1975 stalls after engine is warm weber 32 adfa

[NittanyGamecock]

I have read the various postings of similar issues on this forum and I've tried just about everything and I am at wits end. I've tightened nuts on intake manifold, replaced hoses, put on a new idle solenoid, tuned the mixture and I cannot figure it out. The only other items I have this time would be debris in the fuel filter which I have changed twice and I have not changed the gasket and or spacers on the carburetor. Any suggestions or troubleshooting tips would be appreciated. Thank you.

[nelsonj]

Vapor lock seems to be the most common cause. When the car won't start, is it getting fuel? I've never tried but I was tod you and remove the air filter and top of carb and see if the floats/resivors. If there is no fuel work backwards from the carb, fuel pump, fuel lines, tank. First Remove the cap and see if that helps.

First figure out if the car has fuel.

[blazingspider]

It would help a lot if you could provide more information. Why do you think it's the carb? When the engine is warm can you see any gas being squirted into the primary barrel of the carb from the accelerator pump jet when you work the accelerator linkage?

Are you running the dual point distributor as it was originally designed or are you running one set of points?

Let us know.

[NittanyGamecock]

Thank you for your responses.
I'll try to answer to the best of my ability. The vehicle will start up every time and with relative ease. It's only at times-not everytime, when idling at a stoplight or stopped in traffic, maybe with the radio on or with the lights on (under somewhat of a load but not a heavy load). the vehicle will slowly drop the the idle and then quickly stall once it starts dropping but only when the vehicle is warm.

I was assuming that it has some type of an air leak but it may not be. I have not replicated the issue in my driveway with the air filter off. I will have to try that to see what the carburetor does when it idles and then stalls at that specific point.
The previous owner converted to electronic ignition so it does not have the original points ( and I replaced the electronic ignition when I was having another issue about six months ago. The problem with the vehicle not holding it idle and installing has been an ongoing issue since I first purchased this in February 2016. Thank you all again for your time.

[wideopenplains]

Hey! I'm jumping in here cause I seem to have a very similar issue. Car cold starts fine, but stalls out when warm, then cranks and cranks without restarting until it's been sitting for quite awhile.

Have you found out anything from your troubleshooting? I'm definitely a newbie, but would love to learn from your issue if you fixed it!

[NittanyGamecock]

Sorry for the delayed response. I think I have narrowed it down to the alternator. When I am sitting at a stoplight the fan, the radio and brake lights are on and that's when my RPMs drop. I may upgrade the alternator and see if that helps. The battery registers under 14 V when the car is running and under a somewhat heavy electrical load.

[NittanyGamecock]

In case anyone is interested, my issue was the result of a poor alternator. Replaced it with a 95 amp alternator and I no longer have the issue.

[md88plt]

Have you checked your distributor cap? There are some poorly made Chinese distributor caps that when heated will change internal resistance and render your car dead. Once they cool off, all appears normal until they are heat up again. You can diagnose this by measuring the resistance between the internal contact and external ht plug inlet at cold verses hot and see if there is a significant change. If you suspect or diagnose the distributor cap as the issue, replace with an Italian made cap from a fiat parts supplier. Vicks, Recambi, Bayless etc. My opinion is that it is not your carb.

[NittanyGamecock]

thanks for the suggestion md88plt. as you and some others have mentioned, the carb was not the issue. i upgraded the alternator and it has not stalled like it used to when stopped in traffic, warm, under "heavy" electrical load (fan, radio, lights, turn signal, brake light). i will check the distributor cap just to see if there is any change in the measurements when warm. thanks again.