today i just put in rc 310's and a walbro 255....running a stock dx ecu with a fmu, boosting 10psi. b4 i put in the injectors and pump, it would break up and bog when it hit 10 psi...now that i put the injectors and pump in, its doing it at about 5psi...what could be causeing it? the stock ecu? they injectors are used also...maybe the timing with the new injectors? about how much should the distributor be pushed forward, since i dont have a timing light
it seems weird that this happens now when i thought it would solve the problem, not make it worse
my a/f gauge stays at almost full rich now at idle, not bouncing like usual, is this normal with bigger injectors?

 

Ohh lord . Well first off the ECU needs to know that you have bigger injectors so you don't throw more fuel then need be. Next I can't believe that you actually are looking at that little light so you car a a/f gauge. If the a/f gauge is bouncing it's because you are in closed loop, in any case this still means you are running a narrow band o2 sensor . You need to get to a dyno and get your car chipped. It the only way to run bigger injectors (minus the afc hack) and not run richer. The bog coul dbe anything, you could be leaning out, you could be having bad timing. Why are you running 10 psi on an FMU. DOn't you know that puts WAY to much strain on the injectors!! you are running of 100PSI of fuel pressure through each injector. I'm sorry to say you are off to a bad start and I hope your engine will last. Please get it tunned by a professional or get the necessary hardware to use bigger injectors/10 psi of boost

 

you are probably dumping in a shitload of fuel

 

aight thats what i figured...i hve a chipped ecu on the way, shouldve been here today or tomorrow...thats why i got these in today, so tomorrow i can plug and be good hopefully..i got it programmed for the bigger injectors, nd im ready to go with uberdata also

and i know i know the 10psi on the fmu is a no no, but thats what my turbo is hitting...no boost controller, and the wastegate arm is extended as far as possible

anyway thanks guys

 

I agree with adseguy.

The problem might be you leaning out. I had that problem with my car, when I had the FMU and stock injectors (crazy high fuel pressure) before I went standalone.

By the way, what kind of spark plugs are you running with the turbo setup?

 

stop boosting the car

Sell the FMU and get your Socketed ECU ready for Uberdata

when you have a decent BIN file for your Uberdata then do some wideband street tunning, when you get the a/f's right go to a dyno and fine tune it from there.