Yea, don't use a 12:1...
This is just a heads up for any of you planning on using a 12:1 or even a 10:1 FMU for that matter.
I put in a 12:1 FMU yesterday, just so that I would be safe to boost, and I flooded my engine. My car died after a highway run, and I couldn't start it back up. I pulled the plugs and they WREAKED of fuel, and were really wet.
My spark is fine, and my fuel pump is fine, so I know for sure that it was just the excess fuel that flooded my engine..
I knew I would regret using a 12:1, but I did it anyways, for something temporary. I wish I would have just kept stock fuel now. My car hasn't started for a day now..
anyways, yea, DON'T USE A 12:1!!
curt
12:1 FMU = bad
-
Redline240
- Posts: 892
- Joined: Sun Dec 08, 2002 1:34 pm
- Car: 95 240sx
-
C-Kwik
- Moderator
- Posts: 8070
- Joined: Thu Aug 01, 2002 9:28 pm
- Car: 2013 Chevy Volt, 1991 Honda CRX DX
The pump doesn't necessarily pump out that much pressure. Once the pump reaches it's limit, it basically just maxes out the pressure. However the boost rise will be much higher and hit the max pressure earlier. And fuel pressure will actually dwindle down given the same boost pressure through out the RPMs as RPM's rise(more fuel demanded, same fuel pressure) once it hits the fuel pumps max. It is possible in this case that the spark was blown out allowing the fuel to dump in and flood the motor.
also for the fmu fellas i know of a lil trick if you want a lil bit less fuel. go to the local pet store and get a bleeder valve for a fish tank. put that inline in the vacuum hose going to the fmu. open it up a lil bit to let the fmu see less boost which will lead to less fuel. theyre only like $2. and you can put a check valve before the bleeder valve so when the valve is open and youre in vacuum its not sucking in air. that way it only works with the boosting situation.
now I feel like an ***
anyway, that would be a good idea, I think FMU for long term management is a bad idea, Im only running until I can get down to the dyno. I have 370cc and SAFC in my garage, just waiting to put them in. so Im not worried, the only problem is that I ran through an 02 sensor in 200 miles, and Im sure my cat is destroyed.
anyway, that would be a good idea, I think FMU for long term management is a bad idea, Im only running until I can get down to the dyno. I have 370cc and SAFC in my garage, just waiting to put them in. so Im not worried, the only problem is that I ran through an 02 sensor in 200 miles, and Im sure my cat is destroyed.
-
LongIsland240
- Posts: 118
- Joined: Fri Nov 14, 2003 7:19 am
- Car: 92 S13 Hatch
ftrs13 wrote: the only problem is that I ran through an 02 sensor in 200 miles, and Im sure my cat is destroyed.
What do you still have a cat for anyway??
The 12:1 "universal fmu" I got was a huge waste of $100.....flooded the car when i was pushing anything over 4psi, and running pig rich until that point. You can bleed some of the boost signal off of it with a cheap manual boost controller so it's effect is't so severe too...if you don't just want to get a recalibration kit. I replaced it with 370cc and an SAFC like i should have in the first place...the cost of the fmu was $30 more than i paid for a set of 370s......my .02
I think most poeple know from one experience or another that FMU's are only a temporary, low boost, option for turbocharging a car.One of my friends bought a turbo kit from hans racecraft and in the kit was a FMU that had his fuel pressure running around 110psi. All this was being fed by a inline, secondary fuel pump.What kind a company would sell such a ridiculous setup.I mean, the secondary fuel pump is sucking fuel through the stocker, and the FMU is stepping up the fuel pressure 50psi over what the lines are safetly rated for.Needles to say, he melted a piston ring, b\c one of his injectors failed! Geez, I wonder why?Like I said, temporary low boost setup!However, you wouldn't catch me ever using one of those da*m things!The first thing I bought for my KA turbo was a JWT ECU & SR 370cc injectors!Do it right, the first time!