engine dies with maf

[usafboyer041288]

I have a 93 240sx with a s13 blacktop. i try to start it and it will start up but it revs up twice then dies. it has a z32 maf, bc 264 cams, bc retainers and springs, 750cc injectors and a r.s. enthalapy tuned ecu. if i unplug the maf it will start and idle but wont rev past 2500-3000 which is expected. but once its plugged in it falls flat on its face. im stumped.

[NJs13_1993]

If you cancel out the maf and it idles, I would try swapping the maf with another. Maybe one that you know works

[usafboyer041288]

I have two and they both do it. One came off of my buddies running 300zx so I know it's good


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[S-Nation S13]

MAF wiring could be the problem. recheck the wiring make sure nothing got messed up, never know.

[Driftwire]

you have to have 2 seperate grounds. One of the grounds should be on the harness and the other should be engine ground. Or else youll get issues like this. Double check the wiring for sure and start there. Also one of the pins on the harness plug could be loose. I also had an issue like that would cause it to think my maf was unplugged

[usafboyer041288]

Hmm I'll have to check that. The harness is from wiring specialties. It seems to be sitting flush on there. I have a wire for the harness and a wire to the chassis.


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[economix]

I'm interested to see how this pans out for you since I have a VERY similar issue with much of the same parts you have...cams, enthapy tune, Wiring Spec harness, fuel injectors, etc....

[usafboyer041288]

@economix is yours stalling out to


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[economix]

Not as immediately as it seems you are. Mine runs for a shade, terribly though, and after checking all the electrical it seems like it's just fine. I actually have to unplug my fuel pump fuse to fire it up then plug it back in quickly to get it to stay on. Taking the MAF off or putting it on, makes zero difference. So maybe my MAF, but the fuel fuse is throwing me a wrench. I wanted to see how yours panned out first tho before plaguing you with my slightly different but seemingly alike issue.

[usafboyer041288]

My buddy had an issue with his pump it wasn't getting enough voltage or something so he made a relay for the pump. His battery is relocated to the back so the only wire he used from the harness is the signal wire so it knows when to turn on and turn off other then that it's self sufficient.


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[htc.zenit]

Are your running Stock Turbo and intake piping?

[usafboyer041288]

Stock turbo but not a stock Intake. The car came with a Godspeed knock off version of the greddy. It's also got a fmic. It has a hks actuator on it as well


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[htc.zenit]

Reason I'm asking is simple. If the MAF sits to close to the turbo, there might be turbulences causing the MAF to misread the air => problems.

I had this issue when I went Top Mount and didn't have enough bends before the turbo inlet.

But as long as you have the original "styling" of the intake piping this should not be the cause of your problems...

[LoSt180]

Originally Posted by htc.zenit

Are your running Stock Turbo and intake piping?

I think he's asking about the intake between MAF and turbo, not the intake manifold here. Along these notes, do you have an air filter on the Z32 MAF? Years ago I tried running without an air filter, and the car would barely stay running, too much turbulence at the inlet of the MAF.

Has the car ever ran with this setup? If not, there might be an issue with the tune.

[usafboyer041288]

It's the stock rubber hose between maf and turbo Inlet. And yes I have a filter on the end. This tuned ecu I have not ran on it yet so maybe the tune is messed up


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[Bleakley]

The thing about mail order tunes from enthalpy and jwt is you know FOR SURE they are going to work out of the box (with a few exceptions)
Focusing on enthalpy.. Enthalpy has tuned over a THOUSAND SR's. The tunes have been ironed out long before your sr. A mail order tune assumes all the sensors and other parameters of the engine are on point.
If you slap an enthalpy or jwt ecu on your car and it's not running right, 99.9% it's your fucking car man. Do not blame the tune.

How long was it from the time you received the ECU to the time you started the car up with the ECU? A flashed ECU can only sit for a couple months off the car or something and then it goes to shit. I was crawling through some threads and saw this pop up (twice I think). Pretty sure enthalpy even confirmed this when someone e-mailed/called.

Speaking of which, Enthalpy backs his products 3000%, if you're having an issue, he will help you sort it out. Being that he's probably seen and heard it all by now, it would definitely be worth the call.

I feel it's definitely something to do with the MAF if you can unplug it and it has a decent idle and rev pattern. Whether it be wiring, the unit itself, or what have you.
Is it an actual N62 MAF?? And we're 100% sure enthalpy knew to drop the z32 maf into the tune? (via invoice, etc.) Being that this is an S13 blacktop, what ecu code/number are you using? And what O2 sensor are you using? Skinny, fat?
For sure, no guesses...

[usafboyer041288]

Hmm didn't think of that it sat maybe 2 months maybe. And yes it's a true n62 maf. I have a e5 ecu and A fat o2 sensor


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[Mitsubayati]

MAF wiring or bad vacuum leak somewhere. Make sure the wires are where they are supposed to be.

[Kingtal0n]

boost leak