Hello all,
I've been lurking for some time and seems like a great site......great to be here!!

Of course I have a problem with my 98 D1, 202,000 miles......I've searched extensively, but still need some thoughts. Okay, here we go:

-fuel pump won't run with the harness connected (currently hot wired to my trailer harness)

-here is the crazy stuff......I have power at the harness, 12v on the purple/white wire and 5v on the gage pins.

-turn the key to position 2 and the voltage drops to zero after 10 seconds (just like it should)

-I have power at the multifuntion relay and at the inertia switch (switch is not popped)

-all grounds that I could find are good

-all harness connections are good

-all fuses are good

-rebuilt pump with new airtex E3270 pump....

any help would be appreciated...........

 

Did you replace the pump, or just rebuild parts of it? There is a fuel return valve on the pump, and it if runs when you switch it on, but then the pressure drops to zero, this valve is probably the culprit. Unless you replaced the whole pump, it might still be the problem...

 

Your pump is only designed to run for 5 seconds before the ECU shuts it off if the engine won't start.
What happens if you turn your key 3 times to the 2nd. position, hold it for 4 seconds, turn it off then try to start the engine?

 

nothing happens when you turn the key no matter how many times that you try..........I am current driving the truck with the pump hot wired so it is not the pump. Per my previous post I have troubleshot everything that I can think of!!!

 

You stated in your first post that there is power to the pump for 10 seconds when you turn the key on. Are you saying the pump won't turn on when it is plugged in?

I also asked what you did to the pump......you stated you rebuilt it? How so?

 

When hooked up correctly the pump wont run.
But you have power to the pump.
When you hot wired the pump did you splice the wiring or fab a conector?
It sounds to me like the pump harness is bad.

 

-I installed a brand new pump only into the original housing

-hot wired to my trailer wiring harness (must turn lights on first then start) the pump will not operate with the harness connector attached

I guess I will go into the wheel well and jump the pump harness to see if it is that.............

Thanks for the replies..............I'll post back

 

The new pump went into the old housing, including a new wire harness?
I guess that is where I am confused.