Fuel Cut Help!

[95undrpsi]

I just got my 6bolt swap running good yesterday. I took it for a drive to see if everything is working right. I gave it gas and it hit fuel cut every time it hit max boost(15 psi). I was running no exhaust at the time and my mod list is in my profile.

 

[slugsgomoo]

i don't see fuel mods in there, so....

With *no* exhuast on an internal gate you were probably creeping like CRAZY.

were you using a logger, or did it just "feel" like fuel cut? If you aren't logging, it's quite possible that you are ending up with so much boost (and such a hot intake charge) that you are knocking like crazy and pulling all of your timing. (though i suppose fuel cut is possible in that case as well).

I would suggest putting your exhaust on, and getting a logger. It's all a guessing game until then anyway.

 

[CanadianTSi]

Most likely a boost leak.

 

[talon96tsi]

im having a similar problem i think, my car cuts out momentarily for just a second during wot or hard acceleration, but then continues accelerating. but it does this lik 6 or 7 times sometimes. is that just a boost leak?

 

[95undrpsi]

It is taking my 14b pretty damn long to spool, so it is proably a boost leak.

 

[CanadianTSi]

im having a similar problem i think, my car cuts out momentarily for just a second during wot or hard acceleration, but then continues accelerating. but it does this lik 6 or 7 times sometimes. is that just a boost leak?

Could be a boost leak, or your plugs/wires could be bad.

 

[95undrpsi]

my car cuts out momentarily for just a second during wot or hard acceleration, but then continues accelerating.

My totally stops accelerating and the it back fires so its got to be fuel cut.

 

[Defiant]

My totally stops accelerating and the it back fires so its got to be fuel cut.

It doesn't sound like fuel cut. Fuel cut is like when the dog chasing Foghorn Leghorn gets to the end of his rope at a full run.

 

[Liger]

Well, i had a similar problem with my car. At the time i was not too smart about knock and fuel trims and whatnot. So after installing my EvoIII b16g (which was not controlled, just ran full boost at 18 or so psi). When i would go WOT and hit 18 psi my car would like cutout very quick and repeatedly and not really accelerate anymore. I had a walrbo 255 and 550cc injectors as well. Apparently what was happening was that one injector was actually putting too much fuel into the cylinder and i guess firing every other power stroke or something similar. But i would turn the boost down and wouldn't have this problem. I was monitoring through dsmlink for those wondering.

Now i run my stock injectors at 55psi of fuel pressure and have no knock at all and good a/f ratios on 17-18 daily boost. I dont know if this helps but pull your plugs, see if some are running too rich or are fouled. You can also check ur o2 voltage, if it's very sporadic and changes very suddenly, not smooth from rich to lean like normal. Keep in mind this is during normal driving, at WOT it will be at rich....Brandon [VFRacing]

 

[Liger]

Update, today, i put in my 550s again after getting them back from PTE(supposidly fixed) and tried them out. They are worse now and car sounds like it is on cams. But i adjusted the fuel trims and settings to make it run decently, boosted to 18 psi and on a slight uphill the car did that jolting again, where it would basically backfire, but not as hard as a normal backfire if you will. So i pulled the plugs and sure enough the bad injector is still dumping too much fuel into the cylinder and fouls the plug so when it's at wot it prevents it from sparking, thus extra fuel in the exhaust stroke and then ignites, backfire. So back in the old injectors go at 55 fp. Good luck Brandon [VFRacing]


(sry if my last post was kinda dissorganized, it was late at night )

 

[95undrpsi]

I haven't got to work on the last couple days because I've been doing crap. I think that I'll put on the exhaust and check for boost leaks before I drive it. But do you think I'm going to need a fuel pump with running a blow thru set up.

 

[Liger]

Well, i'd definitely check for boost leaks since u haven't done that yet. I dont use the MAF-T so i couldn't tell you if u would need a fuel pump, but i wouldn't think so....Brandon [VFRacing]

 

[Burnett03]

Now i run my stock injectors at 55psi of fuel pressure [VFRacing]

wow, ya that was a great, awesome idea!

