn't do it, consider it not done, or at least not done properly. What were the numbers for the compression check? If they didn't give them to you, then it didn't happen. Verify yourself.

When you cleaned out the upper plenum did you clean out the port down to the EGR valve as well?

If the CEL is coming on, verify what codes are being set. Write them down, pull the memory fuse to the PCM this will properly clear any stored codes. Go for a drive and recheck for any codes. If the memory is not properly cleared the PCM may not show any new codes and just get hung up on the same, possibly erroneous, codes.

If the crank sensors are fouled with ferrous material or road debris the magnetic pickups will lose resolution.
Verify they are clean and free of junk, as well as the crank sprocket(where the sensors get the signal from).