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

[~laser_craver~]

ok i got the compressor and it is on the tmming belt side of the intake manni and seems to be under the manifold.... but there is no lines running under there anymore for i have no more emmisions.... and it almost looks like the intake manni gasket, ima get my dad to pump air into it while i feel around the gasket. like i said it leaks out tremendously fast

[~laser_craver~]

ok i got it all figured out bro. it is the intake manni gasket. it was blown there was a peice of it hanging out like a peice like 1 1/2'' long so ima order me a new one as well as a inner throttle body gasket because the one sbr sent was way way way wrong it was leaking aswell. tahnkx for all your helpy dude you rule!

[oldman]

Originally Posted by ~laser_craver~

ok i got it all figured out bro. it is the intake manni gasket. it was blown there was a peice of it hanging out like a peice like 1 1/2'' long so ima order me a new one as well as a inner throttle body gasket because the one sbr sent was way way way wrong it was leaking aswell. tahnkx for all your helpy dude you rule!

Not so fast, spray soapy water on the injector seals, both sides of the TB shat, BISS screw and re-test, you don't want to take things off twice do you?

[~laser_craver~]

the throttle body gaskets are brand new aswell as the injector seals they have maybe 20-30 miles on em

[oldman]

Originally Posted by ~laser_craver~

the throttle body gaskets are brand new aswell as the injector seals they have maybe 20-30 miles on em

So you did end up taking things off twice.

[~laser_craver~]

ive taken the injectors fuel rail and throttle body off maybe 3 times in this last week! and now i get to take the entire intake manni off yay! NOT

[oldman]

Originally Posted by ~laser_craver~

ive taken the injectors fuel rail and throttle body off maybe 3 times in this last week! and now i get to take the entire intake manni off yay! NOT

It's much easier to get to the bottom manifold bolts if you remove the DP and manifold bracket and go from bottom up, especially if you still have the AC compressor.

[GSTdude06]

The more times you take off stuff that has a gasket under the worse the gasket can leak. Its compresses to form a seal and everytime you compress it more and more is doesnt seal correctly. I learned that the hard way by breaking off a head bolt on my engine cause my gasketed was compressed and I kept tighting the bolt. Still leaked to......sucked really bad

[fwdeclipse]

Well my problem is that when the car hits about 4k it cuts hard ,then it will continue and cut again every 500 rpms . I cant seem to figure this out.I have no boost leaks, held 20psi for 30seconds.It seems like it started having these problems after I changed by tb shaft seals.Also i have a joe p mbc and it is running 18 psi of boost set all the way down.If i take the bc off it will run 11psi,it doesnt cut out but it sputters at high rpms.Before i put in the 190lph fuel pump in,the boost controller set all the way down ran about 14psi. Please help!

[weith1111]

Check you plugs. If you are sure it's not air or fuel, spark is the only culprit left.

[fwdeclipse]

I just put brand new plugs in it a week ago and that did not help.I gapped them at .30 is this wrong.Also im not sure if its not fuel related,pretty sure its not air related though.

[andytalon]

Fuel cut is caused by the ecu seening a large airflow value from the maf which works out to roughly 100% dudy cycle on stock injectors. If ya install 550cc injectors which are 18% bigger than stock injectors, then adj the afc to compensate for the larger injectors, you wont hit fuel cut untill you make up for tha 18% airflow buffer. idealy you should get the injectors, afc, and other ecu mods needed to run ridiculous boost levels without running too low on fuel or hitting fuel cut, hope that helps a lil.

-andy

[weith1111]

Plugs should be .028 but that should be the problem in that case. You sure you got the correct plugs? NGK BPR6ES?

Turn the boost down to 16.

You should be able to prevent fuel cut with your current setup. Do another boost leak test and push on all the pipes and stuff. It may not be leaking sitting still, but with the motor moving all over something may be letting air out.

[fwdeclipse]

I checked for boost leaks again and there is a tiny one at the top of the bov,not sure if its enough to cut out so bad. Also i have my mbc turned all the way down and it wont run anything under 18psi. If i take it off it runs 11psi,and still sputters a bit. I will regap my plugs and probably put new wires on and try that.

[weith1111]

If your MBC doesn't go under 18 you have a problem. Is it hooked up properly? Setting it as low as it goes should give you stock boost.

[fwdeclipse]

Yeah i figured that was an issue.Before i put the fuel pump in it was going to 15psi set all the way down .Do you think it could be a bad mbc.I know for a fact its hooked up correct. I have one end to the wastegate and the other end is teed to the bov.

[dub2gsx]

Make sure your boost controller is hooked up right. Then check and see if your plugs are arking in the dark with a squirt bottle. Make sure your plugs are gapped to spec. .028-.032. When is the last time you changed your fuel filter? Did you rewire your fuel pump and if you did, do you have a good connection!! You shouldn't be running max on duty cycle on your 450's quite yet! If it is still hitting cut then ????

[awdthomas]

check the spring in the boost controler.

[fwdeclipse]

No i have not rewired the pump yet. I just got some new wires and im gonna put them on. Also i am not sure if it is actually fuel cut,but it feels kinda like that. I tried to change my fuel filter last night and it was a bitch. I could not get it off,but iam going to try again tomorrow night. I have another boost controller and im gonna see if it does the same thing. I have the plugs gapped at .30 and im gonna try .28.

[fwdeclipse]

How do you check for arking?

[ddavisaf]

What kind of spark plugs do you have?
Are you venting to the atmosphere (BOV)?