ok so i am running really rich, to the point where under normal driving black exhaust gas is noticably coming out of my exhaust, and when i floor it i get a big puff and a fair bit more smoke. so what can i do to lean it out a little? i heard there is a way to trick the fmu by putting pinholes into the vaccume line that goes to the fmu, is this true? in theory it should work but has anyone here done it? any other ways to lean it our a bit? thanks

 

i'm not sure about the pinhole method but if you think of the fmu in a similar manner to the wastegate(both pressure sensitive devices) then you could put one of the little brass cheater valves that are so often used for "boost controllers" in there. just put a tee in the vacum line and have the third nipple from the tee go to the bleeder valve and you can adjust how much pressure it relieves. It would work. not the safest or most effective method but cant beat the price. FMU 100$+ controller 3$.

 

hmm, interesting... its similar to the pinhole trick too, just letting a little air out to trick the fmu. anyone else?

 

why dont you just get a used safc, the pin hole trick may work but it might lean it out too much and you dont want that just my .02

 

well if you use the little boost controller valve you can close it all the way and run the fmu as it normally would. start there and then just open the valve 1/4 turn and try that, then another....etc till it gets just right.
all the way open w/ a check valve and the fmu would run as if it was a stock regulator and not read any boost just vaccum.

 

whats your fuel set up,if your running that rich,maybe you dont even need it.