recently did a engine swap from an 88 s4 to my 85 s4.
everything is plugged up and ready to roll but.... getting no power to the fuel pump so the car aint' starting.
have temp hooked up a permanent feed to the pump but its still not starting.
compression in first rota 92-95psi and second had 100-105.
spark is there, it does fire up for a second if fuel is put in the intake.
im thinking there is a difference in the wiring on the two cars. can you point me in the right direction. ive also tried to find a diagram of the ecu to see if there is any output to the injector but cant find any. (mabye im a bad searcher)
any help would be appreciated.
Nick

 

there shouldn't be a difference in the S4 wiring setup. The first thing i'd do is hot lead the fuel pump to a constant power source and see if it clicks on. you could have a loose ground or something too. How old is the fuel in the gas tank? That could also be a factor.

If it's a fuel related issue, chances are the solution will be straightforward. Start with the fuel pump diagnosis first. then work your way towards the engine. Check your lines, fuel filter and your relays.

 

bad fuel may be an issue. the fuel has been in there for a while. what relays should i check and where exactly are they?