I am stumped. I’ve had my mechanic work on this issue (the engine misses), and for the past few months thought the issue was resolved… Truck is 27 years old and has only 75K actual miles. Here’s what I have done.
Installed rebuilt carburetor - 2009
New plugs, wires, distributor cap and rotor - 2010
Adjusted carburetor, timing, and choke - Feb 2012
I normally drive it every couple days, yet during last winter it set up for a couple weeks with 10% ethanol fuel. In early spring, the engine started missing while driving (about 1/3 of the time). After taking to the shop a couple times, my mechanic basically gave up. I believe it’s time for a new mechanic. I may also give up and just get a newer truck, but not quite ready yet.
I suspected water in the tank, knowing that ethanol can attract moisture, so i ran the tank dry then bought 5 gallons ethanol free fuel (i live in the country where we can still find it). Engine started, ran great for a few months, and i thought i had solved the problem…until yesterday, when the engine started doing the same thing again just as it did when the problem originally started.
I would like to have some thoughts before I take it to another mechanic, so please send them my way