Hi,

E11v2, v1.89 build 32

I am using 2 walbros, each feeding a fuel rail.

I have each of the pumps wired through an OEM FD fuel resistor.

I use the aux fuel pump function to turn on a relay that feeds +12v from the relay to the pump. When the relay is grounded, the fuel pump sees +12v. When the relay is not grounded, fuel pump voltage is through the resistor. This is the same set up for stock FD.

Each fuel pump has its own relay and resistor. However, the ECU grounds both relays when aux fuel function is activated. The setting to turn on aux fuel pump is -.7 psi, 3000 rpm. I use aux 2 output for this function

98% of the time, this system works very good. When I turn the key on, I can hear the pumps start out with low voltage (via resistor), then the ecu kicks in to ground the relays momentarily, then back to low voltage. The ecu cycles like this everytime during priming.

2% of the time, the ECU does not cycle as described above. The pumps stay on low voltage during priming. When this happens, the car will not start even though fuel pressure is where it should be (30 psi). I get sparks on all rotors, I can smell fuel in the tail pipe and there's a small puddle of fuel under the car (leak from vband exhaust).

I cut power to the ecu, restart and it works as normal.

What's up with that?

Thanks for your thoughts.

 

Well fuel out the exhaust is something to look into separate from the fuel pump thing...but try setting the load trigger to -1.5 and try increasing the the transition time as well.

 

Observation! If you're running 1.89 software, but your ECU has build 32 firmware you are in trouble and thats the reason for your issues. You need to have build 35 firmware in the ECU to use it with 1.89 otherwise you could run into other more serious functionality issues.

I also suggest that when you do upgrade the ECU's firmware you DO NOT use the current map you have, make a new one out of the default base map found inside the program folder, you can open a 2nd instance of Halwin with the old map and copy/past the fuel and ignition maps to the new map using the text tables, just highlight the entire tables and hit 'Ctrl + C', then 'Ctrl + V', and manually change all the settings. This will guarantee your new map is done on the right software/firmware and will work normally, im sure the problems will subside.

Also, walbros need to have their own independent power and relay lines, of good gauge or they heat up and can fail, you might want to consider that too just in case. What fuel pressure regulator are you using?

 

Correction, I am using build 35.

FPR is Aeromotive 13109.