I posted something about this in other threads, but the problem persists so I figure best to start anew.
The engine is a 1.9, low compression. I assembled it and ran it on a test stand last summer. It ran great. I put it under a tarp until last week when it was time to put it in a car. I opened it up to check for rust and everything was good. Just a few spots on the valve cover.
So now it is in the car and I am having a devil of a time getting it to run. Initially it would start and would rev up to 2000-2500 rpm, then die, on starter fluid. Later I tried dribbling gas in and I got the same result. First suspect, fuel, so I drained the fuel lines and ran a hose to a gas can. No improvement. I removed and reinspected the carburetor (32/36). No change.
The crazy revving suggested a vacuum leak so I plugged the vacuum advance ports. After that I was able to start the car without starter fluid or a dribble of gas, but it would backfire (out the carb) like crazy, and would not idle.
I double and triple-checked the firing order. 1-3-4-2.
Sticking valve? I removed the valve cover. All valves go up and down. I ran compression tests (cold) and got 140 +/- on all four.
One by one I removed a spark plug wire and cranked, and the symptoms did not change. I was hoping that for some reason one cylinder was causing these problems. Nope. All of them do it.
This sounds like a timing issue. I verified ignition timing: needle on the ball, mark on the crank pulley, rotor pointing to 4 o'clock, rockers for #1 loose. I cranked it around and checked cam timing. Again, needle on the ball, mark on the crank pulley, rotor pointing to 10 o'clock. The dowel pin was at the top and using a metal ruler I could draw a straight line between the center of the cam, the mark on the cam sprocket, and the notch on the little hickey under the cam sprocket. Cam timing is good.
If I advance the ignition 20-30 degrees the car will start and not backfire, but it runs rough and won't idle.
Other than pulling the distributor and checking it out, which I will do after lunch, I am out of ideas.