I was asked by a friend to look at his 63 Nova, it was stalling out and he was concerned about driving it up to CT for the Area 11 meet next weekend. I looked at the car and there were many small problems, the most noticable and semed to be the cure for the rough errattic idle was the PCV was staying open under idle. I did a tune up by ear, and it was running rather good. Took it for a test ride, and it stalled rather abrubtly and would not hold an idle. I could get it to start but there was no idle. The spark looked rather weak at the cap from the coil. I am thinking it is the coil, and it is breaking down from the heat, I just think it is strange how it went from running good to junk in a matter of seconds. I told him to get all of the ignition tune up parts so we can replace them and rule all of that out, ANY IDEAS!!!!!
John

John, I would say your approach is good and logical, check put the ignition, coil and condenser, but also keep the fuel in mind, like something floating around in the tank or trash in the carb

Mack, I was thinking carb, but it does not happen under throttle, only under idle. I figure junk in the carb would show more under load. I will let you know tomorrow after I look at it again

John, I didn't ask what engine and carb, I was thinking six with a one barrel.

You got it a six and a one barrel/powerglide
John

Just a little info on the one barrel Rochester carb. fuel enters into the manifold thru several small holes just below where the throttle butterfly valve closes on to the throttle body, the vacuum is stronger there when the throttle valve is closed, causeing fuel flow thru the idle and low speed jets, then less as the butterfly valve opens and the fuel to these jets is controlled by the idle jet near where the Vacuum advance line screws in at, sometimes the passage to the idle jet fuel outlet will be clogged up by trash in the carb body. Try screwing this idle air jet out then back in to about 1 and 1/2 turns from bottoming out. Of course this applys to the Rochester model B, BC and other variants of the Rochester one barrel carb.

I give up!!!! I got everything tuned and running well, I hook up the vacume advance and it started missing, eratic missing. I disconected it and plugged it up and it continued. I am going to stick with the V-8's I changed the coil and the same thing is going on. I just can't make this thing out at all!!! Any help please
John 348

Hi,

I assume we are talking about the stock 194 6-cyl with the air-cooled PG?

Sounds like it is time to put a light on it and see where the timing is. With so much response when you worked on the vacuum advance it might indicate a problem in this area. Make sure the distributor has not moved due to a loose mounting bolt.

Ray, it is a stock 194 with the PG, the light is dead on at 8 BTDC, so I really do not know. The part that is puzzeling me is that it remianed after he vacume advance was disconnected. I did watch the vacume advance release. Maybe it is internal to the distributor? Oh well next step, but the more I am thinking about it you are right
Later, John

John, after the tuneup it ran fine till you hooked up the vacuum advance line to the carb? and then with the line hooked up to the carb things went South? Then when you unhooked the line from the carb it was still going South? even when you plugged the vacuum line or put a plug in the carb? Maybe you need to look at the carb Throttle base and check for a vacuum leak at the carb base. Inline sixes with one barrel Rochesters do strange stuff with a small vacuum leak at the carb vacuum port.

This is another thing to check.The early 194 & 230 cu. in. engines often had a worn and loose disributor plate. The vac. advance is connected to the plate and rotates the plate to advance the timing.If the plate is worn it will change the point gap when this happens. You can check ths out by checking the dwell when you connect the vav . hose .It should stay the same.Also could be tested by trying to move the dist. plate up and down--if it has a good bushing it should have no movement.This was a common problem in these distributors,WE used to stock and sell a lot of them when new because of this problem .A rebuilt dist. or a new plate would be a fix.Corvairs also had the same fault and they use the same plate. An improved plate is available from the Corvair vendors.
i installed an "IGNITOR" in my Corvair as it has its own plate and point gap isnt necessary.They are advertised in Hemmings and other old car magazines.Its a solid state electronic ign. system & easy to install.