I am switching over from the TT ECU to an AEM v1 with e85. I just installed the Walbro 400lph e85 pump today. When I finished, I tried to start the car to make sure the pump was working, and it ran for about 3 seconds, and then choked out. Started it again, and it choked out again. I did some research, and these big pumps tend to need higher voltage to run even at idle, and the stock fuel pump ECU is not giving it the full 12v. Now, I am switching to the AEM v1, so do I need to do the 12v fuel mod? Or will the AEM control the voltage to the fuel pump all on its own?

 

tbh, i don't know.
but i did read somebody talking about how the 12v mod [may] keep your fuel pump on even in key acc mode. dunno if you know of a diy with a relay put into the mod, but just something to think about (im still looking into it...the mad na-t research list).

 

Use one of the Low Sides switches of your AEM ecu to control the relay that provide power to your pump(s). In that way , you have full control like how long to prime your pump at start up and are also off the moment you cut of your car.

 

And please hardwire your pump directly from battery ...the bigger walbro not too happy with low voltage

 

you need to wire the fuel pump up to a relay. power coming straight off the battery to the relay, then off the relay to the fuel pump. Run the ground wire from the relay to proper pin on the aem and control the relay from the aem standalone. That way you can control the pump to only prime for a few sec rather than staying on the whole time when you have the key to "on". hope that helps

 

Thanks! That helps alot.

I am also on the stock FPR. Can the stock fuel lines and regulator support ~450whp? I am unsure of how to go about running new fuel lines and regulator, so Id rather keep it stock if possible since I wont be pushing huge power.