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

 

[DragSourceTsi]

Stock pump??

 

[Scott_S]

Does it just studder or is it like hitting a wall?

 

[majik2k5]

I think the title basically says it all. It was running a little lean for me for a week or two I riched up the mid and wot settings on the MAFT, and it ran a good bit better but I never actually got on it. The idle is richened up, too.

Is it possible that the car is running too rich and is too much for the stock fuel system? I haven't gotten a chance to lean it out a little bit and take it for a ride yet, but I figured I'd ask for input beforehand.

 

[4g63tsiawd]

I didn't see a upgraded fuel pump in your mod list, is it still a stocker. And how do you know you were running lean.

 

[airmail96]

When your car hit fuel cut does it shut off? If so you might want to check your injectors and make sure they are spraying right. My friend had a similiar problem and one of his injectors wasn't spraying right, causing him to run lean and blow a hole in his block.

 

[4g63tsiawd]

How did your first motor blow up.

 

[exiletalon]

My first engine overheated and blew! I am running the stock fuel pump, thats why my psi is down to 9-10 psi. I have a 190 lph and rewire kit waiting to be put in. Will a rewired 190lph walbro be good enough for a GReddy/mitsu 18G 8cm/ 14-16 psi. I also have a weapon R AFPR. Could these handle my 18G?

 

[exiletalon]

My car just feels like it hits a wall, and seriuosly bogs, so I let off, it didnt die when I hit the "wall."

 

[Scott_S]

Sounds like fuel cut to me.

 

[DragSourceTsi]

There is a rubber piece that the stock pump has around the outlet. That could be torn allowing fuel to flow past it. If you have the pump there I would try installing that.

 

[exiletalon]

There is a rubber piece that the stock pump has around the outlet. That could be torn allowing fuel to flow past it. If you have the pump there I would try installing that.

Could you please clarify that a little more, as i can barely understand what you are talking about. The outlet ( to the assembly?) or ( the outlet line?) or ( the outlet from the fuel pump directly?)

 

[exiletalon]

Would my new pump being installed fix the ripped rubber boot, or is it something I'll have to replace entirely seprate!

 

[Boost95]

Explain your situation a little better. I had gone thru everything when its comes to fuel cut. Does your car sputter or do you lose all power? If you stay on it will it buck violently?

 

[DragSourceTsi]

after i typed that I thought it sounded bad. How about a pic? i'm uploading now

 

[DragSourceTsi]

You must be logged in to view this image or video.

There is a rubber piece that goes where the circle is. I have had that tear or deform and then the fuel can run back by. I'm not 100% that the wall comes with a new one.

 

[exiletalon]

Explain your situation a little better. I had gone thru everything when its comes to fuel cut. Does your car sputter or do you lose all power? If you stay on it will it buck violently?

At around 4-4500 RPM I feel like Im nose diving, I lose like all power, so I let off. Its really annoying b/c i have never yet felt any real boost or power as I have never exceeded 4000 RPM. I have a new engine and manifolds, but the problem persisted even after the swap! The injectors are off of the new engine ( 450cc) and the only thing that was kept was the turbo, and I am still running the stock fuel system ( completely stock!) I have a 190,AFPR, RE-wire kit waiting to be installed. Will these help the issue, I also have a 8cm 18G waiting to be installed, But whats the point if i cant exceed 4000RPM!!!

 

[DragSourceTsi]

The pump should be installed anyway. Just go for it

 

[exiletalon]

The pump should be installed anyway. Just go for it

I have read many articles both here and VFAQ, is there any way that I can install the pump without cutting any lines ( I dont trust myself in cutting lines!) Also, I have difficulty understanding the seperation and "how-to" of re-using/cutting the spacers.
Sorry, I know its stupid. But I have never installed a FP before, I've always done mechanical stuff like installing a turbo or FMIC, or exhaust and intake stuff!

 

[DragSourceTsi]

I never cut any lines? Have a link as to what you are talking about?

 

[97_eclipse_gst]

I have been having the same problem that you are. I do not think that it is feul cut because i still have the stock t25. Does this happen in all gears or more often in higher gears? I have also been trying to figure this problem out i have spent over 1500+ fixing and changing everything and its still not fixed yet. Anymore input on the subject will be appreciated, i'll look at the list of thing i changed and checked to see if you have anymore luck.

 

[4g63tsiawd]

It doesnt sound like fut cut. Since it happend with both motors it sounds like a sensor or maybe your coil pack. Are you getting any kinda dummy code. Fuel cut feels like hitting a brick wall, or it will start backfiring and stuturing really bad.

 

[Scott_S]

Mine was fixed with a new o2 sensor and buttoning up all the boost leaks

 

[bigdogg2834]

The only real way to tell would be if you have a logger and you can pull a run, log it and see where you are at and where you need to make adjustments. Otherwise you are just guessing, which isn't good. If I was in your situation I would just zero out the maft and keep boost under 15 psi untill you get a logger and can see whats going on. And also, the fuel cut would be caused by you running too lean not rich.

 

[DragSourceTsi]

fuel cut doesn't know if your running rich or lean. It just means that something doesn't have the ability to deliver the proper amount of fuel anymore. Leaning it out would make less stress for your fuel system. With out a logger or WB it's hard to know.

 

[mavisky]

If you're still on stock injectors you're going to be stuck. The MAFT replicates a bone stock maf from a stock 1g dsm. You'll hit fuel cut with it just the same as you would without hacking the mas.

Leaning out the wot mode will push fuel cut further away, but will also make your car run leaner, and if you are still on the stock pump and injectors you'll be running dangerously lean at that point. Upgrade your pump and injectors then turn the boost up and lean the maft out accordingly, then you won't have to worry about that issue. With just 510's, a rewired 3000gt vr4 pump, and an adjustable regulator set to 45 psi base I could run as much as 21psi w/o hitting fuel cut on my MAFT. I never tried more as I was running out of injector and octane at those levels.