Hey everyone,

So, I've got a 1980 B310 with an A14 that's got a really weird idling problem. It has the stock carb, but just about all the emissions equipment has been taken off, the vacuum lines capped. Only vacuum line going to the carburetor currently is the vacuum advance from the distributor.

Here's what happens...I'll start the car up when the engine is completely cold, and it'll start right up, idle abount 1500-2000 rpms, but a little rough. It smooths out after maybe 30 seconds or so.

The car will idle (although high, cause the engine's still cold) until the engine warms up, at which point it'll idle far too low and feel like it's trying to stall (about 4-500 rpms). If the engine warms up all the way, it'll simply die without trying to idle if I release the gas.

This happens EVERY TIME I start the car after it's been sitting for more than a few hours. However, the problem COMPLETELY goes away if, after the car warms up and won't idle, I shut off the car for a few minutes, and then start it up. It idles and runs beautifully after that (about 900rpm idle), and will continue to do so for the rest of the day as long as the engine doesn't get completely cold. The fact that it runs so well after I leave it off for a few minutes leads me to believe it's not a vacuum leak, but really, I'm pretty stumped.

Any ideas? I really just don't know where to start

Thanks in advance for your help!!

I had a similar problem recently. Now this type of problem is difficult to diagnose, so don't get discouraged if these suggestions/guesses don't work. I eventually fixed mine.

1.
On my A12, I found two vacuum leaks . Once I fixed those, then the car idled too slow. I had to turn the curb idle screw in to raise RPM, then adjust mixture again.

2.
Later it had an idling problem. Sometimes it would barely idle, then for a few days run perfect. Eventually it got worse and worse until the problem because urgent to fix, it wouldn't idle at all and barely drover. Turned out to be crud in the carb -- not in the fuel bowl -- but in the jet wells at the bottom of the fuel bowl. Removing the jets from outside (let gasoline run down on cold engine) and rinsing them, put back together fixed it.

3.
A14 experiences. Some have a "dashpot". The idle screw doesn't hit the stop on the throttle shaft bracket, but stops on the dashpot. This is often a source of erratic idle speed on many older cars.

Air leaks generally make it idle too fast. But if you compensate by changing idle screw or mixture screw now everything is off...

1. Alright, I checked for vacuum leaks on all the caps that I've put on, and found one that was basically ruined. Replaced, but still didn't fix the problem. Is there a way to tell if the base gaskets are leaking?
2. Would spraying carb cleaner down into the carb help at all? I'm not really confident in taking apart the carb, last time I tried to rebuild it, I actually cracked the float, and that caused some REAL problems. Or is removing the jets from the outside (?) fairly easy to do?
3. I've checked around the dashpot, and haven't found any signs of a problem, but basically, it's ridiculously hard to diagnose, because it only does it 1-2 times a day where I'd be able to do something about it.

Also, it will sometimes try to die after coming off of the freeway...

I was reading in the tech section about the anti-dieseling solenoid being a potential problem for idle, so I'll investigate that tomorrow.

Thanks for the suggestions! I really appreciate the help.