Put me in the random misfire club. We need our own badge!

My turbo car would often throw p170 and 172 for running rich but now its moved onto the random misfire accompanied by some or all of the cylinders. I am clinching my cheeks in hopes its not valves. Also bumping this thread for future reference. Can someone link the valve check thread?

 

ive got a new reason for you to throw this series of codes. i recently spent an entire year trying to figure out what was wrong with my car. went through all these issues and couldnt find the problem. turns out i had fried the injector driver on cylinder 3. so apparantly if you burn out one injector driver, it WILL still throw a misfire code on all the cylinders.

 

Hey all....my first post......reluctantly joining the misfire club.

Codes: P0300 - P0301 - P0302. Mods: Injen CAI and Tanabe cat back exhaust...both installed about a year ago. FYI - I bought the S used...it was 2 years old with only 2000 miles on it....so it potentially could have sat and had fuel go bad....but it's ran perfect up to now so maybe not?

Anyway...My S started having a rough idle a few weeks back with the onset of some hot weather...mostly with the air on after just warming it up the rpm's would drop to 500-700 and then come back up ...once it runs for 15 minutes or so it seems better but maybe still a little low and rough. It didn't seem to do this with the air off. It also seems to sputter a bit at low rpms but not real noticable....maybe imagination going wild.

Then a couple days ago my CEL comes on along with the VSA light...the VSA went off but CEL did not....VSA comes back on now and then and clears itself.

I bought a reader and pulled the codes....then cleared them and the CEL didn't come right back but I only idled in the garage. Will wait to see if it come back before proceeding further. Doesn't use any oil and it has 53k miles on it now...and the only maintenance it's had is regular oil changes and the new air filter....daily driver.

So if it comes back I'm going to take to the dealer and have em look at it...I hate to do that but it's still under warranty so I feel I should. The info here is great....

Any suggestions beyond what is arleady posted?

 

Well, the CEL light came back....this time it was just the P0302 code plus a P0302 pending. I guess the pending is just repeat of the orinigal...not real sure how that works.

It was fine all the way to work and all the way home...exited the offramp and stopped at the light and it came on. No a/c on today so that has no connection. Idle never dropped below 900-1000 rpms. But the idle still seems a tad rough....no obviuos missfires but still not as smoooth as I recall it being when new.

I noticed not every one is mentioning having the VSA light too...at least one guy I saw did...so I'm wondering if that changes the approach to troubleshooting the problem....my guess is it doesn't.

Anyway i guess the next step is to either swap the # 2 coil with another one I'm nnot getting codes for either the #3 or 4......or I could just take it to the dealership which is what I'm leaning towards...mostly so I got it in and on record as a problme just in case this becomes troublesome to fix.

I'm inclined just to thro in some new plugs too just to rule that out and so I can see what the original plugs look like...never had em out.

 

Okay maybe a couple things someone can advise and clear up for me. Maybe it's wishful thinking but I'm having a hard time correlating a bent valve other valve problem and a intermitent rough idle.....which seems to be associated with my CEL misfire codes.

It seems like this would more likely be caused by the injectors, coils, spark plugs or possibly that map whack thing and other things on this list I read.

I'm still torn beteween troubleshooting this further myself versus just taking it into the dealership. The car is still under warranty but just barley, 53k miles. So it seems to me that I'd want to at least take it to the dealership so that the issue is brought to their attention before the warranty expires. Any thoughts.... anybody??

Bent valves or some other valve problem is scary...it's never been over revved so I don't see this as the possible cause. I do "rail it" on a regualr basis like S2ooonvegas mentions...I'm not just putting my S2000 around. And I have run into the rev limter on occasion....who hasn't... but not hard so that should give an over rev. Never miss shifts or downshift too hard.

 

I went through the same scenario as you and had the same symptoms except to through a monkey wrench in there I have a supercharger.Did all the coil swapping even injector swapping,plugs.Code kept coming back.The older gentleman at the autozone told me to try Lucas upper cylinder lubricant/injector cleaner.I usually don't use additives and consider them snake oil but as a last ditch effort I gave it a try.I immediately noticed the car idled smoother and guess what the code never came back.I started using this stuff in all my cars.Maybe I just had a bad tank of gas or too much ethanol in the mix but hey whatever it worked.Might work for you.

http://www.amazon.com/gp/product/B0006305R...9&creative=9325

 

Thanks for the tip and link archtop....I sort of think the same thing about gas and oil additives...snake oil....never use them. But hey... if it worked for you I'll give it a shot...same car and same year....it surely can't hurt and it only cost $5 bones or so.

