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

Three possibilities:

1) Once had similar on our 1985 CVH and it was the winding on the “rotor arm” in the distributor - our had the Bosch distributor.

2) Ignition amplifier faults will give the same symptoms. On our CVH, it was fixed to the side of the distributor.

3). A friend had something similar with an MG Midget which turned out to be a rubber fuel pipe breaking down internally. Looked fine from the outside.

As the condensor is mentioned here a couple of times:

As Paul writes it is mounted to the distributor. The part number for the distributor is Ford 81SF 12100 BAA (at least on the 1984 model - the 3 letters might be different on yours)
Checking a condensor is typically done by measuring the resistance. I know how to do this older distributors where it can be removed - I wouldn't know how to do this on the Ford 81SF 12100 BAA

I also don't know when Ford/Morgan changed the distributor and the cabling from two wires to a 3 pin connector. There is a repair kit and it has the newer connector. Check on your car on how the distributor is connected to the coil.

Instead of the repair kit, it might be a better idea to replace the entire distributor. I got this one here: Ultra Automotive

The replacement unit has also as the 3 pin connector. Ford offered a cable for earlier XR3 that needed a new distributor:
Part number Ford 84AG-12045-BA. This has the new 3 pin connector and a new one it is extremely hard to find.

Nevertheless - the venting issue that TBM notes, checking and cleaning the jets and AutoChoke should be done as well.

Regards
Tim

If no joy…….. do you have two switches activated by the brake pedal?

What condition are your plug leads? Age plus the heat coming up from the exhaust manifold can cause them to deteriorate.i had a misfire/ rev problem on an Escort and new leads solved it. Mine was an efi cvh engine. I bought standard new leads and not expensive up market ones.
Remember to change leads one at a time to make sure they are in the correct firing order!

I would suggest that you perform a compression test on each cylinder, as well as verifying if the timing is correct. You may also remove the timing belt cover (two bolts) and check the timing belt condition and its tension. Finally, I would also check the vacuum with a vacuum gauge.

... Oups!, I would have a look at the sparkplug, clean, check the gap and replace if necessary.

I'd also pop a new condensor in first and possibly a new rotor arm as well - the symptoms described of course could be something more involved, but sounds like a classic case of failing ignition components to me.

From the OP's original post.


There is always the possibility that one or more parts that have been replaced could show similar fault, however, it would be rather a coincidence for the symptoms to remain exactly the same.

Thanks everyone for the insights and suggestions. Plenty to work on. I’ll prioritise and work through them.

Just to close out the issue: I had the Weber carburettor stripped, cleaned, rebuilt and tuned on car. Apart from cumulative dirt/grime etc we found the only obvious thing was the float was out of correct calibration. The fuel hose from the pump to carburettor was also replaced. Fuel pressure checked OK as did the vacuum. Took the car for a 300km drive on some windy hilly roads last weekend and it didn’t miss a beat! 🤞