Still Misfiring. Not Plugs, Not Coil Packs, What else?

[AutoTrust]

a dyno tune is cheaper than coils, octane booster doesn't make your coils better.

[red17]

I only just solved a shocking miss and sputtering above 3k rpm that had been getting steadily worse. But it was totally intermittent, the car would drive fine for long periods then just come to a sputtering halt in 30 seconds flat.

Determined to find the problem i changed the plugs, no go

I took it to my local speed shop and they told me i had the wrong plugs in and wrong gap. Stick new ones in... no go

For some reason my suspicion was that it wasnt ignition. Because when i stick it in a high gear at low speed (give it some high ignition load) it would just pull out. Then splutter again at a bout 3200rpm, then pull smooth to redline. Other times it would break down so much it wouldnt pull past 2000rpm.

The solution? Air flow meter. Pull it out and give it a good spraying of contact cleaner. Car now drives better than ever.

Red17

[WLD747]

where can i get a dyno tune done in melbourne. I live on the west side of town. How much are we looking at. Ive heard of BMT being a good place but dont know where they are.

cheers

AK

[AutoTrust]

I am not the best person to answer this queston as I have not had a dyno run with my skyline yet and am south east, I can however recommend Hypertech Autosports

7 Trade Place Vermont VIC 3133 (03) 9874 8866 Ask for Arnold

[WLD747]

anyone thought maybe our 0.8 gapping is wrong.

maybe a 0.7 gapping with timing 15 advanced?

giving it ago let you guys know if it works.

[R31Heaven]

Just out of interest When I started my car this morning when it was cold it started to idle roughly again, so I unpluged the AFM and the revs went up but the car ran beautifuly. whats got me that my Auto elec said they had it tested & calibrated it and it was fine, I have my doubts. now to find a loan one so I can test it...

[red17]

I was also told that my AFM was fine. Nissans ECU diagnostics showed the values were within spec.

But after cleaning the AFM the problem was fixed, so it must be that!

Red17

[Oyabun]

Interesting discussion...

BMT is @ 5 Abbott Street, Fairfield

www.bmtmotorsports.com.au

Cheers,

Oyabun.

[WLD747]

Oyabun, Are you from BMT, if so can i bring my car in for a dyno tune to hopefully fix this problem.

I dont have an aftermarket computer. Can i still get a dyno tune done?

cheers

AK

[NIZR34GTT]

Hi I had the same problem with my R34 it was missing like hell at about 4800 to 5000 revs.I replaced the plugs with Platinum and gapped them at 0.8.

I also suspected one of the coils might have been arking across to the cylinder head as well so I taped the stem of the coil pack with insulation tape,Hey presto going like a train no miss.

Maybe I should take the tape of the packs to see if it gets the miss back.

I had a very similar problem with a Telstra Ghia a few years ago.

So maybe worth a try.

[WLD747]

anyone got any fixes yet?

ive got platinums in my car gapped at 0.8 so hasnt fixed my prob. Gona give the afm plug a go tomorrow.

Cheers

AK

[Guest Robo's]

WLD747

I had similar problems too you, changed and gapped plugs numerous times, coil packs checked, AFM, then raised the boost and it made it worse, backed it back and it was better. Then installed and dynoed tuned with a SAFC and fixed it. Basically for my car, it was getting to much fuel to drink. Are your plugs black?

And whilst not only fixing the problem, i scored some nice power gains.

I will be doing some further tuning soon.

http://www.skylinesaustralia.com/forums/sh...&threadid=22703

[WLD747]

Robo's - thanks for the advise cause im getting a PFC asap which will enable me to tune my afr. I found out today from another mechanic that my car is extremely rich so yeh hopefully problem will disapear soon.

I recommend to anyone with mild mods to get a new ECU or a SAFC to balance the ECU. Because it makes sense. 1 -4RPM not much fuel so boost quick and hard then 4PRM + too much fuel and boogs down.

Thanks in advance Rob

AK