Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) CVH engine sudden power loss

I’m trying to diagnose and fix a serious problem that has developed with my 1985 4/4 Roadster fitted with the Ford 1.6 litre CVH Engine. ( purchased in March this year with only 28,000 miles on the clock! I have clocked up 700 miles since then). Intermittent and sudden loss of power under load. Most disconcerting when you are entering a roundabout or overtaking! I have replaced all the ignition system components (all plug and distributor/coil leads, coil, rotor arm, spark plugs and distributor cap). All filters have been checked and replaced where necessary. The engine is fitted with a Facet electronic fuel pump (pressure tested OK) and Weber carburettor. On a run the engine can run well for hours, then the next time you go on a run it will happen without warning. I don’t think it is the timing and it only happens when the engine is hot and under load. When placed in neutral the engine will rev with some slight misfiring but when placed into gear the engine speed drops and stalls under load. Switching off and leaving for half an hour sometimes cures it or revving up to 4000 rpm and slipping the clutch will get some results, just enough to get you home. By process of elimination I can only assume it may be fuel related. I’d appreciate feedback from anyone who has had a similar problem and how it was fixed.

My son had a similar symptoms with his Ford Escort (1.6cvh) some years ago. That was a faulty catalytic convertor where the innards had got displaced and partly blocked the exhaust. It would only do about 35mph when hot. Any noise or rattles from the exhaust system apparent?

Try the distributor condenser, many of the imported copies are very poor quality & fail intermittently

I don't believe that a 1985 CVH Morgan had a catalytic converter yet. At least my 1984 does not have one.

With the low mileage and the description above I would also assume it is fuel related. A quick an easy check is the AutoChoke on the Weber 32/34 DFT. During my restoration I bought 3 old replacement units - all over them had a broken weight on the choke lever arm. This causes strange issues ...
I had a couple of blog posts on the Weber during my restoration. There is a picture with red arrow in the gallery of this post. Have a look.

Before you unscrew the 3 screws of the thermostat housing - use a punch or paint to mark the location. You want to install it back in the same location if the inside still looks ok.

The low mileage (and maybe the use of E10 fuel) could also mean the jets and carb need to be cleaned. Have a look at the Webcon facebook page When you remove the jets - make sure to remember the correct location for the primary and secondary jets.
Contact Juan in the UK (from the youtube channel Air Fuel Mixologist) if you don't want to do a carb cleanup/rebuild yourself.

Even though I spent money and time on the Weber 32/34 DFT - I still consider replacing it with a 32/34 DMTL. Despite comments and recommendations here in the forum for a Weber 32/36 DGV - Webcon told me:
..." 32/36 DGV is designed to suit the Pinto and the DMTL is designed to suit the CVH, be it Transverse in the XR3 or longitudinal in the Morgan. "

Hope this helps somehow
Regards
Tim

I'd check the coil with some freeze spray (or substitution) if you have any, quite common to break down with high temperature.

This video also helped me. He explains flooding and vapor lock issues quite well: [video:youtube]https://www.youtube.com/watch?v=XPrYK6bcctc[/video]

I'd try condenser first too....

And, if it has one, the ignition amplifier (can't remember what year they were introduced on the CVH, but can suffer breakdown if they get too hot).
Also check the wiring connections to the fuel pump - had that problem on my early Zetec - an occasional loose contact.

Is your fuel cap venting OK? Could be a vacuum build up in the tank. Next time it happens, remove the fuel cap - if you get a large 'whoosh' that suggests a vent issue.

I had an issue with blocking idle jets - but that just affected tickover/idle I replaced the standard filter with a high spec cleanable one and it cured it.

I had some intermttent running on the way back from Wales last week - similar symptoms to yours. It was a blocked filter. At some point I think a previous owner has coated the inside of the fuel tank. The ethanol is slowly stripping it off - filter was filled with silver paint strips.

I always carry a spare filter so can do a roadside swap if needed, and have a can of carb cleaner under the seat for unblocking jets!

+1