Stock T25

[AMPPRC]

my boost gauge is saying 15LB of boost at WOT and i am now hitting fuel cut. i do not have a MBC on it so why is it running at the hi of boost?

 

[my dreamt dsm]

http://www.dsmtuners.com/forums/frequently-answered-dsm-questions/186971-what-fuel-cut.html
Some cars are different. I'm doing 17psi and my car is running fine. Mods in my profile. Logged on Evoscan.
Could be your exhaust system is causing your flow to spin the turbo faster since you have no restrictions. That is if your mods are up to date.

 

[CanMan]

Mine is the same PSI, less the fuel cut. I had a MBC on it but took it off. Fuel cut was at 17-19 for me with the MBC.

 

[Absit]

Fuel cut has nothing to do with the actual fuel system.
Check for boost leaks.

 

[DSM teen]

If you want to reach any boost level higher than the 15-19psi range you will need to upgrade a few things. This is what I have done to prepare for it. Buy a Walbro 255lph, this will prevent fuel cut. It is advertised to handle 500hp. Next to handle the higher fuel flow you will need an aftermarket afpr. I used AEM and it has worked really nice (A fuel pressure gauge will be needed to set your base pressure). The next good idea will be to buy a wideband air fuel gauge. This will let you know to back off the throttle because you're driving lean before you break something. Lastly larger fuel injectors a larger fuel rail to hold the injectors, a larger turbo (Garret GT30) (my after college project ) and some tuning software.. I suggest Open port by Tactrix.. It is a nice alternative to DSM link that will save you money.

 

[Sirius Spyder]

Before you run out for the 255Lph Walbro make sure the goals for your car require it. Going with the 255 means you'll need that adjustable fuel pressure regulator. You can save some time and money by dropping the 190Lph in if that's all your setup requires. I'm running the 190 with 680cc injectors with no problem.

 

[JusMX141]

my boost gauge is saying 15LB of boost at WOT and i am now hitting fuel cut. i do not have a MBC on it so why is it running at the hi of boost?

Sounds like your boost control solenoid is defective....although you shouldn't be hitting fuel cut at 15psi with a T25. I think you have a boost leak.

I know of someone who is currently trying to kill his T25, spiking to 22psi and dropping / holding around 15-16psi to redline...all done on the stock fuel system. I don't condone this at all, but I do think you have some type of issue.

 

[brian9397gsx]

Like stated before me, you may have a boost leak. I.E. your maf is seeing more air then is making it to your intake manifold.
Hope I worded that ok

 

[AMPPRC]

alright ill check for boost leaks. could that also cause a p1105 code?

 

[JusMX141]

Not necessarily, but a defective fuel pressure solenoid could be what's causing your fuel cut. Here's how.

The fuel pressure is intended to raise at a 1:1 ratio with the boost level. If your base fuel pressure is 43psi, your fuel pressure at 15psi of boost should be 58psi. If the solenoid is screwed up and is not allowing the fuel pressure to rise at the 1:1 ratio, there's a good chance you're only at 43psi of fuel pressure at 15psi of boost. The AFR's go lean, the ECU senses this, and the next thing you know you're biting your steering wheel in the middle of a pull.

 

[AMPPRC]

Not necessarily, but a defective fuel pressure solenoid could be what's causing your fuel cut. Here's how.

The fuel pressure is intended to raise at a 1:1 ratio with the boost level. If your base fuel pressure is 43psi, your fuel pressure at 15psi of boost should be 58psi. If the solenoid is screwed up and is not allowing the fuel pressure to rise at the 1:1 ratio, there's a good chance you're only at 43psi of fuel pressure at 15psi of boost. The AFR's go lean, the ECU senses this, and the next thing you know you're biting your steering wheel in the middle of a pull.

is there any way to test the fuel pressure solenoid? and where can you buy new ones.

 

[JusMX141]

There may be, but I'm unaware.....and the Mitsu dealer.

 

[AMPPRC]

There may be, but I'm unaware.....and the Mitsu dealer.

yea dealer is wanting $75 for one

 

[Absit]

It's a solenoid, apply power and listen for a click. More accurately, apply vacuum, apply power, check for a change in vacuum on the other end.

Edit: JNZ has it for $57 (P/N MD113721)

 

[knochgoon24]

I'd look for a boost leak. Fuel cut is based on mass air flow. With a post-turbo leak, you'll be flowing more air than usual at only 15psi, which would induce fuel cut. Do a boost leak test.

One way to test the solenoid is to just bypass it. Run the vacuum line straight from the intake manifold to the fuel pressure regulator. If it fixes your problem, it was the fuel pressure solenoid. Doubt it though.

If it went lean and knocked (due to a bad fuel pressure solenoid), it would just pull timing and dump a bunch of fuel to stop the knock. Much less violent that fuel cut.

 

[ssicb]

my fuel pressure solenoid is bad and i have no problems on stock boost. .02