well, ran into a snag tonight and sat on the side of the road for about 45 minutes. now i'm home and a bit befuddled.
i previously yanked the engine (1600dp upright in a '76 camper bus) and replaced the heads, all clutch components, rear main seal, cam plug, tranny shaft seal, air cleaner, intake, exhaust, alternator, distributor (acn svda with compufire), plugs and wires. i replaced the braided fuel lines and moved the fuel filter under the tank. lotsa other small stuff, too.
spent the entire afternoon/evening getting everything working; sounded/felt/acted great. to test went about 6 miles via country roads, two exits down the highway. got on the highway to come back at higher speed, did great for a few miles and felt the engine miss. then again. then backfire, and the engine was dead. couldn't start it by popping the clutch while coasting. turned over fine, just didn't fire.
turned on the blinkers, got out the flashlight. checked the wires. checked the fuel line. checked for leaks underneath. popped the distributor cap - the rotor wasn't free (didn't pop outta gear), all contacts still looked brand new. the distributor wouldn't turn, so timing hadn't drifted. no funny smells other than the new exhaust baking. got back in, started right up. ???
drover about a mile. same thing happened again, minus the backfire, within
100 yards of my exit. less than 2 miles from the house. rechecked some of the original stuff, crawled underneath and found gas in the filter. waited 10 minutes and hit the switch, no go. crank but no fire. figured it must be electrical - possibly the (new) coil, (new) distributor, or (new) magnetic points replacement. called the wife to bring me the old distributor, an extra flashlight, and a gatorade. why it restarted once before kinda baffled me.wife showed up, i put her in the front seat to hit the switch so that i could yank the coil wire and check for spark. i ran her through the steps (she's very much an automatic minivan-type person) and when she hit the switch for practice it started right up. she didn't even give it gas - it just started up and idled perfectly. kissed her, kicked her out and got on the road asap hoping to make it home before it quit again. thankfully, i did.
so now i'm thinking it's either heat related or possibly fuel starvation. i have an oil temp dipstick sending unit, and know the engine wasn't overly hot. but i've had a fuel pump go out on me with almost identical symptoms on my 73 super. the bus has an engine from a 74 super. i surmise that possibly the pump got hot and couldn't keep the fuel going; either gas gravity-fed back toward the engine while stopped, or the fuel pump cooled off enough to work and get me home. either of those make any sense? anything else i should be looking at?
supposed to go camping first thing in the morning - guess i'll have to miss BOTHER (Buses On THE River) this year. krikey.
the good news, at least as far a i can tell ... the acn svda seemed to definitely give more pep than previously; i could tell a big difference at lower rpms (no hesitation at all) and the new clutch certainly grabs better than the one it replaced. i'm looking forward to getting a better feel for the svda distributor - the bus is quite underpowered with the little 1600 but it feels like a whole different bus now that it actually goes when i hit the gas.
i called the mechanic, who will be on his way to my place tomorrow morning. if we can positively id and fix the problem, i plan to take off for BOTHER. if the situation is iffy at all, i'm staying home and will probably work instead. and that will suck, of course.