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

[Slanted J]

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

 

[awd93talon]

My car is doing the same think at 4K, but i took some gas away with the afc at that rpm and that stoped it

 

[mattsdsm]

so does anyone have any solutions or ideas of what it could be am I running to high of boost or to small injectors I dont know but my AF gauge almost goes off the chart towords lean every time it happens. But is there any one else this is happening to I really need to fix this because races are coming I need it to run right.

 

[blackgst256]

OK I have a few questions. This is what i have so far- fmic, intake, 3' downpipe back exhaust, 255 pump, evo 3 16g, mbc, plugs and wires, hks ssqv, boost guage and oil pressure guage. I have that all installed right now and i have 550 injectors in my garage which i will be putting in soon. Now i know im goin to get a super afc 2, fpr, electronic boost controller, cams and gears within the next few months but my question is if i put the 550's in without the afc or fpr will it run alright or will it be going crazy? right now i have it at 18 pounds and last night when i was on it in 2nd and 3rd hit it what i think was fuel cut a few times. Now i know that turbo and the injectors dont mix so i was wondering if that was why it was cutting out like how it was or could there be something else. and in put on this would be helpful. Thanks

 

[GSTdude06]

you need a fpr with the 255 fuel pump or youll run rich cause the stock one cant keep up with it.

 

[robs90tsi]

Ummm ya, your running a 16G at 18psi on stock injectors??????????? What the are you thinking? You are rediculously maxing your injectors, turn your boost down to like 16 max before you break something. Also, you should get a logger, its really important to know whats going on inside your engine before you start tuning, a logger will also show you your injector duty cycle, and I can guarintee that you are way more than maxing your stock injectors.

 

[EclipseTrbo420A]

Just turn it down to 16 PSI untill you get the 550's in and the afc in AND a logger of some sort.

then you will be entirely safe.

 

[zippyshoe]

Also, make sure that you set up your afc BEFORE you try installing the 550 injectors. Your ECU has no way of knowing that you are no longer using the stock injectors and will not be able to supply the proper amount of fuel. Also, as stated previously, install an afpr as soon as possible if you wish to continue using a 255 fuel pump.

 

[blackgst256]

yeah i figured that it was to much for the injectors but will i be able to put the 550's in for the time being without either an afc or the fpr?

 

[blackgst256]

they guy who had the car before me said when he had the 550's in the car ran like crap so he took them back out.

 

[daren_p]

I would turn the boost down if I were you, you could be causing damage. Im not sure how many extra psi the 255 pump will allow but on the stock fuel system I was seeing 107% injector duty cycle at 15 psi. Your probably only getting away running that much boost as the 255 pump will over run the stock fpr, raising your base fuel pressure. As for hitting fuel cut, the first thing you want to do is check for boost leaks. You shouldn't run 550's without something to control them as you will run much too rich.

 

[DGajre777]

yeah i figured that it was to much for the injectors but will i be able to put the 550's in for the time being without either an afc or the fpr?

No, you cannot.

they guy who had the car before me said when he had the 550's in the car ran like crap so he took them back out.

Ofcourse it ran like crap. You can't just install bigger injectors and have no way of controlling them.

 

[madmike]

I am running 680cc injectors and a TurboXS Fuel cut defender.
you can buy those through here, you get linked to www.extremepsi.com

 

[90GSX17]

Well last night marked me shooting my first fireball, it was cool to say the least, but I have one question does fuel cut cause that, because I think I hit the rev limiter but not sure, because everything happened so quick, i've never popped flames before, but again I never hit the limiter. Was this just a case of a super rich moment, it was a fast 1st gear pull and then BOOM!

 

[CanadianTSi]

Sounds like you hit the Rev Limiter...

 

[billys90tsi]

Good news and bad news.. Bad news there is no rev limiter on the 1g's but u probably shifted with boost before it all blew off and hit the gas again i can do it on command in my gsx

 

[Irrational]

Good news and bad news.. Bad news there is no rev limiter on the 1g's but u probably shifted with boost before it all blew off and hit the gas again i can do it on command in my gsx

no rev limiter huh? thats news to me.

 

[Bo0O0ostedDSM]

Yea, my guess is you hit the rev limiter and things got too fuel enriched... then all that unspent fuel went boom!

 

[awd93talon]

is it possable to get fuel cut at 16psi with a stock turbo? if so what are the ways to get rid of it(chiped ecu or dsmlink) Right?

 

[DSMcamaro]

Yes its totally possible. Might want to run a boost leak first before you do anything else.
http://www.dsmtuners.com/forums/showthread.php?t=220786&highlight=fuel+cut
http://www.dsmtuners.com/forums/showthread.php?t=220786&highlight=fuel+cut
http://www.dsmtuners.com/forums/showthread.php?t=217815&highlight=fuel+cut

 

[awd93talon]

no boost leaks but how can i fix it. it happend at 5.5k rpms with 17 counts of knock, right when in happend

 

[daren_p]

Have you actually done a proper boost leak test? Or are you just assuming there are no leaks becasue all the clamps are tight etc. But yes Dsmlink will prevent you from hitting fuel cut.

 

[DSMcamaro]

SO HOW DO I PREVENT FUEL CUT?
This really isn't that hard. You have to SAFELY reduce the air the ECU sees. This means to deliver more fuel to the engine (assuming you are shooting for the right AFR) per air count. To do this you must increase the injector size (fuel flow per air count) and then use an new ECU program or AFC to decrease the air count accordingly.
taken from...
http://www.dsmtuners.com/forums/showthread.php?t=186971

 

[kylehlub]

I was getting fuel cut too. It turns out my gaskets were too old and was leaking boost. I replaced all the gaskets from manifold to the end of my exhaust and now I'm not getting fuel cut anymore. If you haven't done a good job of checking for boost leak, do it again.

 

[daren_p]

I was getting fuel cut too. It turns out my gaskets were too old and was leaking boost. I replaced all the gaskets from manifold to the end of my exhaust and now I'm not getting fuel cut anymore. If you haven't done a good job of checking for boost leak, do it again.

Exactly, 16 psi seems kinda low to hit fuel cut with the 14b. Thats why the first thing you should do is a proper boost leak test.

 

[chanley talon]

I read your mods on your car. have you been running 16 psi all this time and now you getting fuel cut all the sudden ? You can of course pull out you lower air foil . shouldnt hurt anything.