Ok here is the story. My car had a i/2nd cat hollowed out/mbc set to 18psi for over a month and it ran fine for the month or so it was on with zero problems ever. Yesterda I installed a TBE and turned the boost down to stock levels of 14-15 psi. Today was 45-50 degrees out at night and in anything after the first two gears the car is cutting out. Keep in mind i have the atp boost cut defender and the boost guage never reads over 14-15 psi, so it has to be fuel cut. Is it possible that some how with my two power mods i am running out of fuel!? This is retarded and i dont understand how i dont run out of fuel at 18psi, but i run out of fuel at 14 psi with a TBE. Any answers? Am i having some other kind of problem?
How am i hitting fuel cut?
- Thread starter laloosh
- Start date
- :
- 2002 BJFW, 2007 BK3P, 1979 SA22C, 2005 BK3P
we ran this exhaust on truboost's car in the dead of chicago winter and did not hit fuel cut with it on stock boost. he had an intake as well. the turbo could be spiking real high, real fast and then settling down, but the BCD should resolve all this.
it could be a faulty BCD. the one on our ms6 broke and the car was doing the same thing all of a sudden.
it could be a faulty BCD. the one on our ms6 broke and the car was doing the same thing all of a sudden.
the thing is that im not spiking, nor am i hitting a high psi. It does it lil spike to 16-17 pulls past it to hold 14-15 and then around 4500rpm is started to stutter a little and then it sounded like bomb went off. I think i might have shot fire out of my exhaust. Now i know there is noway in hell that im running to rich right now.....right? So i gotta be leaning out and hitting fuel cut. if thats the story i hope this new fuel pump solves my issue.
Look at my dyno with just intake and Vibrant DPback. Im running WAY richer after installing my exhaust. Just nuts.
View attachment dyno MS3.pdf Red is with the exhaust.
I wouldnt assume anything with this ECU. Check out my thread in the MS3 Engine section. Your input would be appreciated.
AutoXRacer
Member
Why did you guys change the exhaust? Was it only for sound?
I've been reading that the stock exhaust is pretty good and not very restrictive...but it is a little quiet for some folks...
I've been reading that the stock exhaust is pretty good and not very restrictive...but it is a little quiet for some folks...
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SharkDiver
Member
- :
- Speed3
My car is doing the same thing.I have the boost set to about 17psi but when I get to about 4k rpm my boost drops to 14-15 and studders,The boost will bounce between 14-15.I got the bad spiking under control but now I have this problem.I will even do it with the boost turned all the way down.When I remove my mbc and put it back to stock and leave the fcd on it stops doing it.Ive been tring to figure this problem out also,I think it may be fuel cut.Is there a way to test the fcd?Can I use a compressor or somthing?
i dunno if i mentioned it in this thread becuase i posted this in a couple places, but i removed my mbc/fcd and the car is still doing it if not got worse. its nothing to do with the amount of boost the car is running cause it never ran a high amount after the tbe install. its got something to do with the pos fuel pump and providing enough fuel at cold temps
AutoXRacer
Member
Thats what I meant... I was looking to upgrade the downpipe, but I was told that the stock exhaust system on the MS3 is pretty good as is. The pressure drop through the cat is gained back through the rest of the exhaust...
Just trying to understand the reason for changing out the exhaust system specifically on this car. Supposedly there are no significant gains by replacing it other than sound... Seems like this car doesn't like to many mods...
Thanks...
a tbe exhaust gains up to 30 whp through out the band and sees peak gains of about 20.
AutoXRacer
Member
Really? That much...? Wow...
I was talking with BEGi and they swear there is not much to gain from an exhaust... Hmm...(uhm)
I was talking with BEGi and they swear there is not much to gain from an exhaust... Hmm...(uhm)
from a catback. not from a full tbe
well here is an update. on the way to the gas station, its 52 degrees out, the car did its usuall stutter. i got gas, the stutter has yet to come back. im gonna be pissed if i spent all this time playing with differnt set ups only for it to be a bad tank of gas.
What i tried.
1. i was running a lil knn crank breather along with the capped hole on the intake. i put it back to stock nothing seemed to change.
2. i tried playing with the bpv springs and went to the yellow spring instead of the blue thinking that maybe its too hard...nothing changed
3. i checked every single hose for a vacum leak...nothing
4. i looked undercar for visiable exhaust leaks, no soot to be found anywhere.
5. i got gas and it has yet to happen.
What i tried.
1. i was running a lil knn crank breather along with the capped hole on the intake. i put it back to stock nothing seemed to change.
2. i tried playing with the bpv springs and went to the yellow spring instead of the blue thinking that maybe its too hard...nothing changed
3. i checked every single hose for a vacum leak...nothing
4. i looked undercar for visiable exhaust leaks, no soot to be found anywhere.
5. i got gas and it has yet to happen.
SharkDiver
Member
- :
- Speed3
Is yours doing it at about 4k rpms?Thats when mine starts to do it.Is this doing any damage to the motor you guys think?
