Fuel Cut: What is it? How do I fix it? [merged]

Slanted J · 04-17-2002, 10:23 AM

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

Red91AWD · 07-04-2002, 05:25 PM

In 3rd gear at 3000rpm, the car begins to hesitate and shudder. I can hear the turbo spinning and boosting way too much,very loud. I'm not sure if could be the wastegate or maybe the fuel cut is on because of the wastegate malfunction but I wanted any more helpful hints. The motor is strong with no smoke and with out a load it revs up fine but after driving it and hitting 3rd gear, it just starts.

it has new plugs,O2sensor,gaskets,hoses,..etc tuneups

LethalEagle · 07-05-2002, 11:17 AM

That does not sound like fuel cut. You would definitely know if it was fuel cut. The car would not shutter at 3000 rpm. It usually hits at about 5000 and it's like hitting a brick wall. It could be anything from the clutch slipping to a lack of fuel flow or a lack of voltage flow..... Have a shop put it on an oscilloscope, that usually finds the problem quickly. I thought my wires were new, but I found out there was a burn spot from making contact with a hot area under the hood. The oscilloscope found it, Good luck...

Blown 2.0 · 08-24-2002, 01:57 PM

I had the same problem a while ago.Turned out to be spark pluug wires.

NeEmO6 · 08-25-2002, 07:16 PM

plugs and wires for me caused the problem.

rpmvulocity · 09-07-2002, 09:20 PM

Okay I have a problem. I know some of you DSMtuners may have the same exact problem so I'm just trying to get mine out. Well, my question is how do i stop my car from hitting fuel cut? I went and bought an HKS fuel cut deal that makes it so it wont hit fuel cut, but my car still does. I top the car out at 140mph with fuel cut and I wanna know how fast my car would go with the damn thing hitting fuel cut. I'm pretty sure i hooked up the HKS thing right into the ECU. So now I'm stuck how to stop the motor hitting fuel cut. If anyone can Help, thanks.
-Rpmvulocity

turboholic · 09-07-2002, 10:10 PM

Here .

dave99gst · 09-08-2002, 11:41 PM

i dont think your talking about fuel cut - ya sure you aint hittig the rev limit?

rpmvulocity · 09-09-2002, 12:49 PM

I'm pretty sure it's the fuel cut because i can jus feel it. If my car was hitting the rev limit it will hit the rpm and jus stay there for awhile and rev in high RPM but it seems like it jus laggin so im sure it's hitting fuel cut.

masterpah · 09-24-2002, 12:15 PM

I have a 97 GS-T, with stock fuel. At what RPM does the fuel cut occur.

cucumber · 09-24-2002, 01:04 PM

And trust me, you'll know it when you feel it

ChadH06 · 09-24-2002, 05:03 PM

I Havent seen anyone ask this question yet, sorry if someone already has but, I have a 1990 GSX with an ACV Controller removed airbox and exauhst system... I have been hitting 15-16lbs of boost acording to my aftermarket boost gauge. which is all good and dandy but just about the time I hit 16psi, I get that HORRIBLE FUEL CUT "BUCK"

Does ANYONE know of any cheep fixes to get around fuel cut or even if its not cheap what i need todo, i hate being limited from my cars true potential that I know it is capable of if it would hit fuel cut. Thanks DSMers

ChadH06 · 09-24-2002, 06:00 PM

any suggestions on new injectors and pump and afc? also is it possible to totally avoid fuel cut besides turning down boost, because we all know as DSMers, BOOST=SPEED

Beemer · 09-25-2002, 09:31 PM

It is not necessarily caused by running lean. Lots of folks get fuel cut in the midrange (2800-4400 rpm) because the ecu senses that TOO MUCH air is going into the engine for that rpm, load, and throttle position. The ecu intentionally runs the entire powerband rich. But the airflow meter says to the ecu...hey, I have 500 cfm going by me. The ecu says...hey, that's too much air...the bov or the wastgate is stuck and the boost will destroy the motor...lets slow things down a bit...
contact these guys at http://www.technomotive.com. They are the best dsm ecu gurus around and can explain it way better than i can. BTW, a stock engine can be made to hit fuel cut with free mods.

masterpah · 10-23-2002, 10:30 PM

I just hit a fuel cut the other night. I run a 16G with a VR-4 BOV and K&N Intake. I tool the car up to about 3500 rpm's in the third, and then just stepped on it. At about 4000 rpm I hit a fuel cut. I looke in the mirror to see if my tranny was behind me. Now I'm worried to take the car above 3000 rpm's. I couldn't find a fuel cut defencer for a 2G. Does anybody have any ideas. This guy is selling me a HKS fuel cut defencer, but the instructions say it fits 1G turbo eclipse. Please help.

masterpah · 10-23-2002, 11:18 PM

This is the first time it happened since I had the turbo upgrade (about 4 months). Would a bigger pump be sufficient cause I don't have the money for new injectors or s-afc. What about some kind of fuel cut defencer.

