SERIOUS PROBLEM with my GTR!! HELP ANYONE!

[rockcrete]

It's definitely an air leak then, with the mafs unplugged, it makes the air leak irrelevant as it runs off the tps and a chart. Get back to looking at all your connections, your best bet is to pressure test your system.

[shaz10]

this saturday, the bumper comes off, going to check the intercooler and all connections for leaks. Not 100% sure how to pressure check the system but it should be in the manual right? Although i haven't solved the problem yet, i do appreciate all the help you guys are providing.

[atmguy]

I would try to block of the piping at the plenum. Then figure out a way to push about 15psi or so through there from where the rubber elbow off the turbo collectors begin... I'm not sure, just an idea.. I have never pressure tested before...

Maybe a plumbing store would have some pipe plugs that would fit in there. Then you could drill and install a brass nipple on one of the pipe plugs so that you could connect it to an air tank and slowly rais the pressure....

[shaz10]

good idea i'll look into that.

also what i was thinking, the car is running VERY rich, would it be advisable to reset my ecu and put it back into learn mode? I want to try all options that are the least invasive and most inexpensive that are possible. Suggestions?

[rockcrete]

I clamped two rubber balls in my ducting in place of the mafs (to seal it) and the disconnected the hose from the rocker cover that goes into the intake piping and put my air gun nozzle in there to pressurise it. The amount of pressure isn't too important, you'll see the ducting bulge as it comes under pressure. Use some vice grips to crimp the hose to hold the pressure once you have some in there. I'm betting you have a pretty big leak though, so you'll just hear it rushing out somewhere.

[shaz10]

rockcrete, very good idea, i will do that.

also what do you think about resetting the ecu?

[rockcrete]

Don't worry about the ecu for now, it's obviously not the problem.

[atmguy]

Like rockcrete said the ECU is unlikely to be the cause here, but, if you find a leak, I would still reset it, for fun if nothing else! :P

[atmguy]

Soooo.. What's the status?

[shaz10]

Update:

Ok guys so here's the status update. So i don't think its the MAF's anymore. I had a friend bring his GTR over (its running perfectly) and i installed his MAF's and reset my ECU, still stuttering. Although my car will run now but not very well. It still wants to stall and is still having issues when idling, keeps bouncing from 500 at the low end to 1100 at the high end. The sound has also changed and it sounds like its struggling to stay alive. There still is quite a bit of carbon flying out of the tail of the car, enough to stain the wall and when i put my hand infront of the exhaust i have black jelly carbon particles on it. And when i put my rebuilt MAF's on it it will still run just not clean so i have ruled that out as a problem. What else could it be? I feel like the timing may be off or the car may be misfiring. I think im going to have to tow it to a mechanic to have it looked over at this point. Before i do i was thinking to try taking off the bumper to check the intercooler piping for leaks.

Could it be my Coils or plugs?

I also confirmed that i have blueish/black smoke coming out of the tail, its running so rich its terrible. I need to fix this ASAP, i was going to go up to wasaga beach on May Long for a meet, doesn't look like i can make it anymore

[sushtsi]

Not sure if i asked this before or not, but on your boost gauge what vacuum reading are you getting when the car is running?

[shaz10]

there is no positive boost, its hovering at like .3 Bar, when i step on it it moves up to 0, but wont go into the positives and the blow off's aren't making noise anymore. It feels like i have a vacuum leak somewhere or something along that line.

I know that BOV's can sometimes cause problems, now i have HKS SSQV's, could something be wrong there?

All i know is the car is getting too much fuel and not enough air, otherwise im lost. I dont want to go and spend $$$$$ with a mechanic trying to figure this out if its something simple. If you guys think this is a complex problem i'll have it towed to my mechanic and take it from there. If i can save on labour by doing it myself then i will.

[sushtsi]

there is no positive boost, its hovering at like .3 Bar, when i step on it it moves up to 0, but wont go into the positives and the blow off's aren't making noise anymore. It feels like i have a vacuum leak somewhere or something along that line.

I know that BOV's can sometimes cause problems, now i have HKS SSQV's, could something be wrong there?

All i know is the car is getting too much fuel and not enough air, otherwise im lost. I dont want to go and spend $$$$$ with a mechanic trying to figure this out if its something simple. If you guys think this is a complex problem i'll have it towed to my mechanic and take it from there. If i can save on labour by doing it myself then i will.

So you are getting .3bar of vacuum? Thats only like 4.35psi, definetely sounds like a leak to me. Did you triple check all ic hoses/connectors in the engine bay?

[Stinky_1]

Shaz,

If you were a doctor and somebody came in to see you and said "my back hurts". WOuld you look at their hands and say "no, I think your fine"?

You have been told many times that its a leak in your intake system somewhere, but instead of pulling the bumper off and checking everything you seem to be looking at everything else. I said on the phone I didnt think it was Maf's, many people on here have said the same thing. It is great news that you were able to test the good ones from that other guys car.

So now, all you really should be doing is getting that bumper off. Its not difficult. Just need a f,at screwdriver to pop the pins out on the top, and a philips screwdriver to get at all your bolts. There are 2 under your side marker lights so you need to pull those off as well. Otherwise its very easy and takes maybe 15 minutes.

Once you get it all off I would actually PULL the couplers off that you can and clean them up in some soapy water. They will be filthy inside and out anyway and it will help to see if there are cracks in them.

ALso take a good look at your clamps, if any look stripped then its time to replace them.

This deff sounds like an air escaping problem.

Just to help you understand whats going on Ill explain it a bit.

As the air rushes over your mafs it tells the ecu how much is coming in. The ecu then "assumes" that all that air passing the mafs is making it in to the engine. It then puts the amount of gas that it needs to mix with that air for the car to run.

Now, if you have a hole or leak somewhere all the air it had go past the maf would NOT make it in to the engine. It still adds all the fuel it would normally need for all the air, but since its only getting half the air it makes it run really rich!

You need to find where you are losing that air and plug the hole. You will then instantly get your car running good again.

ALso, you should note that the circumstance your explained for when it happen do NOT lead me to beleive its anything to do with the mafs. I have never seen BOTH of them suddenly fail one day. Its usually a long slow process. But blowing a connector or hose clamp is for sure something that would happen all of a sudden, and the car would run like garbage until it was fixed.

Take our advise, spend 3 hours and get that bumper off and find that leak!:hit_head:

[shaz10]

Stinky,

Wicked explanation, and yes i will be taking the bumper off. This weekend i will give an update! Thanks for all the help provided, you guys have been really good about this. I will inform after i check it out.

Cheers,