So I am kind of at a loss right now on this issue. I am not getting power to my fuel pump, I turn the key and get power at tthe ballast resistor for about 2 seconds and then nothing. I have checked power to the relay, it's good, check relay and it's good with no resistance, balast resistor tests 2 ohms. I refreshed the fuel pump ground at the tail light. I have read alot about CPS issues, but can that cut power to my fuel system?

Thanks in advance for any and all tips,
Mike

 

Start by checking through this list, do any and all steps that might apply to you're situation.

https://www.cherokeeforum.com/f51/cr...x-tips-153657/

Just to clarify, you are saying you checked and you get zero volts to the fuel pump? The older gents are going to ask you what you have done so far, so don't forget. Welcome to the forum.

 

I still need to check at the top of the pump, but I get power for 2 second at the connector before the pump.

I have went through the grounding portion of that list. I added a new negative cable, refreshed all grounds on the dipstick stud, refreshed the tail light ground for the fuel pump, and refreshed the engine to chassis ground at the firewall.

 

You will only get power for a few seconds to prime the system until motor starts then power will be constant .. Does pump run those few seconds ?

 

Move all the relays over one socket.

 

Evening Major.

 

Evening General.

 

I do not build pressure in those 2 seconds it has power and I cannot hear it run. Pump does run with power wired direct to it though. I will try moving the relays all over, I did check the relays on both sides of the fuel pump one while I was checking it. But I will give it a quick shot anyhow. Thanks!

 

If fuel filters not the issue. Sounds like pump time .

 

How's the wiring going back to the pump & connector?

 

So, i just got home from work and tried a few more things. I checked power going directly into the fuel pump, same story with 12.5V for 2 seconds then down to 0.5V. I tried this after shifting all relays down one slot as cruiser suggested and same story. Wiring appears to be in decent shape. I also checked for spark to rule out the CPS, and I am good there as well. Fuel pump is brand new, and like I said works when power is supplied directly to it. When I did have it wired direct, it was outputting 42psi at the rail. Which if I am not mistaken is high. Another side note on that subject is that when I would turn the key off, I did not hold fuel pressure. I have no external leaks.

 

Does it run when wired directly ? Have you tried bypassing resistor yet ? What brand pump ?

 

That scenario sounds like there is resistance in the wiring or connectors someplace. 12 volt power back there without a load from the pump, but not when the pump is connected. In other words, enough current to indicate 12 volts on the meter, but not enough to run the pump.....

 

Or bad pump ground....

 

Well I got to the bottom of it... found the sending unit wiring wrong. Does it tell it not to turn on with low fuel or something? Anyhow got it started and had fuel coming from the vacuum side of regulator and had 40psi, so I ordered a regulator and am hunting for a sending unit. Sorry for the delayed response, went to the ballgame today