Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Morgan 3 wheeler Check engine light !

Hmmm quick research comes up with fuel octane rating, plugs and leads as possible causes as well as carbon build up in the cylinder.

Usually this fault code is because of a failing fuel pump. The supply pressure is reduced and the ECU compensates by extending the injection pulse until it reaches it's limit. Have you replaced your original standard fuel pump with a Walbro item as in these detailed instructions Malcolm M3W? https://www.mtwc.co.uk/wp-content/u...-pump-replacement-April-2020-update.pdf. If not I would suggest it is a good starting point as it will fail at some point in the not too distant future anyway. The original item is very unreliable. It is such a common replacement that Glenco Ltd. now produce a kit of parts for the M3W p/n ITP184.

You could check the fuel pressure at the test point on the RH injector, if it is less than 58 psi then this will confirm the problem is the fuel pump. Following the fuel pump replacement, it is a good idea to reset the adaptive maps using ProTune 2 as they will be compromised by the low fuel delivery pressure. You can only enter Advanced mode if you have an unlocked ECU but you should be able to reset the adaptive maps by disconnecting the battery for a few minutes if you cannot access it in Basic mode with a locked ECU. The front cylinder is the LH (Port) one, or RH if you are looking at it stood in front.

this one, Ian? and with this kit you still need to make the mods suggested in your instructions, correct?

https://www.glencoeltd.co.uk/morgan-m3w-fuel-pump-upgrade-kit-ti-automotive-walbro/

Yes, but Glencoe no longer export to the USA, if you call Cath at Advance Automotives +044 1179 672344 she will ship the kit.

That is correct but you may be able to find a more local supplier in the USA, Summit Racing Kit 400-766 has been suggested but you will have to check the contents match up.

Re the check engine lights - had you recently filled up with petrol? If you "overfill" the tank it can trigger the check light which should eventually disappear on it's own.


I put "overfill" in parenthesis as the trick is to fill slowly as you get near to full and stop after no more than 3 slicks of the pump auto shutoff. If you go beyond this there's a range of symptoms including difficulty in starting, rough running, cutting out and the check engine light.

Thanks for all the tips, much appreciated. I will work my way throught them soon and let you know the results.

There was a dry moment yesterday when I took the car out again, twice. The first run had the engine light on but the second time it didn't come on. Fuel levels were low in both cases. No idea which fuel pump i have at the moment and if there isn't an inbuilt fuel pressure sensor in the system then that will need some thought on how to measure too.

To test the fuel pressure you need something like this:

https://www.machinemart.co.uk/p/cla...VQqrEAQYAiABEgIw5fD_BwE&gclsrc=aw.ds

There is a test point, Schrader valve, on top of the engine.

I had this problem. Traced it to loose threaded alloy end caps on the spark plugs. The tiny sparks created confuse the ECU. I have found that they are hard to keep tight, but any time my light comes on I tighten them up and all is well. Causes rough running at low revs too.

Ditto on this. The screw-on nipples on most plugs will have a tendency to work loose with time. I remove them put on some Loctite and put them back on then crimp them HARD so they will not ever move. The warning lamp goes off and the engine runs smooth. Well, as smooth as a V-Twin ever gets!