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

 

[JBDdsmer610]

Well i dont know if its worth it now i just spotted oil spots in my overflow and when i took my rad cap off. and the coolant is like a brow color and i just changed it.

 

[JayRolla]

Uhh thats not good at all, sounds like a blown head gasket. On some v8's that could be a cracked block, never heard of it on a 4g63. Also could have crack in head.

 

[oldman]

Porting you have about a 35% chance to fix it with just a port job..

Speak for yourself.

JBDdsmer610, there are two issues here.

1. Boost creep, options already covered. http://www.dsmtuners.com/forums/showthread.php?t=186525

2. Fuel cut at 14psi/4200 rpm = boost leak test.

 

[cHz]

i've been running stock boost(9-10) for a while now, just cause it's my daily driver and work car. i went to turn it up to about 14ish last night and i hit fuel cut in 1st and 2nd gear so bad, i almost hit my face off the steering wheel. i've run 20psi before at the track and absolutely no problems. i have no idea what the problem could be. one of my friends said it could be a bad boost leak... would that cause this? is there anything else i should check?

 

[JayRolla]

Yes, the main reason to hit fuel cut at 14psi is most likely a boost leak. How did you run 20psi on a 1g maf without fuel cut?

 

[JBDdsmer610]

I have done a boost leak test nothing leaked. I just noticed that there was oil floating in my overflow.

 

[boostedtsi0069]

Is your check engine light on?

 

[fourreGsixty3]

Boost leak test it.

Dustin

 

[cHz]

no, my check engine light is not on. my bov is vta if that means anyhting, but that's how i bought the car and haven't gotten around to doing it, but when i ran more boost it was vta then too, so i don't know.

 

[fourreGsixty3]

Recirc. that BOV. Do a boost leak test, fuel cut is from too much air.

Dustin

 

[viprez586]

I want to start by saying i know this has been covered plenty of times but i feel this question is a little bit more specific to my talon.
1. Cold Start-up is rough, like the car is congested and needs a little blip of the throttle to idle properly cold around 2k. After its started, it surges until warm. The car also runs like crap until normal operating temp.
2. Sometimes during light/mild accel the car will read boost but lack a considerable amount of power. I usually fix this on-the-go by letting off the throttle, and then acceling again.
3. under WOT 5.5k-6k fuel cut

i have a mbc set at zero so im running stock boost, and im running the dejon UICP and LICP.

any input would be great help. thanks

 

[ndsti]

Mine does something like that when its cold out. Just the other night my car through a CEL p1103 ( Wastegate Actuator Manfunction). So im thinking that was caused by either two things the BCS or the wastgate it's self. My car also surges, so check what i stated above. As for the fuel cut, happens to me but I can't explain it , maybe many problems. Hope this helps

 

[90ttsiawd]

Alright. So i got my front mount on, and my 3" downpipe and exhaust. Didn't have any kind of problems with fuel cut like i thought i would. So today i put my GM maf and maf translator on and now around 5k rpm it feels like i'm hitting a brick wall. I have a stock fuel system so i have to translator set on stock injector size. I made no other changes to the other three knobs (idle, mid, and wot). I'm running ten pounds of boost. Whats happening?!

 

[dsmclipse97]

Did you do a boost leak test?

 

[90ttsiawd]

Yeah, there are no leaks.

 

[Turbo96DSM]

try adjusting your wastegate actuator
did u adjust it at all when u put the turbo on?

 

[95blackGsTurbo]

try adjusting your wastegate actuator
did u adjust it at all when u put the turbo on?

That makes no sense. He is trying to fix a breakup around 5500rpm. I would get a fuel pressure gauge and see what your pressure's are first. Also check your o2 voltage on your SAFC, I'm assuming that is what you are using, and see if they fluctuate like normal.

 

[silvah_gsx]

If your mod list is updated, I see no upgraded fuel injectors. Did you add new ones? If not, there's your problem -- you can't run 22 psi on stock injectors, and when you lean out the AFC to compensate for the injector size, you also keep the ECU from thinking it has too much air and triggering fuel cut.

 

[matt j]

im having a similar problem with my car 95 gst with a 14b on it. But i have a bad front o2 sensor and a open dp. Once i figure out my problem i will let you know and maybe it might be the same

 

[SloCelica]

ttt, i'm having the same issue...no leaks, stock fuel system. any ideas?

 

[Quasimondo]

If there are no leaks, then the only other cause of your fuel cut is running too rich. The translator is giving the ecu a high karmen count, which is enough to trigger fuel cut. Although you have it set for 450cc injectors, many people will tell you that their settings are different than what the instructions suggest.

If you don't have a logger already, get one. After that, set your translator up using this tuning guide.

 

[domthebomb11208]

I have a 1990 1g awd. It has a 14b turbo basically all stock except open downpipe. I just bought a boost gauge and a boost controller everytime i try to run more than wastegate boost i hit fuel cut. I tryed checking for boost leaks and it was all good. Can someone help please?

 

[No_Skillz]

How did you try? Compressor and soapy water? What were the results?

 

[Rex2342]

I'm just curious but why did you switch to a Gm maf if your still on the stock fuel system?

 

[domthebomb11208]

i diddn't do it with soapy water...but i didn't hear anything