No Fuel pressure

[JH4020]

I have an 89 MJ with no fuel pressure. The Harness at the pump only shows .35 volts. What do I need to be looking for?

[onlyinajeep726]

Start with the ballast resistor on the driver side inner fender, next to the air box.  It's white and has two orange wires with black tracers, on either end.  Jump those two wires together and see if that makes a difference.

 

Pic for reference:

[cruiser54]

Nice pic!! Where'd ya get it?  LOL. 

 

Snag the one below if you want.

 

First place to look. It's okay to bypass the resistor also. 

 

Fuel pump relay could be it also. 

[JH4020]

Replaced ALL four relays. Jumped the Resistor, still no luck. The plug-in going to the fuel pump only shows .35 volts what else?

[Megadan]

Checked the ground at the tail light?

[cruiser54]

Checked the ground at the tail light?

Hmmm. Good idea. 

[JH4020]

I di re-do all the grounds. What next?

[HOrnbrod]

 

Checked the ground at the tail light?

Hmmm. Good idea.

Last I heard the Renix pump doesn't ground at the tail lamp.

[cruiser54]

 

 

Checked the ground at the tail light?

Hmmm. Good idea.

Last I heard the Renix pump doesn't ground at the tail lamp.

 

Driver's side inner fender under a sheet metal screw. 

 

Time to start chasing the power. Is there power at the resistor? How much? 

[JH4020]

Nothing to Resistor. 

[cruiser54]

Pin 30 of the fuel pump relay receptacle? 

 

The flat 6 wire connector on the passenger inner fender. Unplug and check the connections. Solid orange wire is fuel pump power.

[JH4020]

Thanks, I'll try that tomorrow.

[cruiser54]

Keep us updated. 

[JH4020]

Ok, I have power to the Relay pin 30. Flat harness looks fine, cleaned it up good. Still nothing. Turn key and hear a clunk at the tank, but that's it.

[cruiser54]

Ok, I have power to the Relay pin 30. Flat harness looks fine, cleaned it up good. Still nothing. Turn key and hear a clunk at the tank, but that's it.

How much power? 

[JH4020]

12 volts. Getting none at the fuel pump connection.

[cruiser54]

Key on, What's 86 read?

[JH4020]

12 volts.

[cruiser54]

Okay. From there it goes to C103, the flat connector I mentioned earlier. 12 volts there? 

 

Then to C100 which is the connector behind the fusebox that lives in the engine bay.

 

Then to C119 which is a 10 pin connector behind the driver's side kick panel.

 

Then to the fuel pump connector. 

[JH4020]

Thanks, I'll give that a try in the morning. Will update what I find. Thanks to all ahead of time who take time to help with everyone's problems. This jeep is a whole new game for me, I'm usually messin with my TJ and Brute Jeep.

[cruiser54]

Thanks, I'll give that a try in the morning. Will update what I find. Thanks to all ahead of time who take time to help with everyone's problems. This jeep is a whole new game for me, I'm usually messin with my TJ and Brute Jeep.

Hang in there. 

Brute Jeep is one of those electric kid's Jeeps, right? LOL Just messing with ya. 

[JH4020]

Alright, with the C103 unplugged, I have nothing at the Relay 30 pin. When you say power to the C103 do you mean to the solid orange wire? Confuzing!!!

[cruiser54]

Leave it plugged in and check C on the c103, orange wire, while plugged in. 

[JH4020]

Nothing on C.

[JH4020]

Still working on it, not giving up yet. Think I may have it figured out. With the relay jumped I got power to the fuel pump connection. So now I'm thinking pump. Today I ordered a Bosch 69302 pump, Airtex FS104 strainer, and Spectra LO01 lock ring w/seal. Will be here Friday, hoping that is it! Thanks everyone for your input.