misfiring BAD......

[datsunboy]

Hey guys, my car has been running well up untill a few days ago.

now it only boosts up to about 3psi ( because its missing so bad ).

it only really starts to miss when boost comes on.

and sometimes it almost dies completely......and you have to shut it down, then re-start it.

so Im thinking its not a boost leak problem, considering it dies completely sometimes.and maybe either a coilpack or Ignitor problem?

has anyone had similar problems before?
Modified by datsunboy at 6:07 PM 4/25/2006

[pulsar gtr]

If you have a severe boost leak it could cause the car to die, so, to be on the safe side, check your intercooler pipings to make sure there is no leak, if not, yes, the ignitor definitely can do it. I don't think it is a coil pack, as if only one coil back goes bad, you should be still able to boost over 3 PSI.

Good luck,

RafiPULSAR GTR

[Coldspawn]

What are the specs on the car?

[datsunboy]

pretty sure it wont be a boost leak, but I will check anyway.I'll also check the Ignitor, as that does sound most responsible!ECU gave code 55.

specs:700HP NOS fuel pump450 VR4 injVR4 FMICZ32 MAFGTiR T28 turbofull 3" exhaust

[rico05]

Sounds like a bad coil. Get the car running, and pull each plug off of each coil one at a time. If you pull one off, and it gets worse, that coil is ok. If you pull one off and it runs the same, then you have a bad one.

[float_6969]

Boost/Vac leak (though it'd run crappy all the time) or bad ignitor/coil pack (more likely). You can try pulling plugs off the car while it's idling, but if it seems to idle OK, you may not drop a cylinder.

[datsunboy]

yeah.....it doesnt have problems unless under load with boost......so pulling plugs at idle isnt going to help.

I forgot to mention that it has RB20DET coil packs on it.....but they've been on there almost as long as I've had the car running.

I have replaced a dead ignitor ( with another CA18 one ) at one stage about 6months back too.I have been having problems with my alarm going off as soon as I trun the key off sometimes......so everyso often, I will leave the key ON with the engine off ( I know this isnt meant to be good for the Ignitor ).

And also, when trying to run my ECU off the laptop and emulator, it would keep clicking the fuel pump on and off really fast......which could have screwed something eventually. ( I fixed that problem by added a ground strap from the laptop to the ECU......fixed it )

[TurboFortysx]

Have you had it tuned recently? It could be pig rich.

[datsunboy]

no it hasnt been tuned.....but it has been on the DYNO, and it is running pig rich......but its been running like that since it was first run and has been fine up untill now

[datsunboy]

ok......havent played with it yet......but took it for a drive, and recorded a audio clip to help you guys know what Im on about....

foot is flat when it's missing......then about 4sec into the clip, I change to 2nd

[datsunboy]

boost.amrit should work with windows media player......but if not, nokia media player works with it....and is free to download

[datsunboy]

bump

[float_6969]

I think you burnt up an ignitor. Running rich puts A LOT of load on the ignition system. Get it leaned out, clean/replace the spark plugs, and see how it does.

[float_6969]

Well I listened to the audio clip, and it's hard to tell, but it almost sounds more like a fuel cut or something.

[datsunboy]

yeah, it is cutting out completely when it does misfire.....It still drives for the moment, and I need to drive it on sunday (wont be driving it before then), after then I'll start dismanltling bits like that and testing them out.

[NismoBgt]

I had the same trouble when I put my engine in. It turned out to be a combination of things. The timing belt was worn and and hoped 2 teeth so the exhaust timing was off, also the ignitor was lossing one channel and was intermitent. I had ended up going thru several items like a TPS, O2 sensor, AFM, water temp, an ECU, and a set of plugs before I found those two items.