no power to inline fuel pump, when plugged into harness

finalride · #1 06-04-2016, 04:59 PM

Hi all. new to this forum, but have used many forums before to get great advice.

ok here it goes...

1987 ranger 2.9. got it for free 2 yrs ago. my son needs a 4x4 to get to work when it snows, so we pulled it out of weeds and into garage. cranked and cranked on it after replacing battery. no start. shot with either and it fired. have spark. no fuel to motor. contacted who i got it from, he said he replaced pump in tank. tested wires at tank. 4 wire plug. got 3 negatives and a pulsing hot wire. I believe its yellow. on to inline pump. had a positive signal in the pink wire and the black wire. bad pump. replaced pump and filter. Now for the weird part.... I have a power signal on pink wire, in the plug for the pump and in the wire to that pin, with plug disconnected. When i plug in 2 wire harness on pump, power goes away. it actually shows a ground. unplug it, and power is back. I have not used a meter to check voltage yet. oh and i did put in new fuel pump relay.

Any ideas?

finalride · #2 06-04-2016, 07:41 PM

ok, I have an update,

I found a ground wire that was not grounded. Upon testing wire and touching to ground, found that it made the fuel pump relay click. so I re grounded that, but still no fuel pump when key is on. and still lose power to pump, when i plug into harness.

I bypassed the relay and hard wired the pump on a switch, just to see if the new pump was working. which it is. found the test port on the fuel rail, bled off air and vvroom. it started in less than what seemed like 3 revolutions of the motor. idled kinda rough at first, but smoothed right out. a little stumble on acceleration, but hey, its been sitting for about 4 years.

So now its down to figuring out why i lose power at harness connection. Any ideas?