No juice to fuel pump

[MissMoppet]

A fortnight ago I picked up my '74 Stag (+RV8) from a Midlands dealer and drove it home. For the past week I have been unable to start it. Eventually we have traced the fault to no current going into the fuel pump. If we place another spare battery in the boot and connect up it will start but it does rather take up a lot of room, and may possibly tip over on cornering . . . Rummaging around these Forums ("fuel starvation") suggested a suspected inertia switch but bypassing this does not cure it, so there must be a break in the wiring somewhere along the line. Nothing else has been touched. While we can't find which fuse manages the pump everything else seems to work - and we can start it from the spare battery.
Any ideas most gratefully received.

[KOY 23]

Welcome to Stag ownership. There is no fuse for the fuel pump, it gets it's feed from the ignition controlled relay via the inertia switch. If everything else works, the relay must be ok. You need to check the white feed wire to the inertia switch and white/light green through to the pump. Use a headlamp bulb instead of a voltmeter. Has any welding been done to the rear wheel arches as loom passes nearby and might have been cooked.

John.

[jleyton]

Where about's in Somerset are you ? - if you're near then I'd be happy to lend a hand if you need it.

Cheers

Julian

[milothedog]

Just a thought and seeing as the car has been re-engined, it may be possible that the fuel pump has been wired to only work on a running feed via the Alternator or oil pressure switch.

Probably not the case but if all else fails worth checking out.

Ian.

[Goldstar]

If it started OK when you picked it up then the fault is probably a break in the feed wire somewhere causing an intermittent fault as John mentions above the loom could have been 'mig'd'

Paul

[V Mad]

Have you got any volts at the pump, if so how much?

In my experience the SU pump can become lazy and will only work when the volts are sufficiently high (eg 12.5v or more). Typical voltage drop down the wires is up to a volt on load, so it could be your pump is weak.

[MB]

Does it have an alarm or security device by-passing the feed to the fuel pump? Any hidden switches cutting off the supply?

[MissMoppet]

There was one fitted but this has been (temporarily) disconnected.

[MissMoppet]

Solved. Got 11.8 v at the pump. Checked and changed several grotty spade connectors and now it fires up. Went for first run in a week - hood off, heater on - ah youth. Having met a tractor down a narrow lane - next question: how do you fit ABS?
Thanks chaps for all your advice.

[richardthestag]

good work, I have had many issues on my stag due to poor connections. 12v unloaded is no good if it don't light a bulb which is why I have a bulb and 2 crock clips to test anything ropey.


re tractors - backside off the seat and folding the steering wheel in half? did it lock any wheels? Not sure about retrofitting abs, suggest getting top notch brake bits fitted and the best tyres you can afford. My stag stops pretty quick but is nothing compared to the moderns. My Range Rover has ABS and that is a savoiur on the motorway and a PITA in the snow.

[jleyton]

MissMoppet, (can we call you anything different ?) Glad you got sorted.

I tried replying to your email but got this: "Sorry! That user has specified that they do not wish to receive emails" - don't know if that's deliberate or something in the system .

Cheers

Julian

[MissMoppet]

Yes the wheels locked - only doing 30mph - but boy do I miss my Mazda 6 when you need to stop. The PO spent £500 on new calipers and braided hoses in last 3 months. I've serach Forums for ABS but with no joy. Someone must have tried?

[DJT]

Speak to 4x4. He has one of the four-wheel-drive Stags and ISTR that it is fitted with the Dunlop Maxaret system.







Or am I talking b******s

[KOY 23]

Dave, for once.........no.

[jleyton]

Speak to 4x4. He has one of the four-wheel-drive Stags and ISTR that it is fitted with the Dunlop Maxaret system.
Or am I talking b******s

Somehow I think it would cost a bob or two to fit that to a Stag - unless anyone knows of a scrap Jensen FF anywhere

Cheers

Julian