LaserRST · 10-24-2002, 08:30 PM

Be careful with the FCD. If you are running into problems with feul cut and you have no feul management than gittin a FCD may ruin your engine. Start with feul management, set boost levels at conservative levels. The 16g is a high effeciency turbo that can likely boost hard and blow an engine, heck the 14b's can do serious damage by itself. Save up for some sort of feul management sys, and your buddys FCD wont work on your car, he has the k3 if he owns a 1g, you need the standard according to the HKS website.

masterpah · 10-24-2002, 10:06 PM

What is the cheapest form of fuel management for a 2G, and the only FCD I could find of hks' website was the one for a 1G

LaserRST · 10-24-2002, 10:25 PM

safc is the most tunable and userfriendly for its price. You can go wit some used fcon units but it still not as tunable as the safc. HKS lists its three diff models, 1g DSM/supra, RX7, and everything else falls under standard. I would call HKS to confirm this to be sure.

GatorManTSI · 11-09-2002, 11:26 PM

Ok, I have an upgraded fuel pump, to go with my mods. When I go into 3rd and punch it, she starts to jerk.......again! Why is this happening? Could it be because I don't have upgraded injectors and S-AFC? Thanks for any input!

madmax · 11-09-2002, 11:48 PM

Jerks? From what I've heard fuel cut is like hitting a wall, your car basically just shuts down the fuel supply. Did it do anything similar before you upgraded the pump? check your plug and wires. Maybe a better description will allow others to help you better

GatorManTSI · 11-09-2002, 11:54 PM

It did this before the upgraded fuel pump, only worse. What it feels like it's doing, is choking, or pardon the expression.....coughing. I have new plugs and 8.5mm Magnacore wires. The harder I press the gas, the more it does it. When I slowly hit the gas, it doesn't do it. The jerk's are pretty rough, and begin around 5k rpm's. Very frustrating. Is that a better description?

wishihadatalon · 11-10-2002, 02:27 PM

i don't think its fuel cut b/c i have had it before. it hurts like a biaotch. when you have it you know it. you look in your rearview for your tranni. you might just have dirty fuel injectors.

jay-d · 11-10-2002, 06:56 PM

uhm.. thats happening to my car when im cruising, new injectors, new fuel filter, new plugs/wires.. the only thing my mechanic can suggest is.. coil pack.. the engine not getting spark when it needs it.. so thats why im replacing next.. =\ and if it fixes it, that might be ## problem too.!

HyperGSX · 11-10-2002, 11:22 PM

Sounds like it's an ignition problem...i think a DIS-2 is in your future. My car suffered the same symptoms that you described until i threw in the DIS-2...I pull smoothly to redline now.

Goblin · 11-18-2002, 09:57 PM

Umm, no... it isn't fuel cut...

My best guess is that you aren't getting spark of fuel. Do a spark test. The bad fuel pump is a good call, but before you go trying to get that pain in the a$s out of the tank do a spark test.

Best of luck.

90tsiawd · 11-20-2002, 11:47 PM

its in the computer. if you were to take the computer out i would bet the caps are leaking. hate to say this but i would start looking for a computer or send yours out to be rebuilt.

GatorManTSI · 11-21-2002, 02:20 PM

Okay, I pulled my plugs to check the gap. I saw on a thread from LarryD that he was having basically the same problem. Someone suggested pulling the plugs and changing the gaps to .26. So, I pulled my plugs. Low and behold, 2 were set at .26, one at .24 and one at .28. So, I fixxed the gaps on the other 2 to have .26 all around. WHOA BABY!!! What a major difference. The car drives smooth, no more jerking, AND that annoying ticking sound when it's cold, is gone!!!! WOOOOOHOOOOO. Now it's time to crank up da boost!! Thanks DSMTuners!!!!

talon400tsi · 11-24-2002, 12:46 AM

First Check all sensors to make they are working correctly. There is no way to get rid of fuel cut by just changing fuel injectors , fuel pump , fuel pressure, adding a AFC ect...The reason being the ecu is preprogramed for a certain amount of air flow and fuel. You can do a 2G MAF swap that will help a little because it flows more and is able to meter it better. You also could have the ecu reprogramed (TMO or JET do that ) but that does cost about 300-500 dollars. The cheaper alternative would to to add a FUEL CUT DEFENCER on HKS sells one BUT it cost 150 dollars . I made my own for LESS THAN FIVE DOLLARS. Cheap and effective. Make sure everything else is working correctly BEFORE you try tis mod . If you have a A/F gage and it shows you are running on the rich side, you have upgraded fuel pump with pump rewire, than this mod should fix the problem....

uva207 · 12-02-2002, 07:52 AM

I have a 95 GST, and I recently purchased a Hallman MBC. It has been woking fine, until at around 12-15 psi, my car stutters and hessitaes and the boost jumps to 23-30 psi?? I have no idea what this is. I tried taking off the MBC, but it still have the same symptoms. I then took it to my mechanic and ran a diognostic on it and it said there was a vacume problem. We checked the lines and couldnt figure it out. When it hapend the A/F ratio is very lean...
Please help me with this I have no idea what to do....
thanks