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

 

[92turbors]

Dieselboy, one more thing. Do your values fluctuate alot? Like your temps. Do they bounce from say 90 - 100 really fast or is it one steady number? Thanks

 

[KidintheTSi]

The only logs that I have saved right now apparently weren't logging my injector pulse; sorry. I'd go run some to find em out but I'm having what I think are head gasket problems right now and have my wastegate actuator disconnected to reduce extra pressure on it.

 

[92turbors]

Sorry to hear that. But was there noticable fluctuation in all your readings? What I'm trying to get at is all my values go up and down all the time. I am thinking maybe it's from a bad cap or alternator regulator (Though when the car is not running the values are still jumpy) I have about had it with this car!!!

 

[Dieselboy]

My air temps and coolant temps stay pretty pinned. The highest Ive ever seen my air temp was 121F and that was street driving on an 80+F day with the heater off. Now that its in the high 50's here in WA, Im usually right around 95F-100F with flux's between Street and freeway driving. Coolant temps are usually pinnned at 201F, but keep in mind I have Fluidyne Radiator and SPAL slimfan.

 

[PowerEclipses]

, Well, thanks guys on the more then I could read in my life about fuel cut post. I changed the gap of the spark plugs and seems to be running a little bit better now, I am also getting a fuel pressure regulator and EGT gauge coming real soon. So, I hope to get both of those installed real soon and start doing some tuning or as much as I can. The post changed pretty dramitcally but thats ok.

 

[splitsecond03]

how exactly can u fix fuel cut? how do u know what is makin the car run lean? how do u know what part to put in to fix it?

 

[BlackMage]

I know this has probibly been answered many times, but what is the best way to avoid fuel cut and also run an atomostphere bov opposed to a recirculating one. i was thinking about purchasing an apexi safc but i would like some other suggestions, i have a 2G MAF on my 1G eclipse also.

 

[laserRSawd]

hks vpc, its pretty expensive not worth it just so you can vent

 

[13secGST]

yeh...the AFC doesn't let you vent. You would need either VPC, Standalone...and I've heard of some people doing it with a GM MAS Translator.

Also Fuel Cut is something totally different, and is based on air flow

 

[BlackMage]

Well yeah i know they both have to do with airflow in one way or another thats why i asked. in the same question

 

[Jason84]

you can get a gm mas and get a blowthru upper pipe.

that way the maf is after the BOV and gets the reading of the air going into the engine not being sucked in. so you can vent.

 

[BlackMage]

how hard would that be to setup?

 

[DenverTalon92]

I shelled my turbo about a month back....pretty good too at that! well, I replaced my turbo last night and now i'm getting fuel cut above 3ooo rpm. and no, I did not upgrade to a bigger turbo, I replaced it w/ a stock TDo5h...nothing special. well, I already cleaned out all of my intake piping, dumped about a half a quart of oil outa my intercooler...got it all clean! got my plugs cleaned...everything is on and tight!!! but I'm still getting fuel cut, please please give me some advice!
thanks for any help!

Chad K.

 

[DenverTalon92]

I really need anyone's advice as to why i'm getting fuel cut. Like I said before, everythings in place...nothings left disconnected. I already cleaned my plugs. Its a stock TDo5h turbo. not pushing over 16 lbs of boost...it starts cutting around 6-9 lbs. anything above 3ooo rpms I get cut and its blowin black smoke. please please, ANYONE!!! give me some advice!

thanks
chad k

 

[AwdEi]

My car can't run more than 13 psi w/o gettin knock or fuel cut (only fuel mod was rewired pump). Not all cars can run 16 psi with only a rewired pump. Another guy around here can only run 13 psi, also. Its just one of those things.

Turn the boost down, or up your fuel system. If anything, get S-AFC I. They are cheap now and you should be able to adjust the fuel enough to run 16psi safely.

Hope this helps.

 

[AwdEi]

What are your fuel mods and how much boost are you running?

 

[DSMKid49]

get an AFC

 

[leet]

Are you running higher than stock boost levels? If so, lower it down.

 

[sirhcs 4g63]

disconnect your ground for about 5-10 minutes to let your factory ecu reset. then see if it's doing the same thing. i had a similiar problem after upgrading to a big 16g, but after resetting the ecu it works better now.

 

[awd_terror]

Might want to go with a colder spark plug. NGK offer a plug, its BPR7ES (I believe) it helped my car out. No need to get a S-AFC if you have no way of logging the car. Also, if your boosting higher levels, I would suggest a bigger fuel pump.

my $.02

 

[gsxtacy]

Alright all you dsm gurus, I have done my research on fuel cut and I understand what it is but It still isn't helping me problem solve my issue.

My very low modded GST: (Free mods, Cone-type air filter, turbo inlet pipe, test pipe, magnacore 8mm wires) is experiencing fuel cut at full boost, It is also idleing very shitty for a few minutes then smoothing out and running fine. My search turned up several people w/ the same symptoms but no solutions. WHAT DO I NEED TO CHECK OR CHANGE ON MY BABY!

 

[13secGST]

Originally posted by Eclipsed
Change your spark plugs. NOW. get some that are a range cooler at www.machv.com or pepboys. See how your car runs after that.

How is that going to?
A) Help with his fuel cut
B) Help with idling issues

It wont help with any of his problems
Fuel cut is based off air flow...some DSMs had it slighty lower than others...I had it when I got to about 25-26lbs/min airflow...now I flow about 31-32 since I have DSMLink.

DSMLink is one way to get rid of fuel cut.
Turning the boost down is another way
Getting bigger injectors and an SAFC is yet another way.

Are you sure that you hit fuel cut and not just your rev limiter at 7500rpms? Because with your mods you should be no where near fuel cut. Unless your trying to boost like 24psi on the T25...but I don't think the T25 could even flow enough air to hit fuel cut...

 

[gsxtacy]

Ok! I Have no boost controller of any kind so I am running on stock boost limits(about 12psi max). I have hooked up a boost guage but have already checked for vac leaks and found none. I regapped my plugs thinking maybe It is not fuel cut w/ no change(yes i reset my ecu). I am leaning toward a dirty fuel filter possibly and the idea about the bcs free mod sounds good but I preformed the free mods on my car about a year ago w/ no problems till now. My newest parts are my turbo inlet pipe and my boost guage.

Please keep the ideas coming, they are helping

 

[Airpoppoff]

so your positive your holding 12 psi to redline?


what kind of atmosphere are you living in?

 

[cOiL]

with those mods you might be boost spiking without a boost controller. like Airpoppoff said, you sure your not goin above 12psi? the stock boost guage is worthless.