Re: fmu
Look at it and see what the ratio is. First off I don't know much about the CPI.
You might be running into one of 3 problems. I would at the problem in this order. You fuel pump can't handle the additional pressure, your FMU is too small, the injectors.
The fuel pump, higher fuel pressures allow injector to pump more fuel, but the fuel pump potential out is actually less. The best way to see if your pump is going out is to look at interior fuel pressure guage, calculate what it should be and see if the fuel pressure keeps up. The base fuel pressue is the furl pressure with the engine runing, but the vacuum disconnected from the fpr. If the bas fuel pressure is 40psi and you FMU is 4:1 and running 6 psi of boost. You should expect to 40 + 4x6 = 64psi. if its seeing less the fuel pump is not keeping up.
Ther FMU I have seen have the ratio ingraved on the top. I want to say the ratio's are changable by replacing internal spring (but I am not 100% sure). If the fuel pump is supply the proper pressure, try a larger FMU ratio to see how your AFR react with that.
I have seen some stock injectors not keep up with FMU, for instance the stock injector in some of the TPI's locked up at 80 psi. If you getting good fp & the you' ve tried larger fmu ratio's and it still hasn't help, then this is probably your problem. The fix is different injectors.
