This is similar to an older thread but I have an older car. It runs great when I first start it but after running about 15 to 20 miles it starts missing and whenever I come to a stop it stalls. I have replaced the rotor and cap and condenser. I have had the carb rebuilt. The timing is fine and the plugs only have around 5k. Not sure what else to do. The hotter the car gets, the worse it runs. Any ideas would be greatly appreciated.

 

I’m smelling fuel delivery. Pump starting to fail, vapor lock, porous hoses all suspects IMO. Visual inspection of hoses near tank and pump inlet. Does car have a return line? Vapor system functioning? Just some thoughts that entered my head.

 

Have you tried replacing the coil?

 

I was thinking vapor lock originally but not sure.

 

Haven't replaced the coil but will give it a try. Would heat make it fail?

 

Maybe a problem with the gas tank vent causing a vacuum and loss of fuel flow? Next time it happens, remove the gas cap and see if there’s any indication of pressure equalization.

 

Yes. When they go bad the heat will affect their performance. I would ****** one up from a local parts store and give it a shot...what do you have to lose?

 

Thanks everyone. From what I have read online its most likely the coil. Although unlikely the original, looking at it, it is pretty old. For around $25 I may just go ahead and replace it.
Not sure if I need the AC Delco E552 or U505. (RockAuto) There's no part number on the coil itself.

Update. As I was removing the coil the capacitor came apart in my hands. I have no doubt it was bad. Might have been original. At least I got 49 years out of it. Not sure what function the capacitor plays but it was obviously shot.

By the way I got 2.9 as a primary and around 12 for secondary when testing. Not sure what the numbers should be. However those numbers are when the engine was cold. It would get worse as the engine heated up.

 

Is it points distributor? How are the points?

 

I know you said you checked timing but what is it set to? Also have you checked dwell?

 

Coil and capacitor arrive today. Cutlass is now running better then ever and it only cost me around $30. Thanks everyone.

 

It's good to carry around a spare capacitor and tools to replace. I've had two go south on me within maybe a year, new ones are not like what people bought back in the day.

 

Good idea. I'm pretty sure the ones I replaced were original parts. Not likely to get 49 years out of the new ones.

 

I now keep a space set of points and capacitor in my cars tool box.

Last year my points Broke.
The little plastic "Cam" rider, snapped off its plastic base.
The missing cam-rider kept the coil "ON" at all times.
The car died instantly. The points only had about 5k miles.

Good Replacement points are hard to find.
Some Points, have a "Built" in capacitor physically attached to the point set.
It sounded like a nice idea.
The Built-in-Capacitor versions of points are crap, stay far away!

Not only did I have capacitor clearance issues hitting the Distributor cap, I could never
get the car to start.
I took them back and got the style with a Separately mounted capacitor.

Also, Look for the points that have a Screw down bolt for the mounting
of the Ground Wire and the Capacitor wire
The cheap points use a simple friction fit sprint to hold the two critical wires to the points.
The Screw is harder to install, but more reliable.


Poor: This type has a physically attached capacitor. It would not fit my distributor cover.





Poor: This set uses a friction spring.
At the top there should be a Screw, instead this cheap version has a metal plate, and you slide the wires under the plate.



This set has a separate capacitor.
Best: Note the wire attachