Looking for some insite on alittle issue so I have been working on my oem harness again deleting unneeded wires while waiting on the machine shop to finish my motor . I went to test everything windows lights horn ect and so far everything works except I don't hear the fuel pumps prime. I have a double pumper setup it was working before so I no its some issue I caused trying this on stock ecu since I don't have my pro efi wired up yet .

My question is does the stock ecu need to see a cps signal or cas signal or any signal for it to prime the pumps ? If it does then that would explain it.

 

yes the ecu needs to see crank signal to prime the fuel pump

 

edit (from my searching the fuel pump does not prime on the stock ecu ) someone with stock ecu can you verify ?

i am use to hearing it because i have been on aem for the last two year.

Yea I figured as much with my searching I will not really be able to test untill i have the engine back in my hands it looks like I just got alittle worried with really me only touching fuel pump related wires i removed the staged fuel pump control relay and the resister box/heat shink

 

back to the top tried to start the car i am getting no fuel presssure the gauge has not moved also removed the feed line on the rail bone dry i am getting spark tho so its not the ecu i removed the fire wall heat sink and the larger fuel pump relay that says denso on it i was under the impression it was just for fuel pump speed control and it was ok to remove.

what was removed

 

Since I swapped over to a double pumper mine never primes anymore. I am on a stock ecu. I was told why it doesn't prime anymore but I forget. It was a while ago.

 

i have a double pumper as well i guess i should have added that but i am still not getting any pressure at the rail at all so i know its something i did when i removed wiring i am just trying to see if there is away around it or if i need to order a new harness.

 

Thing that would control the pumps is the mpi relay make sure that's in, also the fuse make sure its not blown. The fuse is right on the positive battery thing. I would also look and make sure when the ignition is on or cranking that your fuel pumps are getting power.

 

Definitely check your fuses if you have been messing with the wiring

 

put those pieces back in and see what happens

 

the right relay with the red wires looks like the fuel pump relay. without that you wont get any fuel at all

 

thanks for the help guys i have since orderd a new harness that i will deloom that way i trace the wires back to the right spot when i add the relay back i figured this was the easiest thing for me to do i will keep everyone up to date.

i had checked fuses and all the simple stuff before.

 

that sucks that you have to get a new harness.

 

well this was my thought process i could test this and that and spend a bunch of time just trying to rig the pumps up and trouble shoot or i could just order a new harness deloom it and see where those relay wires run then go back and add them to my harness and be on the road and maybe down the road ill start building a new harness.

wish me luck it will be here tomorrow

 

Just to update the thread I got the new harness thursday spent a hour taking the factory loom off and tracing the 7 wires they all run into each other then turn into two larger wires and end up in the underdash plugs ontop of the ecu only one of the wires runs into the ecu anyway car started up right away it might have ran on aem ect but as far as the stock ecu goes do not remove.

 

after reading this thread i was scared installing my buschur double pumper and 1450cc FIC inj. Installed everything and car fired up just fine. i'm lucky i guess