64 Riviera rough rough idle

[gdiwicker]

I have a stalling issue that happens when I've been driving for about 30 minutes to a hour around town. It's happened on the highway and while I come to a complete stop at a traffic light. Also, after I have let the car warm up in the morning, EVERYTIME I throw it in reverse for the first time, it stalls but always starts right up again. *That was a week ago. Now it won't even stay idled unless I dial in about 12-13k for the idle. I never let the tank get less than half full.
This is what was done:
replaced fuel filter
replaced gas cap
checked gas tank vent hose
cleaned and vaccum tested the carb
timing checked
checked for spark
compression test
inspected and replaced spark plugs *#6 was grey, the rest were normal)
replaced plug wires

Any thoughts?

Thanks,
Ryan

PS-compression results
rear
Pass. driver
140 -- 160
150 -- 120*
155 -- 145
???? -- 150 couldn't get under the compressor and alternator
front

[Dr. Frankenbuick]

Could also be ignition.

[gdiwicker]

I tested for ignition spark as prescribed by MSD. I used a jumper wire and the was spark when I grounded/ungrounded. Could it be valve leak-down? Don't want to test for it and take things apart if it's not a possibility.

[Aaron65]

Vacuum leak somewhere???

[Maikl]

Sounds like the same problem I have with my 56 Buick. In my case, it is also impossible to set the idle as low as required.
Have not found the source of the problem either, but have checked everything you did plus manifold vacuum and it is okay, but needle of the gauge is shivering, which indicates problems on single cylinders rather than a general problem with vacuum...
My next guess is sticking valve(s) and/or worn camshaft.
Does anybody think it would pay to check for an ill mounted timing chain ? (Bad gasoline from long-time storage in the tank is another point that might contribute...)

In your case (with these different compression readings) sticking valves seem even more likely than in my case.

Best regards
Kindacool

[rcull]

A couple of things I might look at in you fellows case is again in the distributor, check the shaft for side play. You shouldn't feel any. If it is just detectable it is probably serviceable. If it is obvious, it should be fixed.

Maikl, if your time chain was out a tooth, it would have never run well. In both your cases timing chain stretch is a good one to check. With a wrench turn your crank until the timing marks are on zero. Then turn it backward until you feel the chain "pick up" the valve train. You will have to do this several times to get used to the feel.

[Maikl]

Thanks rcull,

for hinting at that. I will check for that before proceeding. What should the "feel" of the timing chain be ? I guess picking the valve-train up without delay ?

Does the different look of the spark plugs on the attached picture tell the same story of a possible distributor problem ?

Thanks !
Maikl

[gdiwicker]

I have tested the problem with a stock distributor and had no problems. After we put the MSD back in the timing was at 20 degrees advanced. I couldn't even retard it much with out it dying. Any thoughts?