 

[Liger]

What's wrong with doing that? it's putting in around 11% more fuel and the 550s were putting in 18% more fuel. And i have dsmlink to compensate for the added fuel. So please tell me what is wrong with doing this? Brandon [VFRacing]

 

[1993eclipseGS]

On my way home from the track I hit fuel cut for the first time in my life. Both my girlfriend and I, Almost flew through the windshield literally. Thank god the seatbelts lock up. I hit I believe 22psi and I finally hit fuel cut, That's on stock injectors. Granted I was on 118octane gas. It's scary, You'll know if you hit fuel cut. Go run into a wall at full speed,That'll give you an idea what it feels like...

 

[obee1595]

I just got my 6bolt swap running good yesterday. I took it for a drive to see if everything is working right. I gave it gas and it hit fuel cut every time it hit max boost(15 psi). I was running no exhaust at the time and my mod list is in my profile.

You should try getting a MAF translator that fix my fuel cut.

obee

 

[95undrpsi]

You should try getting a MAF translator that fix my fuel cut.

obee

UMM... I already have one.

 

[Liger]

Correct me if i'm wrong, but i dont think the MAF-T can defend against fuel cut. I think your best bet is to just do some fuel upgrades. If you are desperate you "could" but not recommended, hack the orginial maf and take out the lower honey combs, and not use the MAF-T but you might need it for other tuning with your setup....Looks like it's time to updrage ur fuel Brandon [VFRacing]

 

[95undrpsi]

Last night fixed all of my boost leaks and put my exhaust on still hitting fuel cut . I think its time for a fuel pump.

 

[99GSX Swede]

I had the same problems in my 99 GSX. I would hit fuel cut at 14.5 lbs everytime at 4500 rpm. Once I tuned with the MAFT I was able to get to 16 lbs on stock injectors before timing started to get pulled. So, yes get a pump and bigger injectors and make sure you are logging to see what is going on.

PS
Yes you can get rid of fuel cut with a MAF and translator the same way you would with a SAFC.

 

[95undrpsi]

Once I tuned with the MAFT I was able to get to 16 lbs on stock injectors before timing started to get pulled. So, yes get a pump and bigger injectors and make sure you are logging to see what is going on.

Do you remeber what the setting of your Maft to give me a bse start. I'm a Rookie toa MAFT.

 

[oldman]

A lot of mis-information about fuel cut here.

1. No, MAFT will not fix fuel cut.

2. Fuel cut has very little or nothing to do with your fuel system so bigger injectors or pump will not fix fuel cut either.

Fuel cut occurs when the maximum air count allowed which is pre-program into the ECU is reached, ecu then stops the injectors from firing to protect the engine. The most common cause of fuel cut are boost leaks, boost creep (or out of control boost) and defective mas/maf. The only way to remove fuel cut is through re-programing the ECU via eprom.

 

[SethA]

Won't compensating for larger injectors or higher fuel pressure with a piggy back raise the fuel cut threshold? The piggyback fools the ecu into thinking less air is coming into the engine right? I agree that more fuel will not eliminate fuel cut, but compensating for more fuel will allow more boost before cut. Please correct me if I am wrong.

Seth

 

[oldman]

Won't compensating for larger injectors or higher fuel pressure with a piggy back raise the fuel cut threshold? The piggyback fools the ecu into thinking less air is coming into the engine right? I agree that more fuel will not eliminate fuel cut, but compensating for more fuel will allow more boost before cut. Please correct me if I am wrong.

Seth

Yes, piggy back fuel controller can help delay fuel cut by tricking the ecu but it will not eliminate it, kinda like hacking the maf. Most of the time, hitting fuel cut is an indication that something is wrong with the system, in most cases boost leak, so you're basically bandaging the problem instead of fixing it.

 

[95undrpsi]

I checked for boost leaks I have little or no boost leaks. I should have mentioned this a lot earlier but I do have a check engine light for a 02 sensor will that make a difference?So what your saying is that I bought a fuel pump that I don't need. Could I have hooked up a vacuum hose wrong or something while doing the swap.