My ’65 Skylark, with the 310, automatic trans, just started stalling at idle today. Bone stock, 2 bbl. Running rough, exhaust sounds different, more muffled. The symptom appeared when I was driving around in stop and go traffic, and seems to be more acute the hotter the engine is. Sometimes it will hold an idle, sometimes it won’t. Oh, yeah, and when it quits, it starts hard. The car is amazing for how it starts on the first turn of the key, always, so this is new, too. Down on power, torque no longer sweet, obvious increase in fuel sucking. 51,000 miles on the car, it’s run absolutely beautifully since I bought it just over a year ago, no troubles. One thread I found suggested leaking at carb base, but said you’d see black smoke out the tailpipes in that case, which I’m not seeing. I’m going to take her to my amazing wrencher ASAP, but if there’s anything obvious I can/should do, advice appreciated. Part of me thought ‘maybe it’s just it was set up for the cold temperatures, and needs to be adjusted’, as it was 40 or 50 degrees today, vs. the 20-30 it’s been for weeks without count. There’s a rusty hole in one of my (about to be replaced) mufflers, and I wondered if something broke loose and is partially clogging that pipe, causing mayhem. Thanks to any for advice or counsel. My guess so far via thread searching "When you say 1000 rpm idle in neutral, and 450 rpm idle in gear that seems to me like a vacuum leak somewhere.” And "Either vacuum leak or your idle circuit in the carb is gunked up. Pull the carb apart, hose all of the orifices with carb cleaner, blow it out with compressed air, and reassemble."
Could be a lot of things. The process is to start eliminating things. Could be a spec of dirt on the needle valve. My 65 Special recently had a crack on the brass float. I would start by verifying the dwell and timing. Then check the float level. Could be a cracked rotor or cap.
If the car had been running well up until just recently, it's not likely that the timing moved itself or that the carb. all of a sudden needs a complete rebuild. Based on what you're describing it could be a clogged fuel line. I've had a number of 60s/ 70s cars over the years, and typically, unless the gas tank has recently been cleaned out, there is a lot of sediment and debris in there that can clog up the "sock" filter in the tank. The car may start well, and run ok for a little while, until the debris gets pulled off the floor of the tank and sticks to the filter. There could also be gunk further up the fuel line. It could also possibly be the fuel pump itself. One test for proper fuel flow would be to disconnect the fuel line from the carb, attach a 1-2 ft section of rubber fuel line to the end of the metal fuel line, and have a catch can (coffee can works well). Be sure to disconnect the coil wire from the distributor prior to cranking the engine-- just to be safe. Have someone crank the starter while you hold the fuel line over the catch can. You should see a good, steady amount of fuel coming out. If no fuel, or weak trickle only, that's likely the culprit. You mentioned about checking for vacuum leaks, like at the base of the carb, etc. Do that as well. Make sure everything is tight and no vacuum-related hoses or caps are missing or broken. Hope this helps.
If the rubber fuel hoses are original. replace them.my65 had started running weak and seen the rubber hose seep fuel then suck air into cracks.
It is possible the internal part of hose broke off pieces and went into needle and seat. If they are 45 year old hose they should be replaced
Thanks to all for the time and counsel - Alec296, our first responder and big winner: it was points. Once replaced, the car starts on the first turn of the key, again, idles perfectly. I'm a little embarrassed for having panicked, but appreciate the building of the knowledge base. Hopefully this thread will be clicked on in the future and someone says 'ah, a $6.83 set of points.' For those wondering above, the car was kept up with over the years prior to me getting it...hoses, rubber items are (happily) not original.
