I was on the track yesterday and my car lost all power on the straightaway. Had to get towed off the track.

Found out the 10 amp "main power relay" fuse was blown. I am using a new, modified E6X harness. The only load on this fuse shown on the wiring diagram are the four stock injectors (S4 non turbo). I ended up putting a higher amp fuse (that is all I could find at the track) and the car ran fine all day after that. The car has seen previous track days and I have never had this problem before.

I am wondering if this is common problem. Is a 10 amp fuse enough to run the stock injectors?
Should I be looking for something else or is the solution just a higher amp fuse? I believe the factory PCM uses a 40amp fuse for the injectors and powers the ignition coils too.

Thanks,
Jack

 

The stock S4 injectors are low impedance. FSM says spec is 1.5-3 ohms. Assume you have them wired without the stock resistor pack? If so, then you can figure that if all four are drawing current at the same time they would draw well in excess of 10 amps. The wire in the circuit will hold around 20 amps depending on how long the run is. I wouldn't use a fuse in excess of 20. A 15 amp should be fine. If you blow that I'd start looking for a short somewhere.

 

Thanks Chris. I really like having a standalone in the car over the factory pcm. The car just seems to have more power in all ranges. Only thing is the E6K is pretty old! Maybe I'll save up my pennies and buy the new haltech that is coming out!