RB25 died abruptly, now won't start

[chixwithtrix]

At a drift event today testing out the new 3076 externally gated turbo and associated different setup parts with that on my track car. Boosted to 1 bar (boost controller was not working earlier in day and it boosted to a bit over 2 bar so we removed the controller and ran the 1 bar spring). Later we had a problem I cannot fully pinpoint

SetupRB25detGT 3076Apexi PFCTial 38mm wg, 1 bar springstock manifold modified for wg flangeZ32 MAFNismo FPRGreddy intake mani

Beginning of the day idle was very rough and surged (like the PFC was trying to learn it, but stayed like that to rest of the time). Before this turbo swap the idle was smooth, no surge and no burbles. Would smooth out in high RPMs. One run went through 1st, 2nd, 3rd, bam, car shuts off still going in a straight line before the 1st initiation point. Shut off, no warning, no nothing, but all electronics (gauges, etc) were still on.

Rolled back to pits, tried to start but all it would do is fire over and quickly die (start, vroom, die, try again, start, vroom, die, etc). Checked fuel and it was getting it, it got spark because it was firing over and then dieing. Had one of the tech guys out there check over the car and the PFC said the MAF signal was not reading...? Tried checking the ground and put a multimeter on the maf sensor plug signal wire and the pinout at the ECU and it completed a circuit. Only thing left is to check if the MAF is bad?

Any other things that would cause it to do this other than the MAF? Would dieing abruptly be caused by a bad MAF? Unplugged the MAF and tried to start and it still did the same thing. The tune was not changed from the previous turbo setup and I'm pretty sure if it needs a tune as well.

Its a lot, but I've put so much damn work and money into this car and need some input because I'm stuck.
Modified by chixwithtrix at 8:03 PM 6/14/2009

[mattblancarte]

I'm pretty sure if it needs a tune as well.

You could try cleaning the MAF. Any leaks, smoke, etc.?

[mattblancarte]

I'm pretty sure if it needs a tune as well.

You could try cleaning the MAF. Any leaks, smoke, etc.?

[nismo8117]

yea its like when you unplug the maf and try to run the car without it and give it some gas...it will just die...check you maf out clean as matt said or try and use another if you have one laying around

[chixwithtrix]

No leaks, no smoke, plugs are mousy brown.

If the MAF is dead like the PFC is telling us the signal is non existent, spraying or cleaning it probably won't help, but we'll try that out. I'm still out of town here the event was so trying things out will have to wait.

It does sound like the MAF is the culprit, but I want to keep my options open to possible other problems so I don't go barking down the wrong tree. Heck, there can be multiple problems with my luck. This car has never run for a full event, its frustrating.

I'll see if I can borrow someone's z32 MAF, but not a lot of people just have those lying around where I am. After having to spend a couple grand to get the new turbo in I still need a $600+ tune and $100+ MAF. Running me Broke.

Thanks for the input, if anyone has info or ideas post it up!

[krayton]

do u have a oil pressure gauge? check your oil for shavings

[chixwithtrix]

yeah I have an aftermarket oil pressure gauge and the oil pressure was fine. If it was a loss of oil pressure problem I doubt it would have these symptoms. Wouldn't it have coughed or sputtered or given some kind of warning first? The abrupt shutoff just seemed more electrical in nature and the fact that it turns over easily is a plus.

[240z4u]

The maf is a likely culprit. Have you made sure you have power and ground at the correct pins?

Evan

[USMCgetsome]

i agree with the above post.

[chixwithtrix]

The maf is a likely culprit. Have you made sure you have power and ground at the correct pins?

Evan

Yes, as I said in the first post we checked ground and put a multimeter on the signal wire from the MAF to the actual pinout in the ECU and it was fine

Might have found a cheap N62, once I get that lets hope thats the only problem. Then off for a tune

[gawdzilla]

probably maf. since you have the pfc, go to etc. -> sensor/sw check and look at the AFM voltage. it should read something when the ign is on. then blow into it and see if the voltage goes up. if it doesn't, or if the afm voltage is highlighted in black, something is wrong with the maf or your wiring.

[chixwithtrix]

Borrowed a MAF, put it in and it worked.

So it was a MAF problem, at least thats a pretty simple fix. Thanks for all the help!

[silviasgp06]

Hey glad you fixed it!, off topic but glad to see you on the RB section. I dont know if you remember me or not but im the guy who did the quick fix on your electric fans with safety wire at mineral wells last season.

[l0nestar]

Glad you got it fixed. Thought it was MAF / AFM from initial post.

[chixwithtrix]

Hey glad you fixed it!, off topic but glad to see you on the RB section. I dont know if you remember me or not but im the guy who did the quick fix on your electric fans with safety wire at mineral wells last season.

haha, yeah I definitely remember that. That was its first event. Fortunately that has changed since then lol

[240z4u]

Its nice to hear a success story from time to time.

Evan