No luck with misfire... >:(

[monkeydude3]

Okay... 1990 Accord LX, 4 Door automatic. SOHC 2.2L. 220000 miles

Problem is this. On a cold startup, sometimes it takes a fair amount of cranking, a lil sputtering and then she fires right up. Runs absolutely as fine as a cold engine can, no misses, no stumblin, nothin. As it warms up, it gets a misfire at about 1500 rpm when under light throttle and load.

It has new spark plugs and wires 2500 miles ago. I had a look at the cap/rotor and they appeared to be newer, and there was no carbon tracking I could see inside and all the electrical tips were just a little darkened, nothing too bad.

Has anyone encountered this problem? I have looked over all my vacuum lines again and again and have found no leaks. I believe this engine does NOT use a MAF... so a vacuum leak in my mind would just cause a high idle, if that was the case.

Could my cap/rotor indeed be starting to go (again) and I just can't see it?

I was thinking about replacing the fuel filter and seafoaming the engine/fuel system. Has anyone done this on this car? How would you reccomend I seafoam this particular car/engine? I've done it before, just not on a CB7. Also, forgive me, but WHERE is the fuel filter on this car and should it require any special tool to remove/install?

I have a feeling that as the car warms up, the injectors are gummed up such that they can spray lots of fuel (cold start and cold running) but can't meter it smoothly under light throttle with load.

I'm really confused with this, and it's getting worse as each day goes by, not drastically, but steadily. The thing is, 1500rpm is a commonly used rpm for me as in going through a parking lot or a gentle cruise, so the misfire gives the car a nice shake almost all the time. If I go WOT... no problems.

The kicker is the misfire is only under specific conditions, so I have no CEL at the moment.

Any ideas, any input, let me know... I know this thing has a lot of miles on it but I know the problem at hand can be fixed I just need some help.

thanks!!!

George

[NAiL05]

SO when you do get your CEL what does it throw? As for your rotor already darkening that could cause some of it just clean it off and see if it helps or kinda sand a bit of it off so the contacts are clean and see if that kinda removes the miss.

[asleepz]

I think he is stating he hasn't got a CEL yet. He's waiting for one lol

Man that's a wierd problem. Go ahead and put some seafoam in the gas and suck it through a vaccume line. Mine takes it real well, but my god does it smoke!

[monkeydude3]

Yeah, the last time I had a CEL it was for the bad VSS. It has not set a CEL with the misfire yet.

Okay, I was gonna pick up a can of seafoam today. I am probably NOT gonna run it through the oil on this one, cuz it's high milage, so I'll put 1/2 can in the vacuum line, let it stall, then dump the rest in the fuel tank. Let it sit 10 mins and then run it. We'll see, it's very odd.

I have no idea what would cause this...

Thanks for the help guys, appreciate it! Keep it comin

I did clean the contacts on the cap/rotor, made NO difference.


George

[wnt_2b_boosted]

I had the same problem

my cb7 still hesitates on idle but just a tiny bit and use to mis when i gave it light throttle under load. changed out fuel filter plugs wires all that good stuff no help. So i ended up taking off th IM and all sensors connected including TB and Plenum cleaned everything even scrubbed the ports on the im with a toothbrush, so basically every compenent to the intake was cleaned, bought all new seals and gaskets put back together and missed 1 time and never again sense.

[NAiL05]

You could try cleaning your EGR and see if that kinda helps. If its high mileage have you done other changes like fuel filter and such? I would still do that just because the mileage is up there.

[monkeydude3]

I took the EGR off cleaned it out, and the ports didn't look bad at all.

Umm I haven't done the fuel filter yet.

Like I said... forgive me, but where is it on this car?

I'm gonna go buy some seafoam and a fuel filter today and run the seafoam through the vacuum line/fuel in the next few days and do the filter some time.

I may go through and buy an intake gasket set like you said and go through the top and see what I get.

It's odd, it only does this when it's warm. Cold, doesn't do it.


THanks so much!!!!!!

George

[wnt_2b_boosted]

good luck with that!!!! fuel filter is right under the black box that has vacume lines coming out of it. passenger side on the firewall. do a search and u'll find a DIY

[monkeydude3]

Well, just changed the fuel filter, just seafoamed through the brake booster line and put some in the fuel, took it for a drive and it was al lil better. Still does the misfire on light throttle 1500rpm... i'm gonna let the seafoam get through the injectors after this tank and see what i get... still puzzled


George

[monkeydude3]

well, I drove the car 80 miles since the seafoam. What's startin to tick me off, is that the car runs completely better, except the dang misfire is still there, when warm, 1500 rpm light throttle with load.

I really think it may be the cap/rotor.... but I dunno

oye


George

[monkeydude3]

She's still doin it. I'm at a loss, I know it's something simple but I don't want to go throwing parts at it.

It's odd no one has heard of this before... I seem to always run into problems with my cars no one has seen.

Hmm

George

[monkeydude3]

Well I took the cap and rotor off again, had a closer look at them and they did look pretty bad, so I replaced those. Once again the car runs noticably better in every aspect except the misfire.

I'm sittin at 210 miles since the seafoam treatment, and the seafoam is still in the fuel and I'm at about 1/4 tank of fuel left.

Tryin to research where I can but I can't find anything to help figure out this misfire.

George

[monkeydude3]

I talked to a Honda nut here, and he said it sounds like I may have a dirty/sticky injector. Are there any brands of injector cleaner you guys would reccomend? I'd like to get the best for it and run it through a couple times maybe even give it a double shot at once (when I fill up each time)

Thanks

George

[NAiL05]

Yea I was gonna say since you changed out most of your ignition prob something injector related. I think I used the STP stuff and put in higher octane 89 (mid grade) but in the end i still had to change out my injector since one was just basically screwed to death. Usually your supposed to use one whole deal with each tank of gas if I remember. Havent used them in a while so yea.

[monkeydude3]

Well, if studying to be a technician has tought me anything, one thing is new isn't always good.

So friday I'm gonna pull all four spark plugs and see what the deal is. Replaced them 3000 miles ago at this point. I'll lay them all side by side and see if any look to be a lean or rich cylinder. At the same time I'll inspect each wire and the connections everywhere. I'm also gonna try and remove each injector CONNECTOR and clean the connectors as good as I can.

It's so odd how it only is there when it's warmed up, under exact conditions. Otherwise no problem.

Well after this tank with the seafoam, I'll fill up with cleaner. I've heard Chevron is good stuff. I'm debating between the STP, Chevron and the lucas fuel system treatment (has worked good for me in the past).

Oye

oh yeah, my buddy has the identical car as me but it's 5 speed... his just started doin the same thing.

We'll see what I learn friday


george