20s2k03

I posted a couple of weeks ago about a #4 random misfire code with CEL and rough idle. After new plugs and sea foam in the gas tank the car has done great, even on a 600 mile round trip...untill last night. After normal driving around for a bit, I came to a stop and the car started doing its all-too-familar rough idle/tick tick tick noise....then the dreaded CEL flash.....I was so close to home that I...kept driving it. The light stopped flashing but stayed illuminated and the car drove normally once it stopped flashing. I turned the car off in the garage and then restarted it....no light.....tried again....no light. I have not lost ANY oil, however upon checking the spark plugs this morning the brand new #4 plug looks dark, carbon-ish.....the hole seemed a bit dirty, but nothing drastic. The other plugs looked fine. I decided to drive it around a bit to get some gas and try and get any codes out of it from the guys at the parts store....it drove fine and no codes were recovered. I did not reset the ECU. I'm planning on driving about 1800 miles to California next week, assuming the appointment scheduled with Honda Monday morning goes well....but since it seems to be driving fine I may cancel.....any clue as to what may cause this come and go problem? I'm more concerned about the spark plug being so nasty after only a couple of weeks....

F20_C

You could have a bad coil pack on the #4 cylinder, just an idea.

heresnowhy

I would switch injectors around and see if the problem goes with the injector....I would guess and injector from the countless times I have seen this issue and the rememdy.

20s2k03

I'm going to see what Honda has to say...I'm leaning towards injectors myself. The thing is, it's so random, I drove it around tonight with ZERO problems.....got on the highway (Vtec'd a bit) then cruised around the city.....acted like the car is new. I'm not burning/losing any oil and my mpg is better then I could've hoped for....27+ mpg. Would a bad injector cause the #4 plug to get so dirty so fast?

20s2k03

FYI the compression and leak checks both checked out fine. Compression is about 220 on all. Dealer suggested new coil packs as the "s2000 mechanic" said he's seen a couple similar problems and one pack can bounce the problem to another or something to that effect. At 120 bucks a piece, I'm lucking out by having Carmax pay for them. I'm gonna add some Chevron fuel inject. cleaner stuff to it too just to be safe......Hope it goes smooth on this 1800 mile trip tomorow.....

20s2k03

UPDATE.....Got all the way to the Cali border and came upon a pretty nasty car wreck so everything was down to one lane and almost at a standstill. Upon slowing down the car started to idle a bit rough and "the TICK" came back.....did not get a CEL*edit* NOW HAVE A SOLID CEL (not flashing) don't have codes yet but I have to get to the base tomorow and go from there* and the car seemed to drive ok when I got back up to cruising speeds but I pulled over and called it a night. The car was still making the noise when I parked and listened to it. It's not the normal valvetrain noise as I can hear it with the windows down and idling and I can almost count the ticks. They follow the rpm's but stay about the same volume so once the rpm's get higher it's harder to hear. I am thinking I may have a bad injector but perhaps it's the sudden changed in climate? Maybe reset ECU and/or MAP whack??
Please help as I am about an hour away from where I need to be and only have till Saturday intill my "30 day warranty" runs out. F Carmax.

Also, noticed my VTEC is engaging late....around 6300-6500....This started occuring well before "the TICK" started but could it be related? I checked the oil and topped it off but it continued to engage late.

PS Lake Tahoe is amazing, everyone should experience it.

update (again): Thankfully, there is a Chevron across the street so I put in some fuel injector cleaner in it then got on the highway and ran the hell out of it. The tick stopped....CEL still on. Should I reset the ECU or get the code pulled first? This car not working right crap is getting old....

20s2k03

Code is P0304