Problems with the engine

[mech0001]

Pumps and vapor lock are always prime suspects when engines stumble and die, but hoses, connections and the fuel selector valve should also be verified.

When I first got the Birchaven I had a number of things that were additive in causing the problems. One was the fuel selector valve was sucking from both tanks at the same time. I don't know if it was an intermittent problem or persistent, but higher fuel levels masked the problem. When the fuel level was lower and I was taking a left turn the problem would rear its head.

Another problem was the rubber fuel line on top of the tanks was partially flattened so it was oval, when under suction it would flatten more and be more restrictive. When fuel hose, any hose, is wound onto the spool at the factory it's done under tension and the hose takes a set. Pinch a piece of fuel hose between your fingers then rotate the hose 90° and pinch it again. You'll feel the difference in the amount of force it takes to pinch the hose. I don't think that this is a major factor, more a contributing one.

After I had the valve and hoses replaced I discovered that a couple of the hose clamps hadn't been tightened. They were on the suction side of the selector valve and didn't leak fluid, but it's possible that air was able to enter the fuel stream and create a bubble. Again, maybe not likely, but another easy thing to check.

The above AND the fact fuel has become more and more aggressive towards rubber products. That was my reason for going with AN6 line as the internal hose is plastic and has a high pressure rating when used with its (usually) proprietary fittings.

 

[ScottC]

Did you put thermal compound (heat sink grease) on the back of the ignition module before installing?

The wires on the distributor pickup fatigue and break from the vacuum advance moving them back and forth continuously causing intermittent ignition.

My coach would stumble, die or not start intermittently. I finally found an OEM crimp connector that was fully crimped on the insulation but the conductor itself was loose in the connector. Once I found that and re-crimped the wire tight it has run great ever since!

Just had a similar issue that had us on side of road but I knew it was ignition, assumption was module, coil or pick-ups, turned out it was the power wire to HEI, when the PO converted from points a new connection was made and failed. Check that power wire, I had to wiggle it pretty good to recreate the power failure.

 

[LQQKatJon]

Just had a similar issue that had us on side of road but I knew it was ignition, assumption was module, coil or pick-ups, turned out it was the power wire to HEI, when the PO converted from points a new connection was made and failed. Check that power wire, I had to wiggle it pretty good to recreate the power failure.

One reason I would hook up a timing light. Zip tie the trigger on and set it where you can see a flash as you drive. When it is stalling out watch that light. Can show if you are loosing spark.

some dire cases, put a test light on that wire going to distributor. See if your loosing power at all. .