Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Engine faltering at 4k rpm

Hi All

I'm currently at work having commuted with the Mog this morning. It's been standing unused for the last three weeks, and I have a problem in that it seems to "stumble" at about 4k rpm. At first I thought I was just hitting the rev limiter... but it's more than that (and the rev limit is higher than 4k anyway).

Just been to fill up with fuel as it was empty, but it didn't make any difference. If anything it feels a bit worse, the stumble almost felt like kanagrooing when in seond gear.

Any ideas (apart from having breakdown assistance on speed dial) before I hit the evening traffic to go home?

Check the plugs & wires

Thanks Q8

Plug wires were on, but the ends of the plugs themselves were loose... have tightened them by hand, dont know if it could be that. Will see later...

After every 2hr drive,i have to use pliars to tighten the spark plug caps

I had the same symptom when my fuel pump was going out. The first instance of it happening was several seconds of on again, off again power and then it cleaned up and was fine for several hundred miles. It then quit completely and I flat bedded it home. After 24 hours, it worked again but I had an engine check light and only 23 psi at the check port on the right hand injector. I am waiting for a replacement at the moment.

Well there was no improvement on the way home, but it didn't worsen either. Still a definite problem above about 4100 rpm. Even revving the engine when the car is out of gear, the revs will only go to about 4.5, not higher. But at least I didn't end up on a flatbed.

Idle also sounds a bit different, but that could just be paranoia...

Will have to lay the car up until I can get it to my dealer, which will be 2 or 3 weeks at the earliest I guess (by which time the problem will almost certainly have vanished )

I had a similar problem earlier this summer at 2500 miles, changed both spark plugs for NGK ones, problem disappeared.

It's a simple motor and doesn't take much to throw it off. The threaded nipple attached to the spark plug on one of the cylinders had either fallen off or been missing since forever. Motor ran ok but it idled badly and it was very ragged at high revs.

Damn lead fell off and when I looked at why I realized that there was not much holding the lead there! Replaced the plugs and made sure that the gaps were right and it is a new motor!

Update: my ECU had corrupted (or whatever the correct term is) and was limiting the revs to 4k. New ECU on the way from the UK. Luckily still under warranty (just).

Lucky guy!