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Hi All,

Apoligies if this is not posted in the correct section. Here's the run down on what my car is doing...

About a week ago when I was on my way back from Parramatta, my car started (this is just driving normally, no boosting) started jolting forwards and backwards like I was a learner bunny hopping. I couldnt accelerate through it and when I tried it just got worse, the revs were flucuating and a big black cloud of smoke came out the back of the exhaust, I drove around the corner and the car turned itself off. I managed to pull over, checked under bonnet and nothing seemed out of place, I turned the car off for a little while, it started back up fine. This happened a few times on the trip home... When the car is at idle, the revs fluctuate between 1000rpm-500rmp, then below 500rpm then eventually the car dies and turns off.

This problems happens intermittantly, not 24/7 when I drive. I took it to my mechanic who hooked it up to the comp, determined the problem to be a faulty boost controller which they removed and gave back to me (this is a GFB Boost T). Picked the car up yesterday afternoon... Got no more than 5km down the road and LOW AND BEHOLD same problem, just worse! They seem to think that there is a hissing sound coming from my engine where is may be air leaking from somewhere...

Any thoughts guys, this is frustrating the hell out of me, help would be appreciated.

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It could be numerous things really? if it drives normally then decides to fluctuate and die at idle it could be something to do with your sparkies or dizzy cap? I know i had a similar probably like that before causing a misfire in one of the pistons? soo check that out. It could also be your transmission not engaging and disengaging properly ?? soo you might need to troubleshoot with that a bit as well.

Ummm, R33 Skylines DO NOT use a distributor system, they use an igniter and direct-fire coils.

Here are a few minor things to check:

  • are you sure it's nothing to do with your alarm and/or immobiliser shorting out somewhere or playing up, and therefore cutting off your spark and/or fuel?
  • when the engine is COLD, remove the radiator lid, start the car (if it will start), and see if there are any bubbles appearing in the radiator fluid. This could indicate a blown head gasket...
  • when the engine is OFF, remove your oil filler cap, and see if the oil looks dark and "clean," or if it's a cream-cloured sludge. Do you know if it was blowing a bluish-grey smoke out of the exhaust at all? This is another sign of a blown head gasket, as the oil and water are mixing and creating that sludge.

HOWEVER, considering you saw a big puff of black smoke, I'd say it's either a massive dump of unburnt fuel, or your car is burning oil, which could mean a few things are wrong, including blown piston rings, or maybe even a blown piston...

I'd suggest taking it to a (different) mechanic, and getting them to investigate a bit further. I doubt it has THAT much to do with your boost controller.

When it's not having the issue it doesn't blow any smoke, only when it surges will it blow smoke... I did notice however yesterday on the way home when it started again, I could smell fuel really strong from inside the car... Could it possibly be the fuel pump? They reckon they checked the coils, ignitors everything! Apparently it was hooked up to a computer on the dyno. The car usually runs lean and sometimes has a slight smell of fuel (only very small)

Clean or borrow someone's AFM first and see what happens. Cos I'm certain it's the AFM from these problems you've described.

If not that, look at coilpacks.

hmm a similar thing happened to me today too, my car does idle pretty rough (after cleaning out my AAC valve just yesterday wtf!?), but it doesn't so much bunny hop as it seems to lag, although i can hear the turbo spooling and the boost gauge responding.

:cool: could it possibly be the AFM?

Check for vacuum leaks, the hissing sound could be air escaping/leaking somewhere and can cause the idle hunting your getting. Also can't hurt to clean the AFM whilst your at it.

+1

i had the hissing noises, felt like it was missing and strong smell of fuel, ended up being a vac leak

Thanks for the suggestions guys, I'm still waiting to hear from my mechanic at the moment but I'll certainly let you all know what the go is once I know for everyone's future reference if you hit the same issue. :P I'm hoping it's nothing major...

borrow someones AFM and test it. mate had a problem like this in his 34. he soldered all the joints in the AFM again and it went sweet as. was good when cold but when it warmed up it spat the dummy. but at all diff times. depending on how much of a hard time he gave it. once he did that never had trouble since. best way i think is get it warn and take the plug off the AFM and see what it does. when its dissconnected it should blow black smoke and be runnin rough or stop.

It could be numerous things really? if it drives normally then decides to fluctuate and die at idle it could be something to do with your sparkies or dizzy cap? I know i had a similar probably like that before causing a misfire in one of the pistons? soo check that out. It could also be your transmission not engaging and disengaging properly ?? soo you might need to troubleshoot with that a bit as well.

Did your mummy tell you that you could use her computer?

air flow meter . end of storey . does it sound like a rotary with a lumpy idle when you try drive it and it bunny hops?

Dont be so sure, i have the same problem but it is happening all the time, no vac or boost leeks and i have changed the afm but nothing has fixed it so far.

Hi all,

Got that phone call from the mechanic yesterday I was waiting on. Results are that it was a combination of 3 things...

1. Cracked faulty boost controller (it's a GFB boost t)

2. AFM (yes you were all right thanks guys)

3. BOV, something had actually gotten inside mine and was clogging it

I'm having a top of the line Gizzmo in car boost controller installed, it has 6 phases and a 15second extra boost interval.

So I'm picking it up this afternoon, I'm really hoping that this is all fixed. Thanks for all your input, appreciated. :yes::D

i had the a similar problem the car just shat it self after i did some work to it and i went throw and checked every thing i had know idea what was wrong. my dad had a look and a plug wasn't pushed in properly and u know what it was the AFM it wasn't plugged in properly.

it is always the one thing that u forget to check lol

like my uncle he has a old monaro with every thing done to it mid 2 low 10sec car and one day it just shat it self and died and he didn't know why. he thinks that it was the alarm that he just fitted so he takes it to the mechanic the guy reaches under the car and knocks on the gas tank it was bone dry. omg lol lol lol i was like.

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