Hey guys, I have a S5 engine in my FB and starting that thing is a bitch. The only way it will start is if I short out the check connector for priming the fuel system. Once that happens I can start the car, but if I let the thing idle for a while it just drops lower and lower and eventually dies. Then its impossible to start without shorting out the fuel pump check connector.

I'm using an inline GSL-SE fuel pump for my fuel system. The other thing that might indicate what is going on is that there is never a pressure release when I remove the fuel cap.

So can anyone tell me what is going on here?

 

bump

 

what harness and ecu are you using?

I guess you just have a problem in your wiring or screwed something up during the conversion.

 

its the stock S5 ecu and harness. Apparently the problem is it looks like I have a bad water thermosensor. That would release the fuel pressure when the engine is off, making it impossible to start.

 

what happens if you pull the jumper out right after starting? does the pump stay running?

 

*****That would release the fuel pressure when
the engine is off, making it impossible to start.******

I don't think things work like that. I suggest, like above, that the wiring to the fuel pump is miswired. I'm not saying the pump isn't running, just that the switch in the afm isn't keeping the pump running. For whatever reason.

On a normal car, when you put the key to START, a relay is pulled in that feeds power to the fuel pump. When you release the key from START...the relay is de-energized and power is cut off to the fuel pump. UNLESS the car actually starts. Then a switch in the afm keeps the aforementioned relay pulled in and it keeps feeding the fuel pump. Your car isn't normal.