i have a b16a and i just installed a turbo. i have an fmu right now (yes, i know they suck but it's temporary). my problem is that after the car boosts a couple times it seems to be getting way too much fuel. the first couple times after i start driving the car will be smooth and fine but then around the transition into boost and sometimes during full boost it will bog down. i know that the fmu will make it run rich but should it be to the extent where it makes the engine bog down? my static fuel pressure is like 42 psi with the stock regulator. i'm not concerned with it running perfectly right now, i just want it to run smoothly when boosting. any suggestions are apprectiated, thanks.

 

Get it on a dyno and have it tuned.

 

Thats shitty advice, considering its impossible to tune an FMU on a dyno, unless by get it tuned you meant ditch the shitty fmu and run hondata or uberdata.

What is the FMU disk calibrated at? Some more info on your setup would make it easier to help you out. Is everything else in the fuel system stock besides your fmu?

 

sorry, it's a 12:1 vortech, stock b16a, t3 .48/.42 turbo, i have the stock fuel pressure regulator, stock injectors, just the fmu. should i try bleeding off some air to the fmu to see if it runs better? my air/fuel gauge reads all the way rich as soon as the turbo starts to spool. i don't know that much but it seems that it's getting too much fuel. what should the static pressure be?

 

Well ditching the FMU would be a start, but I was figuring he had a way to adjust fuel pressure. The only way to REALLY tune a car is with a wideband. Sorry for my shitty advice, but that's the way I'd do it. I wouldn't want to risk a motor with a "butt dyno" or plug checking tune. I would want to know what kind of A/F ratios it was running.

 

ok first off a FMU is totally tunable infact my set up has pushed cars to 10's......first off those autometer AF gauges are nothing to tune with....get a EGT gauge and also a afc at least....step to to 370cc injectors and get it on a wideband

 

Gee, I guess I do know a thing or two huh?

 

i know that i need better equipment to properly tune, but i'm wondering why my car stumbles when boosting. does it sound like too much fuel to you guys?

 

Check your spark plugs and see if they are black/smell like fuel.

 

I dont care what your setups have done on FMU's, they are NOT tunable, bottom line! With a 12:1 FMU, there is no way to tune it, it simply increases fuel pressure by 12 psi per pound of boost the FMU sees. That means if your static fuel pressure is 42 psi or whatever you said it was earlier, and youre running 7 psi, your fuel pressure would be = 42 + (12x7) = 126 psi

The problem with FMU's is that they cause extremely inconsistent fuel curves, some spots might be extremely rich like you mentioned, while others might be extremely lean. And as Im sure youve noticed, this causes a jerky transition into boost. Ive run both an FMU and a standalone on my setup, and can tell you flat out, I will NEVER again use an FMU, no matter what the financial situation is, because of how easy it is to chip your ecu and run crome or uberdata. Pay an electronics shop a few bucks to chip your ecu for you, get PHiZ to send you a map for your setup, and buy some DSM 450cc injectors for under $50 and youve got yourself a solid fuel management system. That setup mentioned above has been proved time and time again to be reliable, safe, and make good power.