75 FI Bus Engine Misses- Need Help

[Amskeptic]

I am pretty sure that the problem is solved (I hope it doesn't come back now that I write about it).

Since I bought the bus, I had always set the timing wrong.
Mr. Muir says to set the timing statically, and that is what I did. 5 degrees ATDC. Now, if I check with the timing light, it is way off, way retarded. Like 12 degrees off. Since I set it with a light, the hiccups seem to be gone. It can be so easy....

Stony

Now Stony.
A) Congratulations on solving the problem.
B) Mr. Muir cannot have said to time a F.I. engine statically or I'll eat my 10mm wrench (he better not have).
C) For future reference: any AFTER Top Dead Center timing specification is relying on a vacuum retard unit that is functioning, which requires a running engine.
The 12* you speak of is exactly the error range of statically timing an engine with a vacuum retard, because the timing does skip up to 7.5 BTDC when you pull the vacuum retard hose off!
Colin
(p.s. I ran my engine that way for almost the entire first year I owned the Road Warrior because I did not check to see if my vacuum retard was working)

[stony]

I am back again. We made it from San Francisco to Baja California without any problems. Now, every once in a while those hiccups come again. Like once or twice a day, some days never. This time the timing is perfect.
Can it have anything to do with a hot engine, which I don't really think that I have?

[stony]

For the last few days we had these problems again and again. Sometimes they lasted 5 or 6 seconds. The engine would run, but hitting the gas pedal wouldn't change a thing, as if no gas would reach the engine. I will change the fuel filter again tonight (I have been driving lots of dirt roads here in Mexico) and check the electric supply to the pump.
Muir says to change the timing one degree for every 1000 feet above 4000 feet above see level. That would change my timing 2 or 3 degrees here at this altitude. Does that apply to fuel injection?