Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Fuel Supply issues

Good morning wise ones. When I try to start my car, 1998 Plus 4 Rover T16, from cold there is no fuel flow. I used to wiggle what I thought was the relay for the fuel pump in a unit by the coil pack and then it worked. Then it didn’t. So I found what I now think may be the fuel pump relay behind the dash. It worked for a while. Now it doesn’t. I have a gadget on the bulkhead, engine side, which I believe cuts off the fuel pump after an accident, if I press the button to reset this gadget, I have fuel. After a run I have no problem, and she never misses a beat whilst driving. On the subject, I bought a replacement fuel pump relay from MR to keep with my spares and it fits nothing I can find on the car. I would post pictures but I don’t know how, yet. Help gratefully accepted as always.
Thanks

If the fuel cut off switch needs resetting I would check the connectors to it for corrosion. It should only work on impact & might be faulty or have poor connections. Brands Hatch Morgans should be able to help you on the relay.

Not to be driven .... but for a cold start test, can you jumper out the cut out switch to eliminate it from your search?

K

Sorry I have no idea of the set-up on your Morgan, though if jiggling a relay to get it going has been a habit, and if the base of the relay is fixed when you were jiggling the relay it`s self, perhaps you were disturbing corroded or burned connections between the base and the relay, and thus remade some sort of temporary connectivity between the relay and it`s base... Pulling the relay and looking at the connections might provide a hint as to whether the points of connection may be the issue..?

The fuel pump draws a fair bit of current and in time the contacts within the relay can burn to the extent that the relay fails to bring the pump on.

The reset you describe seems likely to be an inertia switch which is designed to shut the fuel off after a shunt, though I have heard tales of a re-set being required after hitting a deep pot hole..

All switches and relays can be by passed with a link wire (jumper) to help diagnose where the problem lies.

A wiring diagram might help improve understanding, however it seems wiring systems on Morgans can vary even within the same year/model range. and if you have any immobiliser circuitry involved, it may also have a hand in disabling the fuel pump..?

www.GoMoG.com is another possible source of further information perhaps worth looking at..?

Good luck..

Hi, thanks for the replies so far. I am mainly concerned that the, fix, is moving around the car. The problem is constant in that the fuel pump seems to be stalled until I jiggle some wiring but what worked at first now doesn’t. It may be that there is simply a bad earth somewhere but I have no idea where to start and don’t want to pay a local, French auto electrician while he learns about Moggie wiring.

Graham, sorry to say that if you do not wish to pay to have your Morgan repaired then it is down to YOU to learn how to DIY, just as many of us have done over the years... As for waggling wires to get it to work, in such a situation, you could be disturbing a poor connection as suggested, or it may have no linkage whatsoever if the fault which could be intermittently resolving it`s self, thus you might as well say a prayer to St Malvern to see if that makes it work..?

Yeah checking earths is a reasonable starting point and usually one of the weak points in a system on an older car that may have been used in all weathers. Basic electrical circuitry is simple to learn enough to understand the various points of contact in order for the circuit to operate as it should though as soon as digital electronics plays a part the game changes.

Ideally someone on here who knows your type of Mog and it`s systems can inform you where the relay is positioned and other possible failure points in the circuit where you can make tests, other than that it is down to you to educate yourself, with a bit of back-up from the TM team..

Good luck..

Common item is the fuel pump itself Graham so I would look there first. Thoughts are that by moving wiring about you are interrupting power momentarily and that alone pulls the lazy pump into life.

Try first disconnecting pump wiring then applying direct feed of 12 volts and check it always runs.

GoMog as a website has a lot of useful info. This is where the earths are on a later Roadster but I expect your car to be similar.
Some fuel pumps have separate earths.

"Here are the major grounding points on the Morgan Roadster (USA). These may be identical, similar or not at all like the ground on the late model +8s of the same vintage or the other world versions.



1. Behind the Fascia there is a ground terminal on the heater box. Suggest moving this to the scuttle bar.


2. Engine had a ground strap to the scuttle (firewall).


3. Engine computer, inside the fuse box, a wire runs to a bolt on the bottom of the fuse box.


4. Outside of right hand valence (remove the right front wheel) near the air intake tube.


5. On the rear chassis member near the right rear wheel.


6. And of course, the chassis to battery ground. "