Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Breakdown

First true mechanical (I believe) breakdown, just past 4000 miles. Driving this evening and heard a bit of a clunk behind me and noticed that the accelerator no longer initiated any acceleration. Red oil light indicator came on. In the rush to get into the right lane safely so I could get off the road without getting hit, some of this is a blur. But I believe the engine was still running at idle when I came to a stop. I shut off the engine, but seem to believe it was, again, still running at idle at that point. Tried ignition and it would turn over but not start. Tried inertia switch, no avail. Drive belt is fine, fuses are fine. Then I noticed that when I would turn the key, I no longer heard that distinct sound from behind me.
Fuel pump? That’s my current most-likely hypothesis. The fuse for the pump is OK, and the wiring at the pump itself is intact. Spark plug wires are all connected. Drive belt is fine and no leaking fluids. Just a bit surprised it was still idling, but maybe it was just coughing. Will call dealer tomorrow.

Lets hope it is only a he fuel pump. 👍

Reset the fuel cutoff inertia switch just behind the oil tank. Hopefully nothing more serious. Good luck!

Oops, just re-read your post and see that you've tried resetting the inertia switch already. Definitely worth investigating the fuel pump. I presume the throttle cable is still connected?

Trust you're back on the road soon.

I am not really familiar with the M3W but most 4 wheel trads have a fuel pump relay, so even if the fuse is OK it could be the relay.

Having said that it is most unusual for a relay to fail while running, they normally expire after a long period of not being used.

It does sound like a fuel delivery system issue , good luck in tracing the root cause.

The fuel pump shouldn't go out with a clunk, at least mine didn't. Unless it fell off...
An idling engine also contradicts that theory. Not impossible, though. Does it start with external starting gas? Can you measure the fuel pressure?

The last time my M3W stopped with a clunk it was a snapped cam belt. The time before that it was the original compensator that disintegrated.

Is the drive belt ok?

Do let us know how it works out. Good luck!

It does sound like the fuel pump. The 'clunk' could be anything else as that rear can be quite vocal.

If it is the pump then replacing it is relatively straightforward. Then make a note that only ethanol free high octane fuel is to be used for ever after...

Michael, I too think the “clunk” (which in retrospect may have been more of a “feel” of the rear responding to the sudden loss of throttle) was just inertial and not the actual problem.
This morning, after letting her cool down, I hit the inertia switch again, and tried the ignition. The fuel pump had life but sounded like more of a low growl than the usual higher-pitched buzz. The engine caught for 3 or 4 seconds and then died. Repeated tries just resulted in shorter successes, so I do think it is the fuel pump dying. Will get towed to the dealer (still under warranty) in a couple of days. Have read about other pump failures. Wish there was a more robust substitute!
Also Michael, I have seen your warnings about ethanol in the past, but it is damn hard to find gasoline without it here in my area. The stations are few and far between.

https://www.pure-gas.org/index.jsp?stateprov=IL

This may help. There are far more out there than you might believe. Everything that uses small engines pretty much require it.