my friend install V8 in is 88conv with 92 harness , he have a problem of no start , spark make a poor red fire , and injector don t blink , and i cant find wiring diagram for 92 .. only 89-91 .. i got a ground connector on my 90 5.0 just near the starter solenoid (2 wire , on from neg battery and the other from a black connector) , he said , he dont have the black connectro ground ,but this wire is plug on the solinoid , when this wire is not connected to solenoid , fuel pump does nt work , seems weird to me , ...

 

I think I know what you're talking about, but can you take a picture of the two wires and let me see? This way I can give you a proper guide on what to do.
SS

 

 

That wire has to be grounded on any EFI Mustang from 86-93 for the fuel pump to work. Also, make sure that the orange wire on the Engine Harness is properly grounded to the block as that is the computer ground. There is also another computer ground wire inside the car in the kick panel area, its supposed to be grounded with a green 7mm bolt and it is a bare wire with a round connector at the end. I'm a bit tired and I have to be up early tomorrow morning, but try the above and let me know how it turns out and we'll go from there.
SS

 

did your friend change only the engine harness to a 92, or did he change the harness in the whole car?

 

entire car harness .