so today when i was driving on the highway in fifth gear, i gave the car a little gas, and after it fully boosted for about 2 seconds, it gave me a real sharp kick and the boost totally dropped. it feels like it's hitting a wall. i was able to replicate the problem and it happens each time i get into full boost. i am thinking i probably need a new fuel pump, but what do you people who actually know things think.


my mods list is- 3'' turbo back exhaust, vta bov, dynoflash, k&n filter
i peek at about 1.7 bars, which is i guess about 25 pounds of boost which i am aware is higher than the stock number, it hits it for a millisecond, and then slowly tappers off to about 19 or 20

keep in mind that i have had this set up for a while, and it never gave me a problem till just today. that's one reason i am not sure if it would be the fuel pump, since it always worked before.

thanks for the help

 

Does it happen around 4-5k, if so may be a bov that can't hold the boost, also could be plugs.

 

It sounds like you're hitting fuel cut. Are you using race gas or pump gas? 1.7 bar seems a little high to me for your mods if it's on pump gas. Or you may have just picked up a bad tank of gas and the ecu started to pull major timing. Tell us a little more.

 

You need a fuel pump. and maybe a retune... dunno, ask Al. I wouldn't be boosting that high without a fuel pump. The stock pump can't take it. maybe 22psi but not 25.

 

What you are describing sounds exactly like fuel cut. Fuel cut is dependent not only on boost pressure but also outside temp and pressure. My hunch is your boost has creeped up a bit and the outside conditions have changed. We normally see this type of post in the fall as the temp drops.

Also, you are making detonation highly probable running that high of boost with or without a new fuel pump. Your boost is probably exceeding 25psi and the gauge is not fast enough to show the peak before fuel cut happens.

Speedlimit...

 

I'm not expert but....sounds like fuel cut to me too.

If you do a pull starting in 1st and run through the gears does it do it then? If not it is probably fuel cut. Loading the car in high gear will produce more boost for a longer time than any other gear.

David Buschur
www.buschurracing.com

 

Ha! Not an expert huh? Thanks for helping him out Dave!

Speedlimit...

 

So, do you guys think I should just get a fuel pump? Or do you think that I need to get it retuend or use an mbc to make sure I don't boost so high?

It never happened before, today was hotter than usual so maybe that has something to do with it.

 

whats controlling your boost? the flash? I would find out how to turn the boost down if you don't have a MBC....then you problem will probably be solved.

 

Well, the flash is controlling the boost. I think it started to spike so much after I got the vta bov, it's an agency power one though, so I could start recirculating it, not sure if that would make much of a difference. And also, I'm not boosting so high for a long time, 1.7 bar is for less than a millisecond, it holds about 21 ish for the majority

thanks for the responses to those who have chimed in

 

Also, I got my tank of gas from QT, which I normally don't do and I've heard there gas sucks.. THat might have been what caused me to notice it

 

anyone else...

 

Isn't 25PSI a bit much for pump gas?

 

not trying to jack your post but im kinda having the same problem-- when i go over 5k in 5th gear my car jerks back like i was hitting fuel cut idk whats up with that-- my mods are apexi intake , forge bov, tuned by TT at 22psi and hksevc v- idk whats the problem, do you guys think ifs fuel pump too?

 

25psi is a little high i'm assuming, but ****. i just have the mods i listed above, i don't see why it would spike so high. would the bov affect that at all? i don't really want to mess with an mbc, which is one reason i just went with the dynoflash by al with the boost controlling feature. ah.