Fuel Cut Never Ends!

Mo95Talon · 04-13-2008, 02:10 PM

I have checked for leaks over and over and over. I fixed all of them. I am running a T25 at 12psi (stock), FMIC short route piping, Greddy Type RS BOV recirculated, Apexi 3inch downpipe, 2.5 inch apexi cat back. What am I doing wrong? Can anyone help me?

JayRolla · 04-13-2008, 02:15 PM

So what boost level you doing your tests too and also how long does it hold that boost, how fast does it drop off when testing???

Mo95Talon · 04-13-2008, 02:43 PM

I test at 13psi. It drops 1psi every 5 seconds.

JayRolla · 04-13-2008, 02:48 PM

Not bad, I would leak test up to 20psi at least, you may not be putting enough pressure in the system to find the real leak. It has to be a leak unless the maf is bad but that would usually through a CEL. Do you have a boost gauge?

Mo95Talon · 04-13-2008, 02:55 PM

Yes I do have a boost gauge. Do you think maybe I am quite possibly out running the injectors? I can't imagine running 450's out at 12psi on a T25... I guess I will test at 20psi. I don't have a cat and it is throwing a CEL because of it. But I didn't think that made a difference.

JayRolla · 04-13-2008, 03:16 PM

No your injectors should be fine. Even if you run out of injector it wont cause fuel cut. Only over running the maf from too much boost, like what a boost leak would cause.

Mo95Talon · 04-13-2008, 03:25 PM

Went and tested at 20 psi. same results. I had numerous leaks when I started about a month ago. 3 on Greddy BOV. One on the intake pipe (stock with hole in side fixed it). Any other suggestions? Or am I

!

Mr Peepers · 04-13-2008, 03:35 PM

Are you sure it's fuel cut? It wouldn't hurt to check your plugs/wires and make sure they are gapped to .028". You should be running NGK BRP6ES's for that boost level.

Also, what is you boost gauge reading at idle? If there is a leak in the line it will be off during boost/vacuum. I'm not even sure if a t25 can flow enough to cause fuel cut anyway though without it being from boost leaks.

spectr019 · 04-13-2008, 03:57 PM

I had that problem awhile ago...it didn't really feel like fuel cut, I've personally never had it, but I've read that you will most likely look behind you if you get fuel cut to see if something (your engine) fell off!! But no, I would check the wires if you are still running stock wires. It really depends on how hard you are pushing the car...My stock wires died at only 36,000 on the car!! But yes, you'll get kind of a dying feeling if even one wire is just bad. I ran 18psi on the T25 when I had that in and no, no fuel problems. Chances are your fuel isn't the problem. Good luck!!

Ben

JayRolla · 04-13-2008, 04:06 PM

Fuel cut completely cuts the engine off, its like hitting a brick wall. Is that what your car is doing?

Mo95Talon · 04-13-2008, 05:24 PM

I am almost positive it is fuel cut...It only happens in the upper rpms at WOT and BAM! Yes feels like a brick wall. Boost gauges read 20 vacuum at idle. Plugs gapped correctly (NGK BRP6ES) and new plug wires.

JayRolla · 04-13-2008, 05:27 PM

Hmmm, very confused what else would be the issue. I guess you could always through in a maf-t,

.

Mo95Talon · 04-13-2008, 05:56 PM

Actually I want to... but I was always told I need to solve the fuel cut problem before I do that. Is that true?

JayRolla · 04-13-2008, 06:08 PM

It could fix the issue or not, It will be a bandaid fix if you did it. I really think you loosing boost somewhere. Its the only logical explanation.

Mo95Talon · 04-13-2008, 06:17 PM

Well crapo! I appreciate all the help. I will do some more boost leak tests. Where should I check for leaks other than the couplings, bov, intercooler, and throttle body?

JayRolla · 04-13-2008, 06:22 PM

Injector seals!!, when they get old they will leak. If they are original then they most likely are leaking.

Mo95Talon · 04-13-2008, 06:41 PM

How hard are those to change? I have never done them.

JayRolla · 04-13-2008, 07:55 PM

Not hard at all, just have to remove the fuel rail.

spyderturbo007 · 04-14-2008, 08:40 AM

This should help.

Mo95Talon · 04-14-2008, 05:05 PM

Thank you guys. I know that when I come here for help and info you guys always have answers. Thanks again.

welfle18 · 04-14-2008, 05:57 PM

You could also do the fuel pump rewire. This would also help to eliminate fuel cut and help you to find whether it is fuel cut or not. If it doesn't solve the problem then you know its something else. Just a suggestion. But I ran my t25 and stock injectors at 15 psi and never once hit fuel cut.

Mr Peepers · 04-14-2008, 07:55 PM

Quote:

Originally Posted by welfle18

You could also do the fuel pump rewire. This would also help to eliminate fuel cut and help you to find whether it is fuel cut or not. If it doesn't solve the problem then you know its something else. Just a suggestion. But I ran my t25 and stock injectors at 15 psi and never once hit fuel cut.

Fuel cut is caused by your ECU seeing x airflow, not overrunning your fuel system.