Persistant Miss Fire

[R34 -_-]

Last year my car started miss firing so i got it checked out and had all the coils replaced.

A month or two after that one of the coils packed up so i had to replace that, problem solved for the mean time.

Now almost exactly a year later my car is started to miss fire again (not badly) so i put some injector cleaner in the petrol and for a week the car ran normally.

Now its starting to miss fire on and off randomly, Sometimes it just does it at idle and will fire properly as the RPM is increased or sometimes it will miss fire on heavy acceleration like on off on off on off on off really fast, then a few minutes later its back to normal!!!

I have just replaced my spark plugs and fuel filter and swapped out the coil that packed up last time (because i think its a certain spot in the engine bay that gets hotter than the rest) and it ran fine for a day or two.

Now today it seems to be miss firing just like it used to and i am out of ideas!!! the only thing i can say is that the engine light HASN'T come on, last year when it miss fired the light would come on and stay on until the car was turned off.

Also its more likely to miss fire cruising on the open road in 5th gear

Please can someone help me as its using a lot of fuel and makes the car soooooo slow......

Edited December 15, 2010 by R34 -_-

[V28VX37]

Last year my car started miss firing so i got it checked out and had all the coils replaced.

A month or two after that one of the coils packed up so i had to replace that, problem solved for the mean time.

Now almost exactly a year later my car is started to miss fire again (not badly) so i put some injector cleaner in the petrol and for a week the car ran normally.

Now its starting to miss fire on and off randomly, Sometimes it just does it at idle and will fire properly as the RPM is increased or sometimes it will miss fire on heavy acceleration like on off on off on off on off really fast, then a few minutes later its back to normal!!!

I have just replaced my spark plugs and fuel filter and swapped out the coil that packed up last time (because i think its a certain spot in the engine bay that gets hotter than the rest) and it ran fine for a day or two.

Now today it seems to be miss firing just like it used to and i am out of ideas!!! the only thing i can say is that the engine light HASN'T come on, last year when it miss fired the light would come on and stay on until the car was turned off.

Also its more likely to miss fire cruising on the open road in 5th gear

Please can someone help me as its using a lot of fuel and makes the car soooooo slow......

Hey mate I was struggling with this too earlier this year, it was driving me nuts. Try the things listed in this thread: Resolved Misfire In R34 Gtt - Rb25det Neo Checklist and links to other misfire threads

For the high RPM issue check your CAS and make sure it's working properly. For the fuel consumption issue check your O2 sensor. Also check for vacuum leaks, just in case.

Good luck.

[R34 -_-]

As soon as i started my car this afternoon it started miss firing constantly, then when i got in to traffic and started doing the whole stop start thing the car would shake quite badly while idling.

This is really starting to piss me off.

[blk94r33]

Last year my car started miss firing so i got it checked out and had all the coils replaced.

A month or two after that one of the coils packed up so i had to replace that, problem solved for the mean time.

Now almost exactly a year later my car is started to miss fire again (not badly) so i put some injector cleaner in the petrol and for a week the car ran normally.

Now its starting to miss fire on and off randomly, Sometimes it just does it at idle and will fire properly as the RPM is increased or sometimes it will miss fire on heavy acceleration like on off on off on off on off really fast, then a few minutes later its back to normal!!!

I have just replaced my spark plugs and fuel filter and swapped out the coil that packed up last time (because i think its a certain spot in the engine bay that gets hotter than the rest) and it ran fine for a day or two.

Now today it seems to be miss firing just like it used to and i am out of ideas!!! the only thing i can say is that the engine light HASN'T come on, last year when it miss fired the light would come on and stay on until the car was turned off.

Also its more likely to miss fire cruising on the open road in 5th gear

Please can someone help me as its using a lot of fuel and makes the car soooooo slow......

So your saying:

It started missing, you replaced the coil packs and it fixed it.

It started missing again, you replaced one coil and it fixed it.

It started missing again, you put injector cleaner in, it fixed it.

It started missing again, you replaced the plugs, fuel filter and one coil and it fixed it again.

And now it's missing again? For starters, stop walking under ladders with black cats on them carrying mirrors...

1. With the car idling and missing, does spraying A SMALL amount of aerostart in the intake or vac line temporarily stop it?

2. Have you tried taking the coil cover off, and disconnecting them one at a time to find the miss, then moving the suspect coil to see if the miss moves?

3. What fuel do you run the car on?

[R34 -_-]

Yea at the moment its pretty random, its not quite a constant miss fire.

As you probably know apart from the RB26, skyline engines are pretty stupid having the air intake over the engine, which means I cant take it apart and then feel comfortable putting it all back together correctly.

I haven't heard of aerostart?

If i get a mechanic to take it all apart and then play around with the coils, its not quite at the stage where it misses constantly so i have no way to know if I have replaced the right coil or even if it is the coils.

Edited December 16, 2010 by R34 -_-

[ChEwDog]

Did u find out what was wrong with your car?

what fuel do u use?

(and what is the deal with skyline owners that they dont know how to work on there cars...? taking off the intake manifold air tube over the spark plugs....come on.....REALLY!)

goodluck with your dilema.

[GTR-N1]

Ummm...

From your title, I thought at first we were going to read about you taking an AVO against a stalking G/F who thinks you've ditched her for your car !!!!!!!!!!

So let's go through this again...

If you replaced the coilpacks, were they new or second-hand?

Spark plugs are new > but what gap are they?

Fuel filter is new > but how did the old filter look? Was there any water in it? If not sure, fill up with E85 for 1 tank because alcohol absorbs water > check.

Had the injectors cleaned? 98RON fuel being used?

AFM on your car? If so, have you swapped it with someone else's yet?

[Kenna802]

my guess is replace all the coils if one is stuffed and of the same age i would recommend do them all

[Galois]

Did you mean e85 terry? Doesnt he need a retune to run that?

Sorry mate, but to own an interesting car means you're gonna have to get your hands dirty. Getting at the sparkplugs is an extremely easy job in the scope of things, it's not like taking the engine apart or replacing a gearbox. Have a search, there's some good diy's on here. I got the plug change down to abut 45 mins with my brothers incompetent help once, it's not a difficult job.

The other thing is, it's not a great idea to trust your local mechanic with cars like these. Falcodore/camry specialists get easily confused with skylines, regardless of how many they say they've done before. It's a lesson you only need to learn once mate

[blk94r33]

Did you mean e85 terry? Doesnt he need a retune to run that?

Sorry mate, but to own an interesting car means you're gonna have to get your hands dirty. Getting at the sparkplugs is an extremely easy job in the scope of things, it's not like taking the engine apart or replacing a gearbox. Have a search, there's some good diy's on here. I got the plug change down to abut 45 mins with my brothers incompetent help once, it's not a difficult job.

The other thing is, it's not a great idea to trust your local mechanic with cars like these. Falcodore/camry specialists get easily confused with skylines, regardless of how many they say they've done before. It's a lesson you only need to learn once mate

I think he may have meant E10?