I read the reviews on Amazon and they were all positve...one even said it was better than Seafoam which I seem to remember being mentioned in this thread somehwere. Another one was from a guy that worked at an auto parts store and said it flew off the shelves when it was on sale...somthing the other brands didn't do. So it seems like some genuine good reviews.

I'm curious... how do you like your supercharger? Did you ever go to the dealership with your's for the problem or just do the troubleshooting yourself?

 

I have the KW high boost setup with just the Hondata reflash and I absolutely love it.I've driven a couple of Comptech and Vortech setups and they just did nothing for my taste.A shop in Atlanta had installed a KW setup on the owners car and he let me drive it,I was sold.Best mod I ever could have done,no real problems in 2 years.Only thing ever was this stupid misfire code/rough idle and now the car runs better than ever...go figure? Just keep in mind that the investment of a supercharger will not come back so only do it if you plan to keep the car for a long time or else you'll have to remove it and sell it separately (PITA)!
I never went to the dealership cause I knew they would blame the issue on the supercharger plus the dealerships suck period...I only go there as a last resort.In my almost 5 years of ownership I have been able to solve any issues myself ( why I love Honda's).I really do like the Lucas snake oil stuff though,I buy it buy the gallon and use the little 5 ounce bottle to put the stuff in my cars.

 

Well I picked some Lucas today after work and put it in with a fill up. So we'll see if it helps...I'm hopeful. I go thru a tankful of gas a week. I reset the CEL light once before and it came back after a trip to work and then I reset again this morning and it didn't come back after the same trip to and from work...picked up the Lucas anyway. So the light not coming back on right away each time sort of makes me think it's not too serious of a misfire and the Lucas might just do the trick.

I too distrust dealerships and hope I don't have to take mine there ever. I've Got a 2001 Honda RC51 motorcycle and it's never been wrenched on by anyone but myself.

Thanks for the info on your supercharger too...I know it's off subject but I was pleased to hear you had the Kraftwerks high boost kit cause I'd been drooling all over their web site...they seemed like the kit to have. It won't be right away but I'm sold on getting the KW high boost kit as well. So you had to upgrade the clutch?

And yes I do plan on keeping my S forever...it's a Honda. I'm a long time Honda fan....ever since my brother used to have a 1968 Honda S800 coupe back in the early 70's...and yes I got to drive it. It's the only one I've ever seen. I always told my brother he HAD to sell it to me....when he traded it without telling me I was pissed. When Honda came out with the S2000 I knew I had to have one.....it took me awhile to get one... but now my brother is jealous of me.

 

Okay an update:
The CEL light has came back on two more times now and each time it has been only the P0302 or that one and the P0301....the Random misfire only showed up the first time the CEL light came on. The idle seems better after putting the Lucas stuff in it...in fact it doesn't seem rough at all with no a/c on...looking at the engine while at idle it's dead smooth.... almost could do the balanced nickle trick. But it's been a tank and half now and the lights still coming back...worth the try but time to try something else. Also no abnormal noises from the motor no ticking or clicking...i would think if you've got a bent valve it wouldn't sound good.

So since it's only shown the 301 and 302 I swapped coils...the #2 with # 3 and #1 with #4. Started it up and no light...but it's alway taken a couple drives for it to come back...and I expect it to come back. But I'm hoping it comes back and throws 303 and 304..... although for some reason that doesn't seem likely.

So with all that being said does the fact that it always has at least the 302 code..... would that steer me to a particular root cause? Any thoughts?

I'm inclined to next put new plugs in this weekend if the problem doesn't move with the coils. By the way while I had the coils off I checked to make sure the plugs were tight and they were. I didn't want to pull them unless I have new ones in hand. I know I'm supposed to be doing a compression test...I'm just too darn afraid to yet....Maybe I do a vlave adjustment next....hasn't been done ever yet so it couldn't hurt.

Makes me yearn for the days when my brother had his S800 and it's old style coil, no ECU and a real carberator....anyone got a '67 or '68 S800 in mint shape and want to trade straight up? Not holding my breath.