Fuel Cut: What is it? How do I fix it? [merged] - Page 79

teenvette77 · 10-17-2007, 04:44 PM

Srry to jack your thread, but i am having this same problem and have checked everything, replaced the ignition system, fuel delivery........yada yada yada. Laserspeeddemon mentioned that fuel cut is an airflow amount. I was wondering if a piggyback could have made the ecu hit this point? thanks

oldman · 10-17-2007, 04:52 PM

Quote:

Originally Posted by teenvette77

Srry to jack your thread, but i am having this same problem and have checked everything, replaced the ignition system, fuel delivery........yada yada yada. Laserspeeddemon mentioned that fuel cut is an airflow amount. I was wondering if a piggyback could have made the ecu hit this point? thanks

The answer to fuel cut is almost always "boost leak test", did you miss that part?

matthewdesigns · 10-17-2007, 05:19 PM

Yes, a piggyback can help create fuel cut if it's adjusted into the positive, and you are close to fuel cut already. It fools the ECU into thinking there's more air flowing if it's positive.

teenvette77 · 10-18-2007, 03:08 PM

Thanks matt, i was messing with it recently and probably tuned it wrong.

Oldman, i dont have a boost leak thats why i asked. But thanks for the "help".

oldman · 10-18-2007, 03:18 PM

Quote:

Originally Posted by teenvette77

Thanks matt, i was messing with it recently and probably tuned it wrong.

Oldman, i dont have a boost leak thats why i asked. But thanks for the "help".

If your piggyback is on the positive side to facilitate fuel cut, something is already wrong as the stock fuel map is at about 9.5:1 under WOT so your piggyback shouldn't be on the positive side regardless which injectors you have, unless of course the only modification is the MAF which will off set hitting early fuel cut anyway.

teenvette77 · 10-18-2007, 03:24 PM

Thanks oldman, ill do another boost test. This thing is realy getting to me. It seems to lessen and almost dissapear with a full tank and fuel treatment but ill take any advice now. Thanks again

Talesin · 10-18-2007, 03:32 PM

JohnnyT, eliminating fuel cut is no way to compensate for a boost leak. It's a half-ass fix that WILL destroy your engine given time.

dsm908 · 10-18-2007, 03:52 PM

i had the same problem and just as posted BOOST LEAK..... also what type of gas are you filling up with ? , please not regular....

oldman · 10-18-2007, 03:53 PM

Quote:

Originally Posted by dsm908

i had the same problem and just as posted BOOST LEAK..... cross your T's and dot your i's

Or capitalize your i's and dot the end of your sentences.

.......seriously.

teenvette77 · 10-19-2007, 05:01 AM

no not regular, im not that much of an idiot. 93 octane and im only runing 15psi max. Im sure its a boost leak that developed recently. I poped the hood yesterday to adjust my idle screw and i think i could hear air coming from somewhere. Nothing i remember hearing before.

Talesin · 10-19-2007, 08:27 AM

So build an IC leak tester (vfaq.com has a how-to) and do a proper boost leak test.
90% of people whose cars unexplainedly 'feel slow' or hit fuel cut without running a whole lot of extra boost with no compensation have a boost leak or two somewhere. I'd recommend checking monthly, as they can and do develop under normal daily driving situations, without anyone wrenching on anything under the hood.

DSM90AWD · 10-19-2007, 09:01 AM

Holy 75page fuel cut / boost leak / grammer thread

For those that have joined recently, be sure not to confuse "fuel cut" with engine misfires or knock-induced timing retard. Fuel cut feels the same as if you hit the Rev Limiter wheras the others feel more like rough acceleration and/or the car is being held back.

In any case, you should leak test anytime you re/re any piece of the intake tract post turbo. Also be aware of loose connections pre-tubo that would introduce unmetered air to the system

Rob88 · 11-09-2007, 09:15 PM

ok so i am hitting fuel cut i know that my logger shows the injectors going to 120 or so % and shutting off also i see my maf signal goes to 1602hz or something around there...basically maxes out. I have a gm maf and maft im running 12PSI now only because thats max i can get without fuelcut. i run a 11.2 afr. i have checked for boost leaks found one on the throttle shaft seal. fixed it and made alittle better i guess. pressure test again and found that my MBC has a hole in it that is suposed to prevent waste gate lock up. but under pressure it leaks could this be what is causing my fuel cut? should i get a different MBC?

killab443 · 11-10-2007, 01:00 AM

thats a bleeder on your mbc. take the mbc off and do a pressure test with the hoses blocked off

forcefed86 · 09-15-2009, 07:15 PM

Ways to get around fuel cut on a non-socked ECM 93 eagle talon tsi.

On my old car I used a adjustable pot. inline with the altitude sensor in the maf.

I've since purchased another 1g 93 talon. And I'd like to do the same with it but I can't seem to find the write up on it. I'm already running a 255 walbro. Still using stock injectors. Of course I'd be monitoring the AF with a wb02 and then using meth injection for additional enrichment. Still on stock injectors and big 16g evo III turbo.

My deal is I don't really need the larger injectors since I'm using pure meth injecton as my enrichment. But I'd like to max out the usable power of the big 16G. I get fuel cut now at 19-20psi with the lower MAF screen removed. I hear the 16g is good for 24ish lbs?

thanks