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

 

[Smokin80]

ummm i could be wrong but i bet you have crank walk and your crank is hitting your CKP( crank position sensor) and causing you problems. I hope for your sake im wrong but i would def check that out.

 

[S_Ranger]

I'm not sure if it's fuel cut or power loss but when I get going, let's say going on 15 in first, the car seems to lose it's power and jerk but it only lasts for a second. It doesn't do this every time, but it does happen. I did the fuel pump re-wire mod so my guess is something is lose.. I checked the main ground and it's connected well. I'm out of state and I can't check wires and what not until I return the 22nd. But if I can get some help it will prepare me when I get back. Thanks enthusiasts.

 

[talonracr19]

Fuel cut how I experienced it, did it more than once in a given pull. Well if it would last any more then a second, it could be a knock sensor, ### if they are faulty, it'll make the car fall on its face. Are you running more boost then factory settings? And what all perf parts are on that, to get an idea what we're or everyones workin with.

 

[S_Ranger]

No MBC so I'm running a psi below stock boost settings on t-25. The 1 psi lost is due to my FMIC. I plan on upgrading the turbo this month but I'm wondering why this happens. I'm gonna go do a search on these knock sensors because I'm not too familiar of their job.

 

[Laysher91]

I have a 1g that had similar symptoms TWICE on seperate occasions and both times it was a bad TPS. It was always at the same rpm (3.5k for me) no matter what gear and it was a violent-random-bucking affect. The first time it happened, it threw a CEL...BUT the second time it happened it didn't-but changing the TPS solved the problem. I usually pick used TPS up from ebay; the most ive ever paid was $15 including shipping. Its not much but its worth a shot if your TPS is questionable. Hope this helps and feel free to ask any questions.

 

[S_Ranger]

Ok, how can I check it and what do I look for? I need all the 'might be' answers and instructions on fixing it I can get. Thanks dsm'ers.

 

[bluetlr2001]

You may want to try a boost leak test while your at it. That will cause it to hit fuel cut early also. It builds boost so quickly that its leaking it out so the ecu is adding fuel for air that isnt there.

 

[S_Ranger]

Alright guys, thanks for the replies. I'll check back in when I get home saturday and post some results. If anyone has something else to throw in feel free.

 

[bob123131]

Do a quick boost check first. Half of all fuel cut problems can be related to a boost leak. Unless you happen to have a huge turbo and be going 160. Then its ###### normal fuel cut

 

[chanley talon]

I'm leaning towards the TPS being out of adjustment!! But you might see if your BOV is leaking as well.

 

[deadlyforce]

I have had my car since last October, and I've hit fuel cut about 6 times. At least, that's what I believe it is.

After doing some research, tell me if I'm right, while cruising along, about, 1/4 to 3/4 throttle (it's been varied), and all of a sudden, the gas pedal loosens, and allows me to rev the engine to WOT, without moving forward at all. I release the pedal, and can rev about three times before I feel the car engage, then everything goes back to normal.

This nearly caused me an accident yesterday, as I was doing 70 on the highway (speed limit is 70) and I just dropped down to 55 right after an on ramp, and picked back just in time to see the truck behind me flip me off and honk his horn, nearly rear ending me.

I am going to change the fuel filter this weekend, but is there anything I can do while I'm out there to ensure that this happens less frequently?
Thanks in advance.

 

[The_EE]

After doing some research, tell me if I'm right, while cruising along, about, 1/4 to 3/4 throttle (it's been varied), and all of a sudden, the gas pedal loosens, and allows me to rev the engine to WOT, without moving forward at all. I release the pedal, and can rev about three times before I feel the car engage, then everything goes back to normal.

I think the problem might be more then fuel cut. Check for boost leaks.

 

[JayRolla]

Ok your car is completly stock so im pretty sure your not fuel cutting. Plus you are a 2g and you have to run quite a bit of air to get the 2g maf to fuel cut. Im almost positive its not fuel cut. I dont know but it sounds like what a automatic tranny does when it starts to slip and go out. Are you auto or manual?


P.S. Fuel cut feels like you motor exploded almost like a huge misfire. It feels like hitting a brick wall. What you explain is not fuel cut from what I have experienced.

 

[Killa_dsm]

Ok your car is completly stock so im pretty sure your not fuel cutting. Plus you are a 2g and you have to run quite a bit of air to get the 2g maf to fuel cut. Im almost positive its not fuel cut. I dont know but it sounds like what a automatic tranny does when it starts to slip and go out. Are you auto or manual?


P.S. Fuel cut feels like you motor exploded almost like a huge misfire. It feels like hitting a brick wall. What you explain is not fuel cut from what I have experienced.

Yeah like Jay said, I dont think its fuel cut. It sure doesnt sound like it from your description. You should check your plugs and change your fuel filter. But we need to know more info. It also sounds like your clutch could be slipping..

 

[JayRolla]

Oh yea duh!!!! I bet your clutch is slipping. Ive had an auto go out lately and thats what it did.

 

[chuckg]

Yeah mos def not fuel cut. Fuel cut is terrifying the first time it happens . Sounds to me like a clutch too. I had a 3kgt with a slipping clutch and it would rev up and down and not speed up at all, espically at high speeds...its really strange.

 

[Dsmwant2b]

Do 1gs have a actual fuel cut and would a SAFC get rid of that or will I need a FCD or DSMLink?

Steve

 

[CanadianTSi]

Do 1gs have a actual fuel cut and would a SAFC get rid of that or will I need a FCD or DSMLink?

All DSM's have fuel cut, which is caused by the ECU seeing too much airflow.

If your S-AFC settings were in the Negative then yes that would cure FC, and both the FCD and DSMLink can rid you of FC.

That being said, Most cases of FC are caused by a boost leak.

 

[deadlyforce]

It's an automatic. It did it again to me tonight, and scared the shit out of me. I was going slow in a 25 zone, but there was a cop behind me. I got pulled over because he thought I was drunk when I slowed down and sped up like I did.

 

[JayRolla]

Oh I called it, just a lucky guess. Does it feel like its not going and if you rev it up the tranny grabs and it starts to go. Check your tranny fluid and make sure its full.

 

[deadlyforce]

Ok, I will check the fluid in the morning...then what?

I'm not a car guy, or I haven't been in the past, as I'm just starting to get into this. What could this possibly mean? A slipping clutch in an automatic...dear lord that doesn't sound good. So if the fluid is normal, what should my next steps be? And if it's low, which I know it shouldn't be, what do I do then? I have no money...any suggestions?

It first did this to me back in November, and it's been doing it more frequently since then. Is there any preventitive things I can do now...as to what I can do to stop it from happening, or what I can do to...I don't know, not have to get my tranny rebuilt very soon?
Thanks.

 

[DGajre777]

More info here...
http://www.dsmtuners.com/forums/showpost.php?p=50438474&postcount=9

 

[S_Ranger]

BOV is welded into custom 2 1/2" IC piping. but I just got back so I'm gonna perform these tests and post results...

 

[deadlyforce]

So wait, how can it be my clutch if it's an automatic?

 

[deadlyforce]

My transmission fluid was fine, just above the Hot line, actually on to the dipstick itself. It was clear, and the right color, so I'm sure it's not that.
Any more advice on what it could be?
And please explain the clutch in the automatic thing...