s2konroids

Hi guys I have got a problem...yes you guessed it, its that old chestnut...the misfire problem .


I think the problem is related to idle. A scenerio is I start the car up from cold it will rev high about 2k RPM,
the eventually steady at 1k RPM after a minute or so, the car runs fine pulls as strong as ever but when i come to a junction
the revs will dip really low sometime about 400-600rpm feel's like it about to stall then pick up again. The misfire CEL
only seems to come on after a second cycle of starting the car up, it then seems at this point to produce a CEL after the rev's have dipped
low then a minute or so later a misfire code generally any cylinder with a random too. P300 and p30X etc.

I let the car idle for 5mins I'm sure the cooling fans came on at some point and i did it correctly (its hard to
hear the fans as i have the spoon modification to the intake box and it produces a hum at idle)

Normal spirited driving its sweet as a nut no problem with VTEC. And i have obviously reset the ECU to the clear the CEL, I have drove
to work today only came to 2 junction where i stopped but no CEL so far even though the revs dipped, i would of thought
a 20min drive and very short 5min drive would of enabled to ECU to finish learning by now??

I have looked through some threads, I dont know if anyone can help me?, but so far i have done/checked:

* About 3 month ago I cleaned the TB and IAC valve (carb cleaner etc) - dont think its worth checked again.
* I have replaced the MAP sensor for a new one about 9 month ago? - bought at same time as TCT group buy
* I have checked the throttle cable. It is taught about 2-3mm play in it.
* New spark plugs, oil and oil filter were fitted a week ago and checked them.
* Did the "MAP" whack.
* Worth cleaning TPS and intake one???
* Had a quick look didnt see any loose Vac lines.

I'm currently thinking it could be the injectors i did swap the coil packs around but i dont think it made any
difference. But really I think the injectors could be clogged up, but i think they will probably have clean nozzle and some build up around the side.

I think it might be a good idea to replace or get them cleaned/flow tested? - but generally injectors are quite reliable.

I would be greatful for any help/

Thanks in advance.

Aj

P.S - I'm at work ATM but I have some carb cleaner and contact cleaner in the car and socket set and can get out at
dinner time.

Bibbs

I swapped out the injectors for another member before Xmas (he was about 2 miles up the road). We also ran some carb cleaner through the intake too.

I believe his issue went away and didn't come back.

lower

I had similar symptoms. I needed a new engine. Admitedly there was as slight rattle too.

If i were you i'd rule out the new ecu first before pursuing other possible faults.

s2konroids

True, will probably remove the ECU first.

I dont have a rattle.

S2000_FUN

Do you have a missfire in all cyclinders or in some of them?

My guess is
1) Spark plugs
2) Injectors
3) Bad fuel

s2konroids

Hi It was only on cyclinder one, then the next occurence i got misfire on 1,2 and 4 and a random

Cheers

lower

Sorry, that was mean. it was a bit more than a slight rattle.

Jel

If I were you'd I be tempted to take the head off and eyeball what's going on in the cylinders.

As Lower suggested, I got a mystery misfire/CEL attributed to Cyl 2 by my dealer. The engine didnt last more than 6 weeks after that.

As I recall your block has done quite a few miles, tbh the last thing I'd do is start bolting on (unneccesary) 'power' mods - you've been complaining about this since shortly after you bought the car. Why pull the tail on an already angry dog?

Jel

Ok if we're going to qualify failures my 138 in 4th can't have helped.

Armand

Seems Aj and i are in the same boat.

I had a slight misfire on saturday 4k rpm in 6th, felt like a 'burble' is only way i can describe it, but no issues. Drove to work and back yestarday and left the car standing for 20 mins.
Went to move it again and the dreaded CEL was on. I have done the Map whack, but apart from that, and unlike Aj nothing has been changed on the car recently (9 months).

I am going to check the spark plugs, but i am a bit of a car n00b so any advice on spark plug gaps etc would be greatly appreciated. Other than that i wait on Ajs fix with interest.