Does this sound like a clogged idle jet?

[CBA]

Hi Christian. I've checked most of the things you mentioned. There were no HT leaks after running it in the dark. The vacuum line from the carb to the distributor is metal, but I removed it and blew through it, it appears clear. I checked for gasket leaks by spraying carb cleaner along the edges of the inlet manifold on the head and below the carb; I thought I would see it sucked dry immediately if it was drawn into a leak, but they appear tight.

One new breakthrough though. Instead of running the car for a few seconds and letting it die, I persisted in feathering the throttle as I racked my brains on the problem. Over six to eight minutes the RPMs very gradually increased. As the RPMs increased, the engine gradually smoothed out. Suddenly, it revved up nicely (sorry I don't have a tach to give a proper readout) and ran beautifully. I gradually let the engine return to idle; after dropping smoothly a bit, it ran rough as before and died almost immediately.

A co-worker who builds hot rods thinks this may be due to a faulty vacuum advance; I really didn't understand the theory behind it, but thought I'd ask your opinion before I pursue it.

I'm also going to check the compression on your advice, but the person with the equipment isn't available until the weekend. So if you think the vacuum unit on the distributor is a reasonable possibility I'll work on it in the meantime. Thanks, Doug


What ya think?

[volvodspec]

yes,

let him clean the jet out and check the electric solenoid on it, should click if ignition is on.