I have a p28 ecu that is chipped and my fuel pump is not turning on. First off I switched ecu with my stock pm6 and heard my fuel pump turn on and it ran so I know its my ecu and nothing mechanical. From what I've seen this is a fairly common problem with these ECU's so my question is what exactly controls the fuel pump I thought it was just one capacitor that was he problem with those because before now the last few times I started it it might take a minute or two for my fuel pump to kick on but now it just won't at all and my buddy has the same problem where his computer sometimes he has to wait a few minutes for his fuel pump to kick on but someone else told me there is two things to it that cause your fuel pump to not turn on so long story short does anyone know what two things it is that causes it or is it just the capacitor and what capacitor exactly is it?

 

It's either a bad solder job or a bad chip. QM3 signals the main relay from RM7 (there is no cap), but I sincerely doubt that's not your problem unless you roasted your injector drivers or shorted your A\C clutch circuit. Re-solder the chip section first.