89 S13 w/ S14 SR20DET fuel pump problem

[EnthusiastMan]

Hey guys, I've got a very confusing problem here and was wondering if you could help me out.

As the title states, I've got an S13 with a S14 SR20DET in it. Everything is swaped and wired in but I'm having a problem with the fuel pump coming on. At the fuel pump relay there is a black/pink wire that is supposed to be grounded to kick the fuel pump on. When I ground this wire out manually it kicks the fuel pump on. I've traced this back into the ECU harness and have found that it changes from a black/pink to a black/yellow wire and run to the ECU. When I hook my voltmeter to the black/yellow wire at the ECU and turn the key on, I get battery voltage. When I ground this wire out it kicks the fuel pump on. I know this is the way it's supposed to work but when I ground the wire out the fuel pump keeps running and doesn't stop. Normally they are suppose to run for 3-5 secs and then shut off. Also, if the ECU is providing battery voltage to this wire, what is supposed to ground it? I thought that the ECU would ground it because it's only supposed to be grounded for 3-5secs. This is very confusing.

[redtop91]

The fuel pump only primes for 3-5 seconds but is always on. When you flip the ignition to the "On" notch for the key, outline exactly what happens.

[EnthusiastMan]

When I turn the key to the "on" posistion, the dash lights come on and I can hear the fuel pump run continuously. Also, if I go to the engine bay I can hear fuel constantly running into the engine. Note that I have to manually ground the black/yellow wire for it to come on.

[EnthusiastMan]

Upon further inspection I found that the 12V source is coming from the fuel pump relay itself which leads me to believe that the ECU is supposed to ground this wire out. Is this true on S14 SR ECU's?

[SpeedRacer1]

I seem to remember the S14 SR only priming for about 1/2 a second to 1 second before stopping unless the car is started.