Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Plus 4 (2005) Fuel Pump Issue

The following may be of interest:
Had been out for a run. Stopped car on driveway and engine wouldn’t restart. No sound from fuel pump energising when I turned the ignition key so I knew it was a pump issue. Replaced fuel pump relay to no avail. Removed spare wheel and gubbins to get to fuel pump live feed. Removed 6 pin plug from fuel pump and confirmed live feed OK. Took advice from Spanner Juggler who suggested I try impact engineering as the commutator in the pump may have stuck. Belted the top of the pump with a hammer. Refitted the plug to the pump, turned on ignition and pump energised and engine started.

This was the state of the plug socket:



I removed the plug to clean the crap out of the socket but found when I replaced it the engine wouldn’t start. Clearly impact engineering hadn’t solved the problem in this instance.

This was the state of the plug:






Closer inspection revealed that the white/purple (live feed to pump) wire had split, the plug surrounding the female live pin had melted and the female pin had opened up. After tweaking the pin and reconnecting the plug the engine started.

As the local auto electrician was unable to source a new plug, I followed Spanner Juggler’s recommendation and cut off the plug and wired direct to the male pins on the pump using soldered connections.

This may only have become an issue on my car owing to its relatively high mileage, but something to watch out for.

As an aside, I mentioned this to Rog when I gave him feedback on the spring assisters he had supplied and he provided a link to a replacement plug.

Nice find Ken.

So a hypothetical question to all the electrical experts out there re the fuel pump connector over heating.

The connector terminals only appears to be rated to 12 amps but I think Morgan use a 30 amp fuel pump fuse. Would say an inline 10A fuse be beneficial should a fault develop in the motor (like the windings breaking down) causing extra current draw? At least It might prevent difficult to find random failures of other components, or even worse!

In this world of risk management and cutting costs being prioritised ever more to maintain margins, it seems quality is that which suffers while our expectations of it seem to ever rise...?

In very general terms and as best I understand it.... It takes circa seven times the amount of current to start an electric motor than it takes for it to run happily, which as you might imagine makes deciding the correct fuse and wiring and connector size a bit of a conundrum...? For sure the high current peak is very short lived before the pump is up to normal operating speed and the current demand drops accordingly. The hope would tend to be that whoever worked out the fuse type/rating, did so in the full knowledge of ALL the components in the circuit being specified for the task they were selected to perform, and up to the job. Of course the passage of time, lack of maintenance and misuse can alter much..

Also if you then add the environment in which all of the kit is expected to operate, there are even more complexities to consider... it does not take too much for an electrical connection to fail. In general the easier it is to make, the easier is for it to break, and push fit is about as easy a method to make a connection as one can get..?

Just thinking in type, no expertise claimed.