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fuel cut problem

2904 Views 12 Replies 6 Participants Last post by  tstkl
ok so i have my boost set to 15 lbs i went to go turn it up to 19 tonight and it spiked up to maybe 22 and i hit fuel cut like 3 times

the last time it did it i threw a overboost code

if i turn it up any higher than that the bov starts to flutter rapidly then i hit fuel cut

the mods i have are
hallman mbc
aps bov
injen intake/upper ic pipe

someone was saying if i get an exhaust which im planning on for my next mod anyway
it should fix the problem


can anyone give me some help with this?:(
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:confused:
Hmmm...
I've never used an APS valve, but a decent aftermarket valve shouldn't have problems with 19-22psi, nor is fuel cut common at those levels.
Have you checked the line to your boost gauge for kinks or leaks?
An untuned intake, then a BOV that partially vents to atmosphere is a sure recipe for problems. I would start by putting the BOV back to stock, then see if it happens still. If so, put the intake back to stock and try again. If it goes away in either of these scenarios, you know the problem. If it persists with the stock intake and stock BOV, let us know, and we'll go from there.

PS. Why are you running 15psi? Snow reasons or something?
yea i spent half the day yesterday with my car on the lift putting everything back to stock


same problem still

im running 15 psi because if i turn it up any more than that it spikes then i hit fuel cut


i put everything back in and i still had the problem so now im just lost:cry:
dr0wningless0n5 said:
yea i spent half the day yesterday with my car on the lift putting everything back to stock


same problem still

im running 15 psi because if i turn it up any more than that it spikes then i hit fuel cut


i put everything back in and i still had the problem so now im just lost:cry:
At this point put the boost control system back to stock (all lines correctly connected, with all restrictor pills etc) and take it to the dealership. This is what they are there for, to fix problems that are not caused by the owner or by modifications he has done. If your modifications didn't cause the problem this is the time to get the dealership involved to solve the problem.

Keith
dr0wningless0n5 said:
yea i spent half the day yesterday with my car on the lift putting everything back to stock


same problem still

im running 15 psi because if i turn it up any more than that it spikes then i hit fuel cut


i put everything back in and i still had the problem so now im just lost:cry:
Aha, if you are hitting fuel cut at anything over 15psi, then there is a definite problem elsewhere. You shouldn't hit fuel cut unless you're up closer to 24-25psi or so. You can't get enough airflow below 20psi to cause fuel cut, so that's weird. I suggest doing what Keith said and re-installing the factory boost lines...not just any vaccuum lines...the EXACT FACTORY BOOST lines with the 2 restrictor pills.

Let us know...
ok so i put those lines back in like you guys said and same problem i think my boost gauge is off by like 10 lbs

when i shut the car off it should go back to 0 on the gauge i would think but it just goes to -10

i unplugged the line and it still stayed at -10


now i have to figure out how to fix that
Holy crap. -10 when turned off? Yeah, it should rest at 0.
I had that happen with a brand new gauge i had bought for my DSM and I was pissed, I returned it and got a new one that worked perfect. You were just running more boost then you thought that seems like the problem. good luck fixing it, let us know what works.
yea ill probably end up buying a new gauge ummm where do you guys have yours tee'd into? i have mine on the line going to my bov i used to have it on another line but that changed when i put my mbc in
im pretty sure thats where i had it before but i had to disconnect that because of my mbc
has no one suggested a boost leak test? I know Im just a little dsm'er talking here, but normally when we experience fuel cut it is due to the fact that there is a leak in the lower or upper intercooler pipe, the intercooler itself, the intake manifold (yours truely...lol), the throttle body, or the bov. any leaks anywhere after the turbocharger at high boost levels become HUGE problems and lead to fuel cut. what you need to do is pressurize the system, look for leaks, and then spray where you think the leak is with soapy water and see if it bubbles. if it does, theres a whole in the line. really common leaks for us are the throttle body shaft seals, but thats probably due to age. how you pressurize the system is you take off the intake pipe, use a silcon coupler to attach a pvc cap of the right size to the end, and install a bike valve in the pvc cap (before you clamp it down that is), then use compressed air in the system to look for a leak. pressurize it to 20+ psi (don't overdo it or you'll just blow off the pipes) and look+listen. We normally do 20psi for 30 seconds mininum, but with cars that are from the factory at 20 psi, I dunno how high you guys should go. Obviously if it can hold 60 psi forever your in great shape, but dont try 60 psi and expect everything to be fine. try like 25 psi or 30 MAX.

remeber, this is just a dsm'er who has watched the top gear where they test the evo VIII vs. a lambo like 5000 times. Those power slides were enough to sell me on the fact that my next car will be, without a doubt, an evo 8, 9, or hopefully (active braking here I come) an evo X. now I just need that green stuff, I think its called money? I dunno, test driving these things at my local dealer will have to suffice until I have the money for an X.
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