Finally hit fuel cut, but why not until now?

[yup talon]

First off, Im still on a completely stock fuel system. Secondly, a month ago i installed a ported 14b and left it at 15psi since then. i use 93 octane fuel always.

A few days ago i went to the track for my first time. Ran the first few runs at 15psi. Not wanting to go home dissapointed i decided to mess with my MBC. Without testing it prior, i found out on the strip that i turned it up to 22-23psi. Had no problems whatsoever. I could tell it was running pretty lean, but i never hit fuel cut. I turned it back to 15psi when i left that day. The next day, i was running to the store, and decided to see what that 22psi felt like on the street (later finding i only turned it up to 20psi.) I didnt get ½ mile down the road before i learned first hand what fuel cut felt like. At the store, i turned it down to about 18psi, and got fuel cut on the way home too! Since i still hadnt filled my tank since before the track, i thought maybe it was cause i was like almost out of gas. I filled the tank last night, and this morning hit fuel cut AGAIN.

Why would i have no problems at the track at 22psi, yet have problems on the street with <22psi?

The only other variable i thought could have been valid was that the day at the track temps were above 90*. The last two days have been high 70's. anybody got any ideas?

Also, I have a datalogger on its way to me right now so im hoping t hat will help diagnose the problem. I also plan on ordering a walbro 190 and re-wire within the next week. Should this solve it? or at least help?

 

[sweet97]

Fuel cut has nothing to do with lack of fuel. It is caused when the ECU see too much air. Cooler air is denser and that is most likely your problem/answer. Just back off the boost on cooler days/nights until you get fuelcontrol like a MAF-T or safc.Mark

 

[zachakagoat]

You're gonna blow your new 14b with that kinda abuse

 

[Precision]

You're gonna blow your new 14b with that kinda abuse

If you want to run that much boost on a 14b I recomend Cryo treating

 

[CanadianTSi]

The only other variable i thought could have been valid was that the day at the track temps were above 90*. The last two days have been high 70's. anybody got any ideas?

Thats the Exact reason...

So how much faster did you run with 20psi versus 15?

 

[foreverinvayne]

was the car cold when you ran it on the street like that? Because my car only hits fuel cut right after i start it up before it's been in closed loop and warmed up for a few minutes.

 

[yup talon]

Thats the Exact reason...

So how much faster did you run with 20psi versus 15?

Not very much faster i still ended up leaving kind of dissapointed. Then again it was my first time at the track ever. ET only improved .2

was the car cold when you ran it on the street like that? Because my car only hits fuel cut right after i start it up before it's been in closed loop and warmed up for a few minutes.

Yes, it was happening after the car has been sitting. It reached temp, but it hadnt been at temp for long. could this be a factor? it still just boggles my mind that i could push 22psi no sweat for about 8 passes or so, yet cant boost 18psi on the street without hitting cut. I'll see if i still have problems with that after driving around for a while.

 

[yup talon]

If you want to run that much boost on a 14b I recomend Cryo treating

and by this do you mean use an intercooler sprayer? I have been thinking of rigging one up. I'm still on the stock sidemount.

 

[Burnett03]

22psi on a stock fuel system is dumb
and 22psi on a 14b is pretty worthless

 

[91gvr4]

22psi on a stock fuel system is dumb
and 22psi on a 14b is pretty worthless

Agree on number 1. Disagree on number two. Everyone always decides to upgrade way to early. 14b with all supporting mods hauls ass. Now if you getting any higher then 22psi its worthless.

 

[CanadianTSi]

Not very much faster i still ended up leaving kind of dissapointed. Then again it was my first time at the track ever. ET only improved .2

You don't have the supporting mods to run this much boost, leave it at 15 and you car will be happy.

 

[yup talon]

I wasnt asking if you thought me running 22psi was a good idea or not. The car felt much faster there than when it was at 15psi, so calling it "dumb" and "worthless" makes me wonder what you meant by that. And its not like im pushing 20+psi daily, ive never had it that high except for at the track that day, and now its back down to 15.

canadianTSi - what other sort of supporting mods do i need to push high boost? just a pump/afc?

 

[JiveMasterT]

I wasnt asking if you thought me running 22psi was a good idea or not. The car felt much faster there than when it was at 15psi, so calling it "dumb" and "worthless" makes me wonder what you meant by that. And its not like im pushing 20+psi daily, ive never had it that high except for at the track that day, and now its back down to 15.

canadianTSi - what other sort of supporting mods do i need to push high boost? just a pump/afc?

ah, the question about supporting mods... Can be answered here
don't feel like reading? well, here's the cliff's notes:
pump
injectors
fuel pump
maybe a bigger turbo if you wanna be running 22psi... 22 psi is out of the efficiency range of that turbo and you're running it hard hair dryer style, especially if you have the stock smic.

leave it at 15psi and dont bring it up again unless you like fuel cut and engine destruction...

 

[yup talon]

Ive read the tech guide here time and time again, notice that aside from a fuel pump, i have exactly everything in "stage 1".

And like i've said before, im at 15psi right now, i dont plan on running 20+psi daily. I jsut wanted to know how i got away with it at the track.

 

[JiveMasterT]

Ive read the tech guide here time and time again, notice that aside from a fuel pump, i have exactly everything in "stage 1".

And like i've said before, im at 15psi right now, i dont plan on running 20+psi daily. I jsut wanted to know how i got away with it at the track.

The reason you got away with it at the track was because the air temperature was 90 degrees, which means it isnt as dense. I believe there is a setting on the 2g maf to make it so it doesnt see as much as as there actually is... but ive never played with it on mine.

 

[onegee]

and by this do you mean use an intercooler sprayer? I have been thinking of rigging one up. I'm still on the stock sidemount.

No, he meant cryo treating. I believe www.ffwdconnection.com does quite a bit of cryotreating to their parts.

 

[Steve Hebert]

The reason you got away with it at the track was because the air temperature was 90 degrees, which means it isnt as dense. I believe there is a setting on the 2g maf to make it so it doesnt see as much as as there actually is... but ive never played with it on mine.

My thoughts exactly - The only time I've ever gotten fuel cut was on a cold day. (I normally don't take the car out in the winter)

I'd guess if you took it on the street on a 90 degree day you may not see fuel cut.

 

[psychlow]

By upping your boost for the first time, chances are you created a boost leak. The increased pressure created a leak that didn't appear until after your track runs.

Check for leaks. Once you find them and correct them, your fuel cut woes should go away.

Next, running that much boost without the proper supporting mods is asking to trash your engine. Yes, it will be faster - your car is always fastest right before it grenades - ask any tuner who's found out firsthand.

 

[94Jettameowpsst]

Runnin 22psi on a 14b isnt pointless if you have the other supporting mods. I ran 22 psi at the track when i had the stock 450s, a walbro 255 and a fmic. If my piping wouldda stayed together after the 8th mile 1k foot mark, i probably wouldda been in the low 13s high 12's considering my 60ft was mid 1.7 sec and my trap was 98mph..keeping in mind that i didnt touch the gas after the 8th/1kfoot mark.

 

[Project Draven]

not to get off topic but i would like to know what a stock gsx runs boost wise. some ppl say 14 some r sayin 10 and one other told me 8 or less
the reson i am asking is because i have a 95 gsx and 2 nite i ran a g force unit on it and i got the following results

0 to 60 6.3 secs
1/4 mile was 14.9 at 95.4 mph

someone plz help me out here thanx in advance

brandon
by the way 94jettapsst do you go to any meets by any chance because i am in mt. pleasant pennsylvania i am about less than 20 mins from u and me and a bunch of others roll up to the mount pleasant walmart and sometime the big parking lot at warehouse groceries down on 119 if u kno what i'm talking about. and we sometimes go to the parking lot up at your walmart check it out sometime
peace

 

[Tort9320g]

22 psi with a 14b on a 90+ degree day with no supporting mods. You're just blowing hot air at this point. Be careful or you might be tearing this bad boy down sooner than you planned. I wasted my head gasket pulling a stunt like this.

Dave

 

[yup talon]

UPDATE: its at 15-16psi, solid. we've had some hot/cool days and havent had any problems.

Only thing that happened that was out of the ordinary was last night, i was on the highway doing about 55-60 and wanted to pass this guy so i throw it down into 3rd and hammer it. at about 5.5k something happened very similar to fuel cut. The symptoms were as follows... loss of power, shifter was still up in 3rd, but gasing it did nothing just revved. a flash of light reflected off the car next to me, and a puff of smoke came out (i could see it thru the headlights of the cars behind me) The car still drove jsut fine after i moved the shifter into 5th. After getting into town i find all the other gears work fine too. ...any ideas anyone?