Car has been sitting for a few weeks. Got my timing back on and went to start it but the fuel pump is not priming. Solid CEL with no codes via jumper service and Neptune RTP.
I have swapped out main relays and tried two different ecus. Only thing I have not switch back out is the fuel pump since I only installed a Walbro 250lph fuel pump not so long ago "less then a month" and everything was working normal. Any ideas? I'm stumped

 

Have you checked the 3 fuses related to the PGM-FI Main Relay yet?

With out the MM&Y of car I will assume it is a 97 Teg, if so...

Drop the PGM-FI Main Relay and test the yellow/white lead, it should be hot at all times, fuse 31-15A.

Test the yellow/black lead, it should be hot in run and start, fuse 24-15A (20A if it's a GS-R).

Test the blue/white, it should be hot during cranking to start only, fuse 18-7.5A.

Test the black lead, [may be two leads same terminal] should test as ground, full continuity to chassis ground.

Test the yellow/green, fuel pump power lead should be hot, [12V+] for a few sec. after ign. is turned to run.

If all is good but no power on yellow/green, use a jumper lead to supply a ground to the green/blue, if the pump runs test IPG1 and IPG2 at ECU/ECM, should be the only two yellow/black leads on the ECU/ECM plugs, they should both test as hot, [12V+] when ign. switch is on.

Let me know what you find. 94

 

97 Acura Integra GSR. I have checked the main relay and all fuses under the dash and fusebox in the bay which I have relocated under the dash.

 

I had a similar problem and the culprit was the ground wire that is connected to the thermostat housing.

 

yes. check the ground.
and you could try running direct power to the pump. if it doesn't come on, try direct power and ground. if it comes on then, it's a problem with the ground side

 

How did you check the fuses, did you just eyeball them or actually test them under load?

You said, "I have checked the main relay" how did you do that, just swap in another one?
Have you checked the wiring to the PGM-FI Main Relay plug, like I suggested? 94

 

I checked my ECT ground and it's not the problem. I eyeballed the fuses, none were blown so I figured it wouldn't be the cause.

I switched the main relay with a known good one. I want to test what you have posted but am kinda confused. Never was an electrical guy

 

do you have power going to the pump on of my eg's had the same problem had a short in the yellow and green wire under the dash going to the brown plug check for power at the pump

 

1) White/yellow wire on pgm-fi main relay read 12.*** volts
2) Yellow/black wire read 12.*** volts
3) Could not test since I was the only doing it.
4) Not sure what you mean???
5) Had no power on yellow and green

I will try the jumper to the green/blue wire and test IPG1 and IPG2 at the ECU.

 

have you tried just running 12v to the pump directly? 12v and ground?

 

No, not quite sure how to do that actually. I don't want to burn up any wires. Care to elaborate?

 

4) Make sure the black lead is a good ground.

No power on the yellow/green, [fuel pump power lead] is because fuel pump relay is not turning on.

Power on the yellow/black indicates fuel injector relay is good and turning on, also meaning the black/yellow, [fuel pump power input] lead is good, [fuse 24].

Supply a ground to the green/blue lead, [ign. on and relay plugged in], if pump does not run, use the jumper to jump from yellow/white to yellow/green, [ign. does not need to be on and relay does not need to be plugged in]. 94

BTY you do not need to worry about #3 yet.

 

Alright, I will give that a try. Thanks for the help

 

4) Connected a wire from black lead to chassis ground made no difference

Ground from green/blue also made no effect; jumped yellow/white to yellow/green with ignition on/off also with relay plugged in/unplug made no difference as well.

 

Both yellow/black leads at the ecu read less than 12v's. Both are at 11.8**v's

 

If you jumped from yellow/white, [12V constant, fuse 31] to yellow/green, [fuel pump power lead] and nothing happened, [fuel pump did not run] then either the fuel pump is N/G or wiring, [yellow/green] between PGM-FI Main Relay and fuel pump is bad, or fuel pump ground is bad.

To test you will need to pull the bottom of the back seat out to access fuel pump power lead and ground plug.

Once the seat is out and you have found the fuel pump plug, jump the yellow/white to the yellow/green, [at the PGM-FI Main Relay plug] again and test the yellow/green at the fuel pump plug, it should be 12V+, if so, use a jumper to supply a ground to the fuel pump ground lead, [black/white], if pump does not run, replace it. 94

 

I have my stock pump, I might just throw it back on to test it out.

 

try checking ignition switch had same problem reacently and that fixed it

 

Is it even possible to check if a ign. switch is bad besides replacing it?

 

The back seat has been out. Just contemplating on taking the fuel pump out or not. Maybe the Walbro 255 took a **** on me.

 

That's why you check for power on the yellow/green at the fuel pump plug, if you have power and you supply a ground, [at fuel pump plug] and fuel pump does not run, then replace the pump. 94

 

replace only once the problem has been identified. always

 

So I jumped yellow/green to yellow/white. Checked for voltage at fuel pump and it only showed 11.8v or so. Bad power wire [yellow/green]?

 

11.8v is adequate.
pump is bad

 

Alright so I replaced it with my old fuel pump and now with yellow/green and yellow/white jumped at the main relay the fuel pump is now running continuously. But when I go set the ignition to ON position fuel pump will not prime.