S5 motor on s4 ecu???
 

I been having alot of trouble wit my 87 turbo 2 when Mass is pluged in the motor starts then dies. When its unpluged the car idles just fine....shit is weird. I think it dies because it gets too much fuel so it dies. Come 2 find out the guy i brought it off wired the s5 engine in the s4 harness and ecu!!! I want to know will that have a effect on the injectors but the s5 are bigger then s4 and can i just put s4 injectors in with out doing the harness all over?

What is a "Mass"? AFM? Massachusetts?

S4 & S5 injectors are not different sizes. They're all the same as long as the model is the same (NA or turbo). If the S4 electronics were used on the S5 keg, there's no issue with having an S4 harness and ECU controlling things. But if it's a mix and match hodgepodge, you can bet your problem is somewhere in the spliced wiring.

There is a different size injector for the s4 they are 440cc and the s5 is 550cc i think it dumps too much fuel in when started that why it bogs out. rite?

U ever herd of something like this before

s4 and s5 injectors are the same besides impendince.

No. S4 & S5 NAs use 4x460cc injectors and S4 & S5 TIIs use 4x550cc injectors. There is no difference in flow between series.

The AFM also has no control over the amount of fuel on startup. That's the ECU all the way.