Here is a follow up on my attempts to get the engine to run perfectly as I
awaken it from its 15+ year hibernation.
I checked the compression and each cylinder is 182. No variation at all.
That is better than I ever saw before. I had to buy a new tester since my old
one no longer works. Probably the new one is better than my old one was even
15+ years ago!
I checked the valve clearances and they were all in the 10-11 thou range One
was a little tight and I loosened it. One was a little loose and I tightened
it. I could tell that there had been one loose, by the sound at idle. With
the timing light, the louder click of the loose rocker seemed to synchronize
exactly with #1 firing, so I suspected that it was the #4 exhaust. The loose
one WAS that one!
I then used the Colortunes (on #1 and #4 cylinder). They look yellow to me.
That is supposed to mean rich. (When I removed the plugs, they were slightly
sooty, with a golden color just at the tip of the hook-shaped electrode, so I
thought the engine was running a little rich, maybe). I then tried to
lean-out the carbs, and I could lean it out to the point it would misfire, but
the color always looked yellow.
I tried to gun the engine and the yellow stayed when revving up, but would
briefly go blue (blue = good mixture, right?) as it revved down, then went
back yellow.
When I checked the lift of the carb pistons with those little wire doodads in
the SU tuning kit, the pistons seemed to lift more or less equally. Maybe the
front one lifted less, but it was hard to tell.
When I blocked off the PCV hose, the engine ran worse and the yellow color
persisted on the colortunes, again making me think that the yellow color is
really yellow, not the white on an ultra lean condition.
So what do you think is up here? Anything else to check?
Tony
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