club.liberty.asn.au

Hi guys,

I have an 04 GT wagon (auto) and unfortunately it's made my happiness go away

All was well until a few days ago when my wife started it and reversed out of the garage and it started idling really rough, just like it had dropped a cylinder or two. It did this for about 20 seconds, then died only to not restart.

It cranked fine but couldn't hear a fuel pump. So to be sure it was a fuel issue I started it on Aerostart....no probs.

So then I pulled the back seat out and checked the voltage at the pump, it has 12 volts. So I blame the fuel pump.

Get new pump and filter, pull all apart using adhar"s guide (props) and reassemble. All good. Put in, start car, smiles all round. Let run for 10-15 mins no probs.

Turn off, let sit for 5 mins, restart, put in drive and move forward, stop and put in reverse and it stalls. AARRGGGGHHHHHH!!!!! Try to restart, no joy. Fuel pump is not working again. So I test for power, still there. WTF?? I think maybe a connection had not been pushed together properly. So I remove pump again (this time fuel goes EVERYWHERE!) and check electrical plugs, all seems fine. Put back in tank and tighten it all up. Turn key and it starts. What the hell. Turn on and off ten times with no probs. Drive car into garage, no probs.

Go to start car for work this morning and fuel pump doesn't power on. I check for power at the pump and it still has power but it just will not operate.

So where to from here?? Could it be a bad earth? Or a faulty connection in the pump housing?

I have a few other ideas but I'd love some input from you guys if you've got any ideas. Let me know if you need more details.

Also if anyone has a wiring diagram for the fuel pump I'd love to see it. I can find the power cable and I'm pretty sure the earth is right next to it but I'd love to verify this.

Cheers in advance, Mike.

Did you check the negative side of the pump?

If this is putting out 12v it will neutralise the fuel pump's positive voltage. These pumps work on a variable negative / earth through the fuel pump controller

I've checked all 4 wires going in to the pump and can only get 12volts from one of them. I think the one next to it is the earth but not certain. The other two I think are just sender wires. When I tested for continuity through the pump with no power I couldn't get anything through what I think is the earth and power. Is this right? That's why I need a little help with a wiring diagram.

It's possible it's your fuel pump controller. If you're replacing it, you should put in an STi fuel pump controller, as the standard one will drop 1-2V

http://opposedforces.com/parts/info/22750AA010/

Also this giant thread: http://legacygt.com/forums/showthread.p ... 43860.html

I'd start with running a new (higher guage ideally) power wire, and running a new earth wire, and attach it to the controller for now. I'd see if it re-occurs, then if it does, try bypassing the fuel controller and just run the pump with ignition. If that works, replace the fuel pump controller with the part above.

That said, it might also be a failure of the loom to the fuel pump controller and it's shorting out on something or similar.

I had this same problem with my 2005 Liberty.
My problem ended up being the fuel pump housing side of the plug. The little positive terminal had completly eroded and was stuck in the plug of the vehicle loom.
It can be hard to figure out if you don't know what you are looking for. Sounds like you may have a similar problem as when you push the plug in, it may be reconnecting the terminal to the housing temporarily.
I ended up purchasing a new housing and flicked the little terminal out of the plug and gave it a really good clean with contact cleaner.
No problems ever since.

The fuel pump control module regulates the fuel pump voltage by varying the earth voltage (negative wire to fuel pump).

To test it with voltmeter, put your negative voltmeter terminal on the fuel pump earth wire and positive to positive. If no signal then earth is not working.

Thanks guys, some good info.
I can find that the fuel pump controller is inside the rear quarter but any help on which side before I pull the boot apart?
Cheers, Mike.

So I've tested the earth at the pump and it seems fine.
I've found the pump controller inside the passengers side rear quarter panel. It's located in such a convenient spot
Now I have searched the forum and the logical places in the car, and i cannot find the bloody fuel pump relay. Can someone please point me to it or is it a right of passage?

Passenger front seat footwell kick panel if I recollect correctly.....

Yeah that's what I thought so I've been in there and there is nothing. I have found the computer and the Uni chip and heaps of wiring but no relays. Is there a chance the Uni chip replaces the relays?
Disclaimer: the chip was in the car when I bought it. I'm not a huge fan but it's there so I left it alone.

So I found the fuel pump relay. A small victory i know but for all those that didn't know like me. It is located in the passenger side above the kick panel. There is a small plastic panel on the side of the dash that has an air bag sticker on it. It pops out and the sneaky little buggers are in a hanging out in there in a pack.
Now to start testing...

So your earth at the fuel pump was getting variable voltage?

dr20t wrote:So your earth at the fuel pump was getting variable voltage?

Yep all is working as it should be. A mate who is a mechanic came round and checked with me and the pump is getting everything it needs. However there is no circuit through the pump. Wondering if there is a bad connection inside the pump module itself. Either that or it's a faulty pump which I know is incredibly rare but anything is possible.

Tomorrow after work I pull the pump out again to check the circuits and wiring.

Cheers.

Right Hand Drive Turbo Model Engine Wiring diagrams for Fuel Pump and Fuel Pump Control module.
http://imgur.com/a/1i8W4

Remove the Electrical Plug from the Fuel Pump Control Module.
ON THE PLUG CONNECTOR
Jumper (hot wire) RB at Pin 10 to GY at pin 7
Jumper (hot wire) GR at Pin 6 to B at pin 5.

This will drive the fuel pump directly from the Fuel Pump Relay and bypass the Fuel Pump Controller.

If the pump still does not work then it is the pump. Replace it.
Cheers!

(Reference http://legacygt.com/forums/showthread.p ... 13570.html)

Ok so problem is solved. Thanks everyone for your help diagnosing.

It turns out there was a bad connection inside the pump module. Where the blue and black wires (power and earth) connect to the housing in the back of the main plug there was heaps of resistance. Fixed it up, put back in and it is happy as a pig in poo!

Which explains why when I pulled the module out to replace the fuel pump, stripped down, replaced pump and reinstalled it all, it worked again briefly.
Similar but no the same problem as liberty wagon had.

Liberty Wagon wrote:I had this same problem with my 2005 Liberty.
My problem ended up being the fuel pump housing side of the plug. The little positive terminal had completly eroded and was stuck in the plug of the vehicle loom.
It can be hard to figure out if you don't know what you are looking for. Sounds like you may have a similar problem as when you push the plug in, it may be reconnecting the terminal to the housing temporarily.
I ended up purchasing a new housing and flicked the little terminal out of the plug and gave it a really good clean with contact cleaner.
No problems ever since.