R34 25 N/a Engine Light + Misfires. Only At Idle / Up To 2000Rpm?

[flashy]

G'day guys. Below is a summary I've written up of whats happened. Bought the car from a dealer in melbourne, drove it back to sydney without issue, drove it around for a month with no issue, then;

Engine light on. Intermittently on/off for 1 week, now constant.First few engine lights did not produce any symptoms, just the light. After the light stayed on for 2trips, afterengine was warm misfires started. Car has not been driven since.

Started today and let idle til warm. No issues when starting except for a shortsqueal when first started, once it's warm though:

Bad, constant misfire at idle.

After launch / revs it misfires through til 2000RPM

Between 1000-2000RPM dramatic power loss. After 2000RPM power is almost normal. Smallloss though.

If turned off once warm and attempt to start again, the enginewill start and immediately cut out. Itwill stay on if revs are applied while starting. Note: this only happens oncewarm, has never once failed to start when cold.

Consult port shorted for reading: Gave error code 21 consistentlyover 3 tries (diff. days)

After researching here and other places (Dr. Google!) these are my thoughts, in order:

- Coil Packs and / or spark plugs.

- TPS

- MAF

- Water temp. sensor.

Booked in with the mechanics on wednesday but would love to not have to spend the hundreds of dollars if it turns out to be a coil pack or something that I could of replaced myself. Any thoughts?

Cheers!

[Jonno34]

how many kms has it done? mine went for 95,000 when the coil packs messed up, apparently its a common issue for r34s with that many kms

[-Jimmy-]

It's most likely going to be the coilpacks.

Or the other thing which you haven't mentioned would be the AFM.

[photonmoo]

mine sadly is doing something similiar, 118000km on the clock.... I've only had the car for about 10 days though

Check engine light comes on randomly and will stay on for a bit, maybe go away but generally stays. Yesterday though, there was a bit of shaky idling and quite a bit of misfire too

I'm assuming it's the coilpacks, i've literally checked everything else and done my homework. Just have to wait till I can afford another $600 on coilpacks, boo

[photonmoo]

mine sadly is doing something similiar, 118000km on the clock.... I've only had the car for about 10 days though

Check engine light comes on randomly and will stay on for a bit, maybe go away but generally stays. Yesterday though, there was a bit of shaky idling and quite a bit of misfire too

I'm assuming it's the coilpacks, i've literally checked everything else and done my homework. Just have to wait till I can afford another $600 on coilpacks, boo

[Jonno34]

take it to a good mechanic and theyll be able to confirm that for you, i took mine to andrew at hyperdrive malaga and he just plugged his laptop in and confirmed it was a problem with the ignition system before he started work, but im 90% sure itll be coilpacks ... expensive as hell though couldnt drive my car for a few weeks till i had enough $$ to change em

[666DAN]

Search "R34 diagnostic paperclip" should bring up a thread with the instruction on how to pull the error codes.

[666DAN]

Search "R34 diagnostic paperclip" should bring up a thread with the instruction on how to pull the error codes.

[photonmoo]

take it to a good mechanic and theyll be able to confirm that for you, i took mine to andrew at hyperdrive malaga and he just plugged his laptop in and confirmed it was a problem with the ignition system before he started work, but im 90% sure itll be coilpacks ... expensive as hell though couldnt drive my car for a few weeks till i had enough $ to change em

Hmmm, maybe I shouldn't drive the car then? or is it still okay for short trips?

[Jonno34]

depends how bad it is man, mine at first was initially 90% of the time fine, only a few minor shakes, however after a couple of weeks the whole car shook when idling, felt weird to accelerate and sounded horrible 90% of the time so i stopped driving it until it could be fixed

[Grey]

defs coilpacks order some yellow jackets take it apart pop em in problem fixed

change spark plugs while your at it too

[flashy]

Search "R34 diagnostic paperclip" should bring up a thread with the instruction on how to pull the error codes.

Yeah, ref first post when I said i "Shorted the consult port" this was the paperclip method. As mentioned got error code 21 consistently.

defs coilpacks order some yellow jackets take it apart pop em in problem fixed

change spark plugs while your at it too

This is what I'm thinking. Probably order some from performance wise during the week. Only thing I'm unsure about at the moment is whether I should install them myself or not. The N/A how to looks somewhat complex removing all the hoses and intake manifold :S

Also semi-mechanically retarded, however I've always been meaning to learn more and this may be a perfect time to?

Got the changing coil packs guide so should be okay... will need to look up how to change the plugs once all is out... I'm assuming you need more than a socket set to get the plugs themselves out lol.

[flashy]

Search "R34 diagnostic paperclip" should bring up a thread with the instruction on how to pull the error codes.

Yeah, ref first post when I said i "Shorted the consult port" this was the paperclip method. As mentioned got error code 21 consistently.

defs coilpacks order some yellow jackets take it apart pop em in problem fixed

change spark plugs while your at it too

This is what I'm thinking. Probably order some from performance wise during the week. Only thing I'm unsure about at the moment is whether I should install them myself or not. The N/A how to looks somewhat complex removing all the hoses and intake manifold :S

Also semi-mechanically retarded, however I've always been meaning to learn more and this may be a perfect time to?

Got the changing coil packs guide so should be okay... will need to look up how to change the plugs once all is out... I'm assuming you need more than a socket set to get the plugs themselves out lol.

[photonmoo]

depends how bad it is man, mine at first was initially 90% of the time fine, only a few minor shakes, however after a couple of weeks the whole car shook when idling, felt weird to accelerate and sounded horrible 90% of the time so i stopped driving it until it could be fixed

defs coilpacks order some yellow jackets take it apart pop em in problem fixed

change spark plugs while your at it too

Yeah, ref first post when I said i "Shorted the consult port" this was the paperclip method. As mentioned got error code 21 consistently.

This is what I'm thinking. Probably order some from performance wise during the week. Only thing I'm unsure about at the moment is whether I should install them myself or not. The N/A how to looks somewhat complex removing all the hoses and intake manifold :S

Also semi-mechanically retarded, however I've always been meaning to learn more and this may be a perfect time to?

Got the changing coil packs guide so should be okay... will need to look up how to change the plugs once all is out... I'm assuming you need more than a socket set to get the plugs themselves out lol.

I'll try the paper clip method and see what it says, but i'm pretty certain its the coil packs. Will have to go with the yellow jackets for now, as it's a bit cheaper, might as well change over the spark plugs too while I'm at it, there is another $120 :S

Thanks for the info guys, and sorry for me semi hijacking the thread

[nosking_178]

hey, it sounds like you have a dodgy ignition amplifier within the coil pack.

my suggestion is to run the car without the coil pack cover temporary and then with the engine running unplug one by one. to diagnose which cyc is misfiring.

if you unplug it and the engine changes then that coil pack/cyc is still good. keep doing that to all 6 cyc until you notice the one when you unplug does not changes >>means that cyc isn't firing (hope that makes sense)

once you do that... you know its that cyc thats misfiring. so its either most likely the injector or coil pack (90% of the time its coil packs).

to narrow it down 100% its the coil pack that is playing up you swap the coil pack from the cylinder that isnt firing with another cylinder that is firing.

and last of all once swapped, you unplug the coil packs you have just swapped over and see if the problem has moved onto the cylinder you have just swapped.

and because it does it only when its warm... you may be able to get away by insulating it with tape or other stuff sau members have recommended. if that doesn't work buy a replacement coil pack.

hope that helps!!! just from my experience of misfire its a headache!

goodluck

chris

[nosking_178]

hey, it sounds like you have a dodgy ignition amplifier within the coil pack.

my suggestion is to run the car without the coil pack cover temporary and then with the engine running unplug one by one. to diagnose which cyc is misfiring.

if you unplug it and the engine changes then that coil pack/cyc is still good. keep doing that to all 6 cyc until you notice the one when you unplug does not changes >>means that cyc isn't firing (hope that makes sense)

once you do that... you know its that cyc thats misfiring. so its either most likely the injector or coil pack (90% of the time its coil packs).

to narrow it down 100% its the coil pack that is playing up you swap the coil pack from the cylinder that isnt firing with another cylinder that is firing.

and last of all once swapped, you unplug the coil packs you have just swapped over and see if the problem has moved onto the cylinder you have just swapped, if it has moved onto the cyc you swapped then you know its def the coil pack that is dead/playing up

and because it does it only when its warm... you may be able to get away by insulating it with tape or other stuff sau members have recommended. if that doesn't work buy a replacement coil pack

hope that helps!!! just from my experience of misfire its a headache!

goodluck

chris

[shanedon90]

Is there anything to do with the gap of the spark plug for the misfire.? (if there's more gap, more likely to misfire.?)

[Moodles2]

It's a double edged sword, reduce the gap to reduce a misfire, but at the same time lose alittle power as well. You generally start at the default gap (1.1mm) and gap it down until the misfire goes away (usually 0.8mm)

[flashy]

If anyone is interested or having similar issues, following advice here and elsewhere I bought and installed 6 new yellowjackets which fixed the mis-fire straight away and improved performance a teency little bit. Haven't had any issues since.