COMET CENTRAL

Here's the story. 65 Comet with the 200-6, stock carb and dizzy. Car is new to me so im not sure how long this has been a problem. It runs pretty good when cold, but once ot gets hot, say above 180°, it will idle but stall immediately upon presding the throttle. If I pump the throttle, I can drive it as long as I keep pumping it. If i hold the throttle down, say halfway, it will rev up for a sec then back to idle, then immediately rev up again and back to idle. It will do this forever probably. I believe it is related to the carb getting too hot but not sure how to fix that if it is indeed the problem. Plugs, cap, rotor, points all new and set properly. Float height is set to spec.

well, I'll start (and this is just from the hip)...

In no particular order other than to avoid spending money until you have to:

If you have a vacuum advance on your dizzy, I'd disconnect that and plug the line.

Then I'd start looking for vacuum leaks around the carb or on any other line to the carb. Power brakes, check that vacuum line, PCV valve, check that line. Gasket under the carb or spacer, is it in good shape?

Throttle shaft? while at idle, move it by hand and see if the car stumbles right as you advance the accelerator.

While at idle, get a can of carb cleaner and spray around the carb looking for the leak.

Accelerator pump (leaking)?

Power valve (not sure if the I6 carb even has one of these)?

If you can't find any leaks or anything wrong with the Accelerator pump or power valve, then maybe the idle mixture screws?

Basically, it sounds carb related, but to me it sounds like your air fuel mixture goes whacky when you hit the accelerator (not a heat issue).

Does it have the plate under the carb that the water line hooks up to (the heater hose)?

Might check that if it is boiling gas, if it is not there it could be an issue whether the coolant line is hooked up or not, I think it needs the spacer to keep the carb cool"ish"

Just thoughts.

See Ya,
Mike

Has the water plate under the carb, just bypassed it this evening so unsure if it fixed anything yet. Only vacuum leak is at the throttle shaft but ive seen worse. The dizzy I have is vacuum advance only, no mechanical advance so disconnecting it would be a bad idea.

65_Rat_Merc wrote:The dizzy I have is vacuum advance only, no mechanical advance so disconnecting it would be a bad idea.

Yes those distributors are the worse, you can see about finding a later one that is both mech and vacuum. Now I kinda wish I had not tossed the one off the '72 200 in the scrap heap, sometimes I don't think things through (actually let me check maybe I didn't, if not I can send it too you)

See Ya,
Mike

Much appreciated, not sure how much shipping would be from Missouri. I can probably find one locally if I look. What years/model cars am I looking for to get the dizzy?

'68 to '72 have a mechanical & vacuum advance, can be any 6 (170-200-250), a much better distributor. You can also go '73-'74 for Duraspark or 75 up for the Duraspark2. The Durasparks are electronic pointless ignitions so they would require the ignition module as well.

65_Rat_Merc wrote:Much appreciated, not sure how much shipping would be from Missouri.

Knowing me I threw it in the box to go to scrap metal place but I can look tomorrow to be sure.

See Ya,
Mike

lavron wrote:The Durasparks are electronic pointless ignitions

Then, what's the point? (Couldn't pass that one up)
Jim

Jims65cyclone wrote:Then, what's the point?

There isn't one

I can't find that distributor so I think it went away.

See Ya,
Mike

Jims65cyclone wrote:

lavron wrote:The Durasparks are electronic pointless ignitions

Then, what's the point? (Couldn't pass that one up)
Jim

BOY,everyone wants to be a stand up comic (couldn't pass that one up neither) ..............pop

A little update:

Problem isolated to the enrichment valve sticking when the carb gets hot. Working on a fix, probably just soaking it in carb cleaner over the weekend and exercising it with lube. Thanks for the info guys!!