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Running Rich / Massive Misfiring

ZILR-34

By ZILR-34,
in Engines & Forced Induction

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ZILR-34 Experienced

ZILR-34

Posted
Posted

hey guys

i have a R32 gts-t and its doing my head in. the car is runing so rich when i rev it pass 2700rpm it stalls from too much fuel. its blowing so much black smoke and lots backfiring. it started this about a 3days ago as i was driving in the city and it stalled, tryed to start it and no good. after waiting about 5mins it started. so when i got home i pulled out the spark plugs and they were black and smelt on fuel. after replacing them it did the same thing. i have made up a list what you guys think is worng????

Fuel Pump? which is 6months old bosch 040

Fuel pressure? its jumping from 20-40psi

Leaking/blocked injetors? have got them cleaned 2months ago

FPR? Brand new Sard

AFM (z32)? brand f**king new

cooler piping/boost leak? have checked all good

idle / temp sensor? how do i check?

sparkies? replaced

igintor? how do i check

coilpacks? got Splitfires

blowing gaskets? rebuildt head 3months ago

fcked pistons / bad comp? havnt checked

timiing? remaped ecu

o2 sensor? 1year old

turbo? 1 year old GCG highflow

cheers

bill

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Guilt-Toy Grand Master

Guilt-Toy

Posted
Posted

PEBA&TB

Problem exists between airflow meter and throttle body.

You have a leak. best way to fix it is to remove the WHOLE system and re-install it and replace worn parts. boost leak or cooler leak or pipe leak or a silicon hose is broken.

or all of the above. make sure AFM has a good connection.

The Dan Grand Master

The Dan

Posted
Posted
also the car's idle is jumping from 1k to 2000rpm. have cleaned ACC and air reg value's

Check wiring to AFM and confirm voltages are correct at ECU and at AFM.

Is the SARD reg set correctly? and what pressure is it ONLY at idle with vac line OFF.

Have you checked for other air leaks that may not be cooler pipe like plenum gasket, inlet manifold gasket, injector o rings etc?

Do a compression test, you need to make sure the engine is good but I doubt there is anything wrong there.

Is the TPS set correctly and have you had someone check the settings in the Remapped ECU?

What were you doing or what happened immediately prior to it happening? and be honest :D

ZILR-34 Experienced

ZILR-34

Posted
  • Author
Posted
Check wiring to AFM and confirm voltages are correct at ECU and at AFM.

Is the SARD reg set correctly? and what pressure is it ONLY at idle with vac line OFF.

Have you checked for other air leaks that may not be cooler pipe like plenum gasket, inlet manifold gasket, injector o rings etc?

Do a compression test, you need to make sure the engine is good but I doubt there is anything wrong there.

Is the TPS set correctly and have you had someone check the settings in the Remapped ECU?

What were you doing or what happened immediately prior to it happening? and be honest :D

for the fuel reg. i was using the standard one untill this problem then i changed over the the sard. on idle its jumping between 20-40psi. without vacume its on 45psi

injetrors are new

ill do a comp test, when i find my tester lol

i was driving like a normal person changing gears b4 3rpm:)

Guilt-Toy Grand Master

Guilt-Toy

Posted
Posted

don't introduce more problems into the system. put the old fuel reg back on untill you fix the problem!

it sounds like a leak in the intake piping to me. id be lookin for a leak. but the first thing to do would be to put the stock reg back on.

The Dan Grand Master

The Dan

Posted
Posted
for the fuel reg. i was using the standard one untill this problem then i changed over the the sard. on idle its jumping between 20-40psi. without vacume its on 45psi

injetrors are new

ill do a comp test, when i find my tester lol

i was driving like a normal person changing gears b4 3rpm:)

Without vac it should be around 35-40. At idle it shouldn't be jumping around unless it's directly related to the engine revs going up and down. How much does it jump around on pressure? and does it move consistently with the revs or does the pressure jump, then the revs go up?

The Dan Grand Master

The Dan

Posted
Posted
don't introduce more problems into the system. put the old fuel reg back on untill you fix the problem!

it sounds like a leak in the intake piping to me. id be lookin for a leak. but the first thing to do would be to put the stock reg back on.

You may be right but I've never seen revs go up to 2k when a pipe comes loose or off. They always go down. This is only what I have seen though, and you may still be correct.

And ditto on the fuel reg. Put the standard one on but get all your pressures checked as well, once it's on.

Guilt-Toy Grand Master

Guilt-Toy

Posted
Posted
You may be right but I've never seen revs go up to 2k when a pipe comes loose or off. They always go down. This is only what I have seen though, and you may still be correct.

And ditto on the fuel reg. Put the standard one on but get all your pressures checked as well, once it's on.

its probly not a 100% leak, might be 50% so when your at 2000rpm in vaccume the computer is probly chucking in 15psi worth of fuel into the cyl because air is leaking and not going into the engine

ZILR-34 Experienced

ZILR-34

Posted
  • Author
Posted
Without vac it should be around 35-40. At idle it shouldn't be jumping around unless it's directly related to the engine revs going up and down. How much does it jump around on pressure? and does it move consistently with the revs or does the pressure jump, then the revs go up?

as soon as i start the cunnt it idles fine and the fuel presure is jumping between 20-40psi. as soon as i give it a rev it goes crazy. idle jumps and its blowning more black smoke. its not just puff puff smoke. it just blows constant black smoke.

as for the piping its all good i have checked and rechecked. but as soon i turn off the car i hear a wissle sound from the turbo side? maybe gasket?

ZILR-34 Experienced

ZILR-34

Posted
  • Author
Posted
check air flow meters, replace them with another set to test if you can or check voltages

if not its a leak. it has to be.

cant be AFM i just put a new one on yesterday.

im thinking its the turbo gasket. i just started the car and when turned off the car i heard a dying wissleing sound from the turbo. but would that stuff up the Air/fuel readings?

The Dan Grand Master

The Dan

Posted
Posted
cant be AFM i just put a new one on yesterday.

im thinking its the turbo gasket. i just started the car and when turned off the car i heard a dying wissleing sound from the turbo. but would that stuff up the Air/fuel readings?

Yeah if you are hearing the compressor sucking in air when it winds down. It could be a small hole in the pipe between the AFM and the turbo. Check the small connections coming off it and the recirc pipe for the BOV there.

blind_elk Grand Master

blind_elk

Posted
Posted
... the fuel presure is jumping between 20-40psi. as soon as i give it a rev it goes crazy. idle jumps ...
Fuel pressure is controlled by the air pressure (vacuum or boost) inside the manifold. if it's jumping all over the place, then you have a problem retaining air pressure inside the manifold.

Have you checked the BOV?

ZILR-34 Experienced

ZILR-34

Posted
  • Author
Posted

found the bloody problem. :P

it was the o2 sensor, cant belive it was that, its only one year old. ;)

after doing all these checks and tests.

order a new one with 4set of sparkies for a dyno tune for next week. ;)

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