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

 

[mephist0]

the boost only goes up to 10psi

 

[mephist0]

you see but the damn chip is burned so it Eliminates the Fuel Cut I dont get it, and on the stock boost gauge is set for knock sum and when the car does the fuel cut, it the gauge goes up, I don't know,I got too much to learn still thanks

 

[95TalonOwner]

Obviously if you are hitting fuel cut, then the chip isn't programmed to remove it.

 

[JohnCIV_Talon]

Well are you sure it is fuel cut? What does it feel like.

 

[fallenauthority]

Hitting a big spike of knock can feel like fuel cut to someone who has never felt it before.
When timing is drastically pulled back the car will feel like its lurching forward a bit. If it is actually fuel cut, try a boost leak test.

 

[mephist0]

Hitting a big spike of knock can feel like fuel cut to someone who has never felt it before.
When timing is drastically pulled back the car will feel like its lurching forward a bit. If it is actually fuel cut, try a boost leak test.

what is the cure for "a big spike of knock" ?? I also have problems with the alternator, because when the lights are on the gauge panel and lights all dim like if the power was regular then low regular then low, something like this RRRRrrRRRrrRRrrrRRRrrrRRR hehe, thanks, guys for all of your comments.

 

[Dream On]

Boost leak test. Get a logger/DSMLink. Check your grounds and alternator belt tension.

 

[justin_5585]

Does the boost go to ten psi on the stock gauge (which is a joke), or do you have an aftermarket? Is it a stock turbo, as 10 psi on a 14b is way different than 10 on T70. Also, is your turbo back connected to a stock o2 housing, if so, you could be getting ruthless boost creep, as the 3 inch exhaust lets the turbo outflow the wastegate.

 

[jking29]

Boost leak test. Get a logger/DSMLink. Check your grounds and alternator belt tension.

X2!

 

[mephist0]

it goes to 10 psi on an aftermarket boost gauge, and I got a tubular o2 housing from punishment racing I think it's a 2.5 o2housing, and I got the evo 16g ported on the side where it connects to the exhaust mani, so you think I might be getting boost creep????

 

[justin_5585]

To run that low of boost on an evo3, you'd have to port out the hot side, and probably install the 34mm flapper door. So when you put the hammer down, the boost sits at 10 psi all the way to redline? Watch your boost guage when you hit fuel cut, and see where it is at. Where did you get your chip for it? You're sure it's setup for 550's?

 

[mephist0]

I got the chip at dsmchips.com but to tell you the truth the aftermarket boost gauge sits at 10psi all the way, when the car hits fuel cut, then the stock boost gauge goes up, and it was set as a knock gauge from dsmchips.com I might end up getting the 34mm flapper as you told me to see if that helps it thanks

 

[mitsclipse99]

ok so I have a 98 gsx... guy who owned it before me put a evo3 16g on it and a k&n FIPK on... not sure he went with fuel mods... After I got the car, I bought hard greddy piping with hks bov, then espelir jgt500 exhaust. When I'm driving... I put it down in 2nd and hear the turbo spool then after I look at my guage and see like 4 psi... my body goes forward as if I hit the brakes. Fuel cut? at 4 psi? wtf is goin on! thanks for any help guys/gals!

 

[alex99gst]

Are you asking why your car jerks forward when you downshift? If it doesn't normally cut out at 4psi, then no, it is not fuel cut. These people are experiencing fuel cut when they get on the gas, not downshifting.

 

[mitsclipse99]

no.. didnt say I downshifted, sorry to clarify that - I take off from a stop, shift to 2nd then step it down, the turbo spools then nothing, it jus feels like I hit the brakes really hard.

 

[alex99gst]

no.. didnt say I downshifted, sorry to clarify that - I take off from a stop, shift to 2nd then step it down, the turbo spools then nothing, it jus feels like I hit the brakes really hard.

This can't be stressed enough. Have you done a boost leak test?

http://www.vfaq.com/mods/ICtester.html

 

[mitsclipse99]

yes sir I have. Found that my throttle body gasket was shit so I replaced that, then the BISS screw was also leaking (that I think is fixed by a rubber o-ring if I'm not mistaken) I have checked the WGS, seems to be hooked up correctly still, just kind of confused!

 

[oldman]

yes sir I have. Found that my throttle body gasket was shit so I replaced that, then the BISS screw was also leaking (that I think is fixed by a rubber o-ring if I'm not mistaken) I have checked the WGS, seems to be hooked up correctly still, just kind of confused!

How much pressure were you able to register on the boost gauge during the pressure test after you fixed those two leaks?

 

[mitsclipse99]

First and foremost, sorry for the inproper grammar/ spelling. To answer your question, I only pressurized the system to 14 pounds just to be on the safe side (trying to keep boost levels down for now.) Should I try and pump more into it?

 

[oldman]

First and foremost, sorry for the inproper grammar/ spelling. To answer your question, I only pressurized the system to 14 pounds just to be on the safe side (trying to keep boost levels down for now.) Should I try and pump more into it?

If that is the case, I seriusly doubt that it was fuel cut you experienced unless you have either a defective ECU or MAF. Fuel cut is an extremely violent event, the first normal reaction after fuel cut is to look in the rear view mirror to make sure your engine hasn't drop out of your car. I suspect what you're experiencing is bogging, which can be cause by ignition or improper AFR.

 

[DSM90AWD]

Is your BOV "venting" ?

 

[mitsclipse99]

Nope, I have the blow off recirculated. I'll try new plugs and wires this week sometime, if thats not it possible coil pack?

 

[boostedtsi0069]

Hey i dont know if this is fuel cut or not. Im on third or any gear n i floor it it piks up nice but when i feel the power really getting there it'll hit a wall then instantly go again and thats back and forth at high rpms until i switch gears. I tried half throttle till redline n it dont do it its only at WOT. Can anyone tell me what it is, anyone experience this? And if so what was the solution? Thanks guys

 

[92dsmtalon]

Sounds like fuel cut. How much psi are you running, are you still running factory injectors and fuel pump?

 

[SOADweskey]

Check the condition of your spark plugs and their gap. I had a similar problem and $10 on a new set of plugs gapped to .028" fixed it right up.