anthon_E

I know some of you are thinking "Here we go again" but I need help here.

Yesterday I changed the spark plugs to NGK pfr7g 11s.

When changing them out, the spark plug that came out of cylinder 1 had all this black soot on it. I was told that it was from fuel not being ignited, therefore giving me the misfires codes. The other plugs looked pretty normal, no black soot kinda light brownish/orangish i think.

Cleared the codes and took a drive, no CEL.

Turned on the car again and what to you know, CEL. Misfires on cylinders 1 and 4. Looked at a snapshot/freeze data (?, forget what it's called) on the reader and it said the misfires happened at 780rpm. Didn't clear the codes. Drove around a bit.

Moved the coil packs around to different cylinders, checked the codes to see if any changes while driving earlier, misfires of all 4 cylinders, and cleared the codes. Took a drive and it popped up again.

Car sat around for a good hour and 1/2, start it up and WHAT NO CEL!!! Happy at this point.

But driving later on and it came up again.

Should I change the coil packs (which was recommened)? They looked fine when we pulled them out, by definition of fine, I mean they didn't look beat up or had any residue on them inside and out.

What should I change/do?

WalkingDrunken

Did you only try one set of plugs? maybe you should try a second and possibly a third just to be possitive. I mean it is a heck of a lot cheaper.

Also double check the connections from the wiring harness.

I'm not good with names of tools but I know there is a tool that you could use to check your coil pack to make sure that it is sparking. I have seen a couple different ones, one with almost like a light bulb and others that ground out the spark plugs so you actually see the spark.

but you can do that kind of test on your own by grounding it out. Make sure it's grounded otherwise you'll get a nice shock.

WalkingDrunken

The "black soot" is nothing to worry about. Unless it is A LOT. It would be easier to diagnose if you could post pictures up of them.

Have you tried to reset the ECU instead of just clearing the codes? Might not do anything but it's so simple why not try.

anthon_E

walkingdrunken thanks!!

i only tried one set of plugs, brand new from the dealership.

i'll talk to my friend about the tool you mentioned, he works at a toyota dealership so i think they should have it there.

i have a pic of the dirty spark plug, but i can't get my phone to send it to my e-mail. i'll post it later on tonight.

i'll try resetting the ecu right now. i'll post results later.

anthon_E

here's the crappy cell phone pic:

anthon_E

i realized in my first post that i didn't mention i had a multiple misfire CEL before i changed the plugs, that's the whole reason why i changed them. hopefully this clears some things up for some people.

anthon_E

So I reset the ECU yesterday. Drove around for 30 min without the CEL coming back up. Then, my second start up it came on.

Today I did a compression check. Cylinder 1 put out 140 and the rest put out 180.

When the spark plugs were taken out, the cylinder 1 plug was darker then rest. Not as dark as the pic above though.

As a test we put the No. 1 plug in cylinder 4 and the No. 1 coilpack on cylinder 3.

Gonna check them out tomorrow to see what's up.

Billman250

Resetting the ECU will accomplish nothing.

Looks to me you have incomplete combustion, due to low compression on cyl#1. The code for #4 is likely a false code.

Personally, I'd pull the valve cover and look for a tight valve on cyl 1.

anthon_E

thanks billman!!!

i'll take it down to honda to get the valves checked. hopefully everything is in good condition.

do you know how much it will cost at the dealership to check the valves?

Billman250

Not sure, prolly a few hrs. Make sure you tell them you're looking for a tight valve. Ask them to set them at .008 on the intake and .010 on the exhaust. 98% of s2k's come loose from the factory, usually around .010 and .012. This will not cause your problem, but tight valves will.