Stuck out with no fuel pump

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spiderwheels · #1 Post by **spiderwheels** » Tue Sep 27, 2016 5:35 pm

I think a connector may have dropped off. Anyone know which is the most likely culprit and can you get to it with the toolkit?

Dalemac · #2 Post by **Dalemac** » Tue Sep 27, 2016 9:29 pm

I think the fuel pump connector is buried down the back of the battery and ECU area.

Seat/pod off, battery out and then ECU out.

#3 Post by **mangocrazy** » Wed Sep 28, 2016 9:18 am

Not sure it's quite that drastic, Dale. Seat off, definitely, but then find the lead originating from the fuel pump at the back of the tank and trace it to the white/cream connector. Its normally stuffed under the tank, in front of the battery or routed round the side of the battery with other cabling, from memory.

spiderwheels · #4 Post by **spiderwheels** » Wed Sep 28, 2016 9:46 am

Thanks guys.

As it happens I was home well before 9:30 pm.

I sat in the nearby hotel bar for an hour and then tried it again on the off chance.

I still didn't hear the fuel pump prime but it fired up anyway and I rode home before it changed it's mind.

Probably a bad earth.

Falcopops · #5 Post by **Falcopops** » Wed Sep 28, 2016 10:49 am

have a wiggle of the wires next time you get a chance and see if there's a dodgy wire. There have been cases of the wires breaking in the potting compound where they pass into the tank through the tank base

fatboy · #6 Post by **fatboy** » Wed Sep 28, 2016 6:31 pm

Been there, done that...
Fuel pump would cut out when it got warm, fire up again as soon as it cooled, major headfuck as I knew it was a fuel supply problem, every time I bench tested the pump it worked because I was providing an independant earth, wire it back into the loom and earth failure...
Griff told me I never would have worked this out without a plug in.
You will find the spur from the loom to the pump on the LHS near the relays under tail unit.
Try a resistance test on the in tank wiring, if you get varying readings then you more than likely need a new pump

spiderwheels · #7 Post by **spiderwheels** » Thu Sep 29, 2016 5:30 pm

fatboy wrote:Been there, done that...
Fuel pump would cut out when it got warm, fire up again as soon as it cooled, major headfuck as I knew it was a fuel supply problem, every time I bench tested the pump it worked because I was providing an independant earth, wire it back into the loom and earth failure...

Did it cut out on the move or just failing to start when warm?

fatboy · #8 Post by **fatboy** » Thu Sep 29, 2016 6:30 pm

I will try and give you as much detail as I can,
Griff found the pump to be at fault in a diagnostic test. it would prime and fire up from cold but the pump would cut out when running and warm. I bodged this by running an independant earth to the pump but this caused the low fuel light to be on all the time, Griff advised this would not do the sensitive dash display any favours.
If you can't hear the fuel pump prime when the ECU boots up then there could be other issues such as pump relay, engine shut off relay,interlock diode or even ECU itself.
Let us know how you go....
Classic sign of fuel pump failure is cutting out when it gets warm and the earth breaks down.
Time to look at a wiring diagram, good luck

spiderwheels · #9 Post by **spiderwheels** » Thu Sep 29, 2016 7:37 pm

Thanks for the detail.

It didn't cut out on me while running. I'd parked up for 20 minutes.

When I was trying to restart it the low fuel light came on while the starter was running and went out again when I let it off.

After an hour it was fine and didn't misbehave on the ride home. I haven't gone out on it since but the pump is priming each time the key is turned and it is starting quite happily. I'll have to take a ride not too far from home and see what happens.

fatboy · #10 Post by **fatboy** » Fri Sep 30, 2016 6:18 pm

If the pump primes then it would seem that the ECU and relevant relays work.
If you have a multi meter then do a resistance test on the pump when disconnected from the loom, long flat 3 pin block connector with green/black,orange/black,blue from the main loom, near all the relays LHS,
Sorry,cant really quantify how long it would run before conking out....
180 miles back from Cornwall/ 2 miles to shop and anything in between.
Good luck with finding the gremlins

Wally · #11 Post by **Wally** » Wed Oct 26, 2016 9:31 pm

I was stranded the other day when all power was lost and I had to freewheel to a stop.

Fuel pump was not running or priming, so i tested the earth and live to the connector to the fuel pump and all was OK. Removed fuel tank and then fuel pump to find a break in the wire where it enters the bottom of the pump mounting plate.

Has anybody done a repair to one of these wires? How do you re-seal around the wire? What is under "what looks like araldite" where the wires go thru to the tank?

Any help appreciated

Wally

flatlander · #12 Post by **flatlander** » Thu Oct 27, 2016 9:34 am

Personally I would look at replacing it rather than repairing it

fatboy · #13 Post by **fatboy** » Thu Oct 27, 2016 3:52 pm

It is possible to buy the spur that comes off the loom with the 3 skinny little wires that connects to the pump...not cheap.
Got one from AP few years ago, just under £40 minus vat.
Maybe look for s/hand pump with wiring as your chances of repairing a wire that small are well as slim as the wire itself

Wally · #14 Post by **Wally** » Thu Oct 27, 2016 10:45 pm

Thanks for the advice, I'll just have to use the XJR until it's sorted (not as much fun though)

Wally

DavShill · #15 Post by **DavShill** » Sun Oct 30, 2016 1:53 pm

Ive got a spare fuel pump. You can it for what I paid. I tested it when it arrived and all worked fine. £75 including postage.
PM me if you still need one.