Ok, so ever since my rebuild, my car has been doing some odd things. For instance, on certain days, if I rev around 5k or so and let the rpms drop, my car will die. And on top of that, I've tried the lubricants and had them reajusted, but my belts will not stop squeeling. And it's gotten worse, like to the point they sound like theyre about to snap. I also need to know how to cure fuel cut, cuz I think that's what I'm hitting now. My mods are:

-FPT28 Turbo
-3'' Apexi Downpipe
-3'' Tsudo Catback
-NGK plugs (gapped @ .30)
-K&N Airfilter
-HKS SSQV BOV

I think thats it. Thanks guys.

Don't forget all your stickers! ;)

Rewire your fuel pump--that should help with fuel cut. As for the rest of it, I dunno...

Dane

Does your car die when it's warm out? Or just in the cold? I know my car will sometimes die when it's this dang cold and I haven't let it warm up long enough.

Also, is that all you have for mods? You shouldn't be hitting fuel cut with just that I wouldn't think. I'm no expert though... If you are, rewire your fuel pump and see if that helps. If it doesn't, I've got a new Walboro 255 lp fuel pump sitting at home I believe... :)

Is your BOV recirculated into the intake or is it venting to the atmoshpere? if you are venting to the atmoshpere that could cause your car to die. I would suggest putting a larger pump in your car.

-J

Yea I doubt you have a maft so Id say that the venting is causing the dieing.

Also you should upgrade to 550s, I have stock ones now and even at 13 psi in this cold I get fuel cut and my duty cycle hits 100+.

I just put in some 550s and should have the car up tommrow and well see if thats what the culprit was for fuel cut. IC pipes and the GM maft really open up the airflow

He has a 2g Peter, that is a whole different deal. I am willing to bet it is dying because of the vented BOV too. I would at least rewire the fuel pump. You are in pretty desperate need of a SAFC or DSMlink too.

To be honest, the BOV sounds like the problem. Because I only experienced the fuel cut thingy once I put that in. It is venting to the atmoshpere. But at the time I had my boost restrictor pulled out. Now it's back in, and I have to put in the MBC I bought. As far as it dying out, it mainly happens when it's cold out.

I'll get you a 1G BOV and you can give me the SSQV for my van.

Eat a dick Dane! jk LoL. I love this thing. :bounce:

Yeah, if you are venting to the atmosphere, that could be causing your car to die when it's cold out. Venting to the atmosphere isn't recommended under any circumstance and usually makes your car run like crap.

so to sum it all up.....

get a bigger fuel pump
do not vent your bov

I am sue it is the bov that is stalling the car. The same thing happens with mine sometimes. You are not calling fuel cut the jerk when you put you foot on the clutch of let off the gas are you? That would also be because of the bov. It is not fuel cut however. What boost are you running? I see no way for you to be hitting fuel cut on your setup unless you are running mad boost.

As far as your next mods go, get a fuel pump, 550's, and a SAFC along with a datalogger or dsmlink.

What do 2gs differ with fuel cut? I guess I didnt know the diff besides the 2gmaf being different.

Some cars fuel cut before others... I dont think I should be fuel cutting at 13 psi when its cold out. right?

I did wanna get a fuel pump. I just pm'd Jana about it. And I do want a SAFC...but I dont have the money to burn on one of them right now. Not unless I can find one for cheap.

nah u don't need an safc unless you upgrade to bigger injectors. A bigger fuel pump should cure your fuel cut all by itself.

But I heard that you couldnt just cure fuel cut. I heard it was in your ecu?

Fuel cut is basically the ecu telling you that there is too much air coming in for the fuel to support it. This is why you get an safc, to lean it out and fool the ecu into saying there is less fuel needed for the air coming in (metered air).

If you get 550s the D/C rises therefore the fuel cut limit rises too. If you get a bigger fuel pump that raises pressure which make the Injectors work less i think.

Correct me if Im wrong.

I am not sure about a fuel pump having much to do with fuel cut. Larger injectors dont even help if you are unable to lean them out. Larger injectors help you because you can "fool" the ecu by leaning out the mas reading. What boost are you running? Don't guess either. You may have boost creep bringing you to 20psi and hitting fuel cut. John had that a while ago on his 1g. For him, boost creep seemed to come and go with winter.

ok, i guess "cure" was a poor choice of a word to use. Fuel cut is not a disease or anything, its there to prevent you from running too lean and messing up internals. In your mod list you have a few things that add more AIR, but nothing that adds more fuel. So you've maxed out your fuel pump and it can not pump in enought fuel to mix with all the air you're shoving in there. So a fuel pump that flows more will make it so you aren't hitting fuel cut anymore. If you really really wanna just get rid of fuel cut all together, you can buy a gm maft and it allows u to shut off fuel cut permanently, but then that'll just allow you to run as lean as you want, and fuel cut just won't hit. So you'll just run as hot as u want, but u could start doing serious damage to the internals. And if you're not monitoring egt temps, then you'd have no clue that you are running too hot and just start ruining stuff. God im tired, sorry if this isn't worded to great.

Larger injectors dont allow you to lean out more.... it allows you to run more boost without maxing out your injectors.

I have the MAFT and the stupid switch that supposedly shuts off fuel cut doenst do shit.

Venting isn't good for his setup, but common on more in depth applications.

with a stock MAS setup, venting will cause problems. If you are using a VPC or a gm maf setup, then you will be able to vent just fine.

i got the word "cure" from a DSM faq.

im sticking with my original responce

for your setup...
bigger fuel pump = no more fuel cut

bigger injectors and some form of fuel control would be a good idea since you are using a larger turbo now, but not 100% necessary if you don't run high psi.
and now im off to bed

Fuel cut has nothing to do with fuel flow.

You could put in a 1000lph fuel pump and rewire it and it's won't affect fuel cut at all. Putting in bigger injectors or raising the fuel pressure with also not fix fuel cut on their own.

Fuel cut is based purely on the ECU reading to much air flow, it doesn't give a crap about fuel, it has no way to even know if it's running lean at WOT. The ECU is basically just programmed that if it sees over X amount of airflow at X RPM it does fuel cut because it thinks the wastegate has failed. You have to make the ECU see less airflow to keep it from fuel cutting. You can do that by lowering the boost, hacking the MAS, or using an electronic fuel controller to lower the airflow signal Hz getting to the ECU.

See I thought it was all ECU.

I know I know!!!!!! SELL IT!!!! :stick:

:blink: H8tR! :razz2:

Finally some correct info! I don't buy into the gm maft stuff much just because of Peter's eperiences. Having to turn boost down to 13 psi (with the gm maft) so I don't hit fuel cut is pointless IMO.

Get 550's and a SAFC to help with fuel cut. If you don't have much money you can hack the mas a bit. You will need a fuel pump in your setup but it will NOT do shit for fuel cut.

If you get larger injectors, you can remove some of the reading from the MAS with teh SAFC. That is how you get away from fuel cut. I am not sure of the exact number on a 2g mas but you would hit fuel cut if you exceeded the mas' rating of 2100 (guessed on #). If your car is overrunning the mas (say getting 2200) you will get fuel cut. That is why a pump will not help you. You need to take away part of the airflow reading with a SAFC or by hacking the mas.

Kid what are you talking about, "buying into the gmaft and 13 psi?" Whats pointless about turning it down so I dont get fuel cut???

Only when its 40 degrees or below CURRENTLY with my 450s and pump gas I cannot go past 12-13 psi becuase I will overrun the injectors. Therefore I will fuel cut.

I have been stating that airflow is what causes the ecu to fuel cut... Not always will the bigger injectors or a bigger pump CURE it. It will help it though, or raise the psi it will cut at.

I run richer with pump gas, I have a safc and I dont like to lean it out too much becuase of knock... Summertime is all candy when it comes to fuel cut cuz its warm out and the air is less dense.

No, it won't help at all, unless you remove airflow signal with a fuel controller. Putting in a bigger fuel pump will not change where it fuel cuts at. The reason why you fuel cut when its colder out is because 14psi when its 75 degrees out is not the same as 14psi when its 30 degrees out. Colder air is denser so when its cold out the ECU sees more airflow at the same boost level than it does when its hot out. Which causes its fuel cut routines to kick in earlier because they are based off airflow not boost psi or running lean.

As far as the MAFT, it uses the same tricks that an AFC does. It is no better nor worse than using an AFC to get around fuel cut, so you need to use larger injectors in conjunction with it for it help fuel cut at all.

How exactly do you hack the MAS?

definetely not thru ssh

I dont know, differnt threads say differnt things, FAQ says differnt things and when I have posted in the past about fuel cut why did you guys tell me to get 550s? Oh well.

So does the Mas read fuel DC based on airflow or is it real dead time for the injectors? If DC has nothing to do with fuel cut then why when you get up past 100 or so it will fuel cut?

Im confused.

Well, even if it is tied to pulse width (duty cycle is just a logger calculated value from pulse width, rpm, and dead time), pulse width is directly tied to airflow. If you put in a bigger fuel pump, you ECU won't change its duty cycle/pulse width to compensate for more fuel because if has no way of knowing that there is more fueling available.

Here is some info on the fuel cut routine in the ECU's code from a post by Keydiver.

honeycombs. No not the cereal.

People don't hack the 2G MAS very often. They can handle 3000hz and 450whp stock. You have to start hacking the 1G MAS pretty early on if you want to continue to use it and make any power. It likes to start overrunning when you get close to 2000hz. On a 1G MAS, the first steps are to remove the lower honeycomb and back out the calibration screw. If that isn't enough then you can start removing some of the lower half of the MAS with a dremel. People often at that point also solder a resistor or potientiometer into the intake air temp sensor line to fool the ECU into thinking it's colder outside and adding more fuel to compensate for the added airflow that it won't be reporting to the ECU. You don't want to hack the MAS more than you currently need because you can run into timing/knock problems and it gets hard to tune the more it is hacked. You also never want to remove the main honeycomb, without the main honeycomb it won't meter the air worth a crap.

Personally, im not so sure if it's fuel cut anymore. I think it has to do with my BOV venting to the atmosphere.

Fuel cut feels like the car basicall hits a wall for a second. Your face should almost eat the steering wheel.

I know! Downpayment for a house! :P