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

 

[twenty5psi]

if your going to upgrade to bigger and better anyways later on then now would be the time to try a bigger fuel pump and a rewire since this problem is plagueing you right now..

 

[unior]

this should be obvious to you but check for big ol boost leaks

my 2g was fuel cutting like a bi*** @ 12psi

i had a big leak in my supra smic and the 2g bov was leaking and attributing to it

 

[tsi_turboawd]

ill tell him look into any intake leaks. He crushed his 1g bov so it shouldnt be leaking out there to cause fuel cut.

..and i told him to upgrade his fuel pump to 255 anyway

 

[TalonTSi-AWD91]

Hey everyone, I'm having a problem with fuel cut, but I don't think I should be. When I'm driving as soon as I hit about 5,500rpms the car hits fuel cut. Also if I just cruise or let off the gas the car feels like it's missing or it's getting like a 50rpm idle surge I guess. Problem is I'm at stock boost right now. The only mods I've done is an upper and lower intercooler pipe, K&N, and removed air can. I've changed the TPS, spark plug wires, spark plugs, tried a different MAS, and checked for leaks. I did find a decent leak, fixed that, but the problems still there after everything. I've checked for error codes and get none at all. When I changed the spark plugs, they were white, which I don't know if they should have been or not cause they've only been in the car since january if I remember right. I'm going to check the coil pack and CAS just to be sure, but what else could be the problem?? The car was perfectly fine, then I changed the oil in it, car was still running perfect. A few minutes after I changed the oil I went to the car wash to clean the car up and it was fine on the drive there. After the car wash, the car seemed fine till right before I got home and I started noticing the missing when letting off the throttle. Didn't drive it the next day, then the day after when I drove it, this all started. Also, I don't know if it'll make a difference, but it'll buck at around 5,500rpms anytime, when the cars cold or hot, but the missing doesn't happen till after the car warms up. Thanks for your help, and sorry it was so long, but just wanted to make sure I covered everything.

 

[EHeye]

i dont think its fuel cut bud, at 5500 rpm is when the stock 14b drops off, ie no power.

 

[TalonTSi-AWD91]

It's not like I'm just losing a little power, the car feels like it's hitting a brick wall.

 

[EHeye]

yah bsically thats what it feels like, nothing left, thats cause you think about it your going from boost to basically nothing, try rewiring the fp and test the voltage through your car, your caps may be leaking a bit making voltage off taking alot of power away from the fuel pump.

 

[TalonTSi-AWD91]

Forgot to say that I also have already checked the ECU caps, they're fine, and I looked at the exhaust manifold and theres not a single crack in it. I think that my alternator is going bad also. It's been like that for a few months, maybe that could be the problem. There was one time lastnight that it felt like it slammed into a wall at around 4,000 rpms. Only time it's done it that early though.

 

[tsi_turboawd]

my buddy is having the same problem.

try:
ECU, FPR, Injectors-clean them, hack/swap MAS, check for intake leak, replace fuel pump and get a walbro 255 unit

good luck

 

[xxdalexx]

i have a 99 gst and have had my motor rebuilt. when i push the gas hard and left off the car is fine but when i dont let off and just push hard my motor "studders" i have broken in the car and dont know if it studders because its to lean or not getting fuel

 

[Ðawg]

Fuel cut sucks... the first time I hit fuel cut, it was like someone picked me and my car up, and threw us back down on the highway...


And as one member stated, time to pick your teeth out of the steering wheel.... man, that is the truth!

--Scott

 

[unior]

my god damn car is now fuel cutting at 4krpms or less all the ####ing time. I'm so pissed right now

 

[RedGSXburnout]

wow these dsm's are fun hey

 

[talontsi01]

Im getting fuel cut right now on my stock fuel system and stock 1G maf. If I replace the maf with a 3" GM maf and the Ramchargers MAFT, will I run into fuel cut still?

 

[unior]

well today i tore every fricking pieve of my intake out and and individully pressure tested each part alone.

every thing tested ok so i put it all back in, made and installed block off plate for my egr valve - took her for a spin and poof a connector had blown off


back to garage, reclamp, add hairspray to connector

tada no leaks no fuel cut!

 

[DRAG_ON1]

hey , when I am driving a consistent speed it feels like my car is turning the fuel off and then on. You can barely feel it. Or is it idle surge. When I drive in second gear at about 20 mph the car starts to buck alot.

I have done all of the free mods and 3 inch exhaust.

 

[LightningGSX]

You'll know it when you get fuel cut, it feels like you hit a wall.Check your plugs and wires.

 

[Drifte]

i feel the same prob, but its usually when i floor it. i need some input as well

 

[Timberwolf]

Could be intake leak. Have you crushed your BOV?
I recall having to swap ECU's to solve my problem similair to this.

 

[DRAG_ON1]

I have done plugs and wires last week. My car idles up and down some times.

 

[DRAG_ON1]

my bov has not been crushed. I heard it wasn't a very good idea.

 

[Turbo92Talon]

veh: 92 dsm awd
mods: 255 lph fuel pump, stock injectors
- new small 16g turbo ported
- new 95 ported exhaust manifold
- new 3" turbo back exhaust w/ 3" d/p & O2 housing
- Turbo XS manual boost controller
*
problem: boosts 13-15 psi till 5k rpm then as the rpms rise the boost rises until 6k where engine hits fuel cut & 20+ psi registers on the boost gauge
*
I'm not real sure what causes this nor how to combat it....
any ideas or thoughts would be greatly appreciated... I'm new to the game (DSM) & have been told that this is boost creep...what do I do??
TIA for your asstance...


Kevin

 

[benchandler]

I think this is a problem with our POS turboxs boost controllers, Try to set yours with the brass side almost all the way in and the "blue" screw almost all the way out. (assuming you have the high performance mbc) Im in the middle of fvcking with mine right now,
www.dsmtuners.com/forums/showthread.php?s=&threadid=62795

let me now if you figure anything out. I actually think this creep is to do with our mbc's not being able to hold pressure.

 

[rebuilt65]

16G's are known to be creepy. Did you have yours modified with the 34mm wastegate flapper? That's a good fix. Also, I heard that 3in DP's can contribute to boost creep. Hope that helped.
regards

 

[THEDUKE]

If you set the boost controller up that way it will go full boost. They are bad for the ball sticking. But for setting take the boost controller off the car & set the course side(brass side) back it all the way out. This would be to your right & then start turning it in (to your left) and shake it and listen for the ball to rattle. Keep turning it in untill the ball stops rattling. this is a good point to start from. I go about one more turn past that but start from there. Then take the fine side (blue side) and turn it all the way in to bottom(to your right). Then back it out 4 turns & try it from there. Also the line from (Vac or Boost) works better if you come from the intake instead of the throttle body& use as short of vac lines as you can & use good line not soft line. If the ball does not rattle when you are ajusting the course side the ball is stuck & you can take the brass side apart & clean & add alittle graphite.Also the blue side has a oring that can start leaking. Pull the screw out of the blue side and see if the little oring is good & lube.