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Weird Misfire Problem

DamageInc

By DamageInc,
in General Maintenance

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DamageInc Grand Master

DamageInc

Posted
Posted

Mods:

td05-20g

z32

Nistune

Engine:

series 2 rb25det

got my car back from the tuner today , was running sweet as pie , took it for a drive and after about an hour it started to misfire at just over 3,000rpm , first thoughts was a blown cooler pipe as it was when i floored it but that wasnt the problem.

next thing was must be fouled plugs , replaced them with bcpr6es 's and it made it run a BIT better but the problem still existed.

after that i ran the diagnostics on the ECU and it came back with code 43 which is throttle position circuit.

took the throttle body off and cleaned it and also cleaned the TPS to be sure. that did a bit of f**k all ...

next i unplugged it and that didnt change a thing either.

so now , im wondering what it could be

anyone got suggestions?

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Spurdo Experienced

Spurdo

Posted
Posted

so when you say you "replaced" the coils, did you use new coils or 2nd hand ones?

2nd hand coils = complete waste of time. even the "newest" 2nd hand coils are all old and somewhat tired now. dont piss around. buy a new set. any brand, they all seem to deliver excellent results.

DamageInc Grand Master

DamageInc

Posted
  • Author
Posted

so when you say you "replaced" the coils, did you use new coils or 2nd hand ones?

2nd hand coils = complete waste of time. even the "newest" 2nd hand coils are all old and somewhat tired now. dont piss around. buy a new set. any brand, they all seem to deliver excellent results.

well considering i let someone touch my car and wire something up , i dont have the coin to blow on new coilpacks seeing as i just bought a new z32 and 040 and had to pay for them to be installed cause the car was sitting in a workshop.

the problem isnt coilpacks. its something more serious caused from the person wiring the power on the z32 into the signal wire and vice versa.

  • Like 1
PUDZ 32R Enthusiast

PUDZ 32R

Posted
Posted

my bet is still on coil packs breaking down under load. when it is boosting. my '32 was doing the exact same thing when i wound the boost up to 14psi it lasted a few days then started to missfire when it was boosting. drove fine at all other times. i ordered some yellowjackets from performance wise through this forum and now they are fitted my car runs sweet. no missfire no loss of power under boost no overfuelling backfires out the exhaust. all good.

i would suggest winding your boost back down if that fixes it it is definatley coil packs. if you gap your plugs 2 low you will still get missfires due to the spark simply not being strong enough to ignite the fuel. i run mine at .9 with yellowjackets and no issues. the missfire started at .8 with new iridiums and standard packs.

SECURITY Grand Master

SECURITY

Posted
Posted

the best way of testing your coil packs (without actually buying another set) is to keep closing up the gap of your spark plugs. if you've gone .7, try a .6 gap and see what happens. if it still doesnt fix it on .6 then it may be something else.

  • 2 weeks later...
aardi Contributor

aardi

Posted
Posted

Hey just started getting the same problem with my 33 s2 aswell. Took it in for dyno and tune and turned the boost up now it has a really big miss under boost but doesn't have to be alot of boost and it misses. Big miss though. Do you guys think could be the same problem running .8 gap pulled it down to that when i was getting a missfire last year, now the boost back up same thing happening but worse. Did you fix your miss with coil packs mate. Will try the above mentioned fixes and let u know how i go. I also heard that tapping up the coil packs or painting them with clear nail polish to stop any spark leak. Might give that a go too. Let u know how i go cause nothing worse than punching it and getting a huge miss.

Tony de Wonderful Veteran

Tony de Wonderful

Posted
Posted

i ran the diagnostics on the ECU and it came back with code 43 which is throttle position circuit.

anyone got suggestions?

Why is everyone ignoring this key piece of info and jumping to conclusions about coilpacks?!

Looks like a short or disconnect of the TPS or it's wiring/harness.

DamageInc Grand Master

DamageInc

Posted
  • Author
Posted

its nothing to do with the TPS.

the wankers who did my fuel pump used carby hose and a hoseclamp that was too big causing the hose to perish and come off of the pump...

they can expect a phone call first thing tuesday from me.

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