After 4 days on the road, it feels l weird to more or less just stay at one place for the next two weeks. But it gave me time to think and investigate the possible Vapor-lock problem that might cause the power-loss issues. Cleaning and some technical checks were planned anyway.
Vapor-lock can have a number of causes. I already check a number of possible causes. Here is a list of what I (more or less) rule out:
- Fuel line clogging issues
- Fuel lines that get very hot or touch the engine
- Fuel filter issues
- Fuel pressure or fuel pump issues
- Fuel tank venting issues
- wrong fuel (eg. E10 – Ethanol based fuel)
- Carburetor jetting issues (eg. dirt)
It is difficult to find the common-denominator for this issue. It surely has to do with temperature. What is strange is that the the underhood tempetures do not seem to be extreme. I remember opening the hood of the Morgan in the past with much more hot air coming out. What I do know is that stop-and-go traffic as well as the hot summer here contribute to the problem. High altitudes were also not favorable as we experience on the Timmelsjoch ascent.
Vapor-lock means that fuel is getting too hot and evaporates before it gets through the jets of the carb. The inlet manifold on the Morgan is connected to the coolant systems. As far as I know this is has to do with emission control regulations. The Weber 32/34 DFT is mounted on top. I decided to check the pictures from the disassambly and found one difference/mistake. The old insulator block was mounted above the heat-shield. On reassembly I put the new one I ordered underneath the shield. I also remember that the new insulator has only 2/3 third of the thickness. This is something I can easily change here on my trip and 10 min later – the change was completed.
I also checked all screws on the front suspension and steering. The down lower screws of the steering box were not as tight as I wanted them. Tightening them makes are remarkable difference in the steering accuracy. Another important change was to increase the front dampers to maximum setting. On the AVO shocks I can adjust the setting from lowest to highest setting with 16 clicks. I set front dampers to 15 clicks. A first test drive on the rough roads here felt much better.
It will be interesting to see if the changes solved to the problem. I think the root cause might be really within the cooling system. An air bubble in the coolant system after 6000km? Somewhat unlikely. Back home I will certainly improve the carb-heatshield – but my gutt-feeling is that this is not the root cause.
Fixing C6622 
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