Car Almost Stalls After Revving - Help?

[gzrecoil]

Hey guys. Sorry I've never posted, been a member for a while now but haven't been too active.

Hope you can welcome me to the communityl I left a post in the newbies section of wasteland.

I have a R32 Skyline GTR that is having problems(lots of problems )

When I rev my engine above 4-5K, and let it drop, it almost stalls. It goes down as low as 500RPM and you can barely hear the engine for a moment and then it starts back up.

Any idea?

I have recently replaced all spark plugs to PRF6A-11 with .8mm gap, also replaced two coil packs that appeared bad, and I also addition taped my current coils with electrical tape although there were no cracks, and replaced the fuel filter.

I also have a hesitation and complete loss of power around 5K that I was hoping the above could fix, but I can't get it out on the road to test it for a couple weeks.

In regards to the almost stalling problem I have found these could be the problems:

Coil packs(Need to test), wires to coil packs

Vacuum leak

Over-Rev (Bent valves)

Bad injectors

Fuel pump

Head gasket

Throttle body

IAC valve?

I do see a little oil where my spark plugs sit if that matters at all

Can you list thess in order of most likely, and if you have any to add?

In regards to the hesitation problem:

Mostly the same things as listed above except crank angle sensor or o2 sensors could need replacing.

The car runs extremely rich. The mods currently done are a Greddy VTA BOV, N1 turbos @ 1bar, larger intercooler, oil cooler, 300lph fuel pump, apexi filters, trust dump, 3" apexi exhaust, straight pipe, that's about it.

It seems to have problems with low fuel when going up hills, and I can't seem to empty 3/4 of the tank but I could be hallucinating and my gas gauge is broken.

I cleaned the MAF's already so I don't think it's them.

Any help is greatly appreciated. It's summer time and my baby just keeps sitting in the driveway, I'm starting to get really sad

Edited June 1, 2011 by gzrecoil

[gzrecoil]

I should also note that one of the spark plugs that I put in is very charred.

Although it was at 1.1mm gap, now .8mm, the car was never driven since they have been put in, only idled about 4-5 times to warm it up.

See attached picture below. Charred is on right, all the rest look like the one on the left. I wish I knew which cylinder this came out of. I at least know I put it back in cylinder 1.

Edited June 1, 2011 by gzrecoil

[T.D]

Hey mate, the stalling issue sounds like one of two things so far:

- Vacuum leak (check all your hoses and piping)

- BOV (I presume it's a vent-to-atmosphere one?)

If you don't have an aftermarket ECU (be it a full standalone like Power FC or a piggyback or a re-mapped stocked ECU) then I'm fairly certain that it would eliminate your running rich problem, hesitation problem, as well as your stalling issue (provided it's not a vacuum leak and is BOV related).

As for oil on the plug, that doesn't sound very good but have you got a compression test done?

[gzrecoil]

Yes I do have a VTA BOV, a greddy one. I don't know anything about how it's hooked up.

I will have to figure out all the vacuum hose locations and trace them I guess, not looking forward to that.

I just bought a compression tester so hopefully I can test tomorrow. Just need to locate where the CAS is to remove it for the compression test, I'm a noob lol.

[T.D]

Ahhh I see. More than likely it's your BOV that's causing the stalling issue. If you have the stock one, chuck it back on and check if your car is still playing up but I'm almost certain it's the BOV playing games lol

As for the CAS, it's the round metal thing poking out of the cam gear cover

[gzrecoil]

Thanks. I did a quick google search for CAS last night and realized that.

After reading a lot about VTA BOV's I agree this very much could be causing the problem since I'm still running MAF's.

I wish I had enough money to take the jump to a Power FC D-Jetro w/ MAP sensors but I think I'll take the cheap route and try to find some stock recric BOV's.

Will post up my findings when I can find some to use.

[T.D]

You don't neccaserily have to go MAP sensors to run a vent-to-atmosphere BOV. Even just a piggyback can be enough to get around the stalling issue as the tuner can subtract fuel to avoid it from stalling

But yeah, cheapest option is stock BOV. Otherwise, almost any kind of piggyback ECU will do the trick I had the same problem a little while ago too but I chucked in a Greddy E-Manage (which I'Il be selling in the near future *wink wink nudge nudge* haha) and got it tuned and it's all happy now

[gzrecoil]

We'll see... I would love to have something but haven't had the money.

Curious, I'm being told if I have the right size flange I can make the greddy bov recirc? If that's the case I wonder if I should try to acquire stock piping or make some myself and buy a flange somewhere.

So confused... Picture of my BOV attached.

Edited June 3, 2011 by gzrecoil

[Johnny]

Im very sure its the bov. My old s15 would stall or drop idle after acceleration then coming to a complete stop; my fix was to put it into neutral and give a quick rev when slowing to a stop.

Id definitely pop on a stock one and if thats the fix then pick up a stock gtr bov to put on

[gzrecoil]

I found this recirc adaptor I just don't know what kind of piping to buy or where to hook it up.

http://www.frsport.c...product_id=1309

Edited June 3, 2011 by gzrecoil

[gzrecoil]

If I were to buy the attachment above to recirc the Greddy Type RS where do I run the piping to?

I don't have the stock recirc piping or anything so I assume I will have to fab it.

Would really appreciate your guys help, I really could use this car on the road for the summer

-Recoil

[gzrecoil]

Ok, so i see it goes in after the MAF, I'll have to look tonight to find out where I can run a tube. I haven't noticed any open plugged holes before.

My BOV is on the left side of the motor by the battery, and intake is on the right.

I would have to run a tube across or under my motor, or relocate my BOV (No clue how to re-locate)

Should I buy an SAFC or an idle stabilizer or should I just go re-circ?

I could care less about the noise, reliability and cheapness of fixing the issue are the most important things here.

Edited June 3, 2011 by gzrecoil