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

[boostedtsi0069]

i really dont know how much psi im pretty sure its set at stock. I have a 16g i dont think it will make it go up, and yea stock injectors and fuel pump.

[92dsmtalon]

Ok, well, on the 16g with having stock fuel system, it probably is fuel cut. Also, Im guessing you dont have a boost gauge, you need to get one of those. Also, upgrade your fuel system, because the 16g deffinatly isnt stock boost.

[spyderturbo007]

Fuel cut has nothing to do with fuel delivery so you can replace your injectors and fuel pump all day long and it won't do a thing. Fuel cut is caused by hitting a preprogrammed airflow value hardcoded into the ECU's programming.

If you are running stock boost on the 16g, sounds like you have a boost leak somewhere.

[laserspeeddemon]

Originally Posted by spyderturbo007

Fuel cut has nothing to do with fuel delivery so you can replace your injectors and fuel pump all day long and it won't do a thing. Fuelcut is caused by hitting a preprogrammed airflow value hardcoded into the ECU's programming.

If you are running stock boost on the 16g, sounds like you have a boost leak somewhere.

We have a winner. Boost leak test time.

[spyderturbo007]

Originally Posted by laserspeeddemon

We have a winner. Boost leak test time.

Nice, what do I win Sean???

[JohnnyT]

I would look into the world of EPROM editing, you can get rid of fuel cut through that and tune your car at the same time. I would recommend having hardware that can support what you tell the car to do though, or else KABOOM! Ds-Map is not new but kinda a big deal, look into ithttp://www.ds-map.net/ also tuning is not easy and there are lots of options.

[boostedtsi0069]

Ima do a boost leak test and c what comes up thanks guys ill keep it posted. Also can it be the tps sensor?

[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

[oldman]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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?