The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support STM Tuned
Please Support ExtremePSI

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

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Slanted J

Supporting VIP
131
3
Feb 19, 2002
Janesville, Wisconsin
All fuel cut threads are combined here.

I've tried doing a search but to no avail.

I was just wondering what Fuel Cut is. I've heard it tossed around alot, but do not actually know the details behind it. And, naturally, I can gather that its when the fuel is cut off, but when and why.


Thanx,
Jon
 
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.
 
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.
 
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.
 
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.
 
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
 
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?
 
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.
 
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".:thumb:
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.
 
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.
 
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.
 
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.
 
Holy 75page fuel cut / boost leak / grammer thread OMG

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 :dsm:
 
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?
 
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

:thumb:
 
I am having a problem that might be fuel cut, but i never get the chance to build boost. Just done balance shaft removal. Refurbished stock motor, all new gaskets inside and out,hoses, plugs,wires.....1st test drive today. If i gradually hit the pedal more and more it eventually bucks hard at aprox. 2500 rpm. If i hit the pedal aprox. 10% and hold it there, it does not. If i floor it , it eventually works its way threw it and goes. Everything is stock, injectors,turbo,fuel pump. No emissions................I am NEVER under ANY boost when this happens..... Checked t.p.s. also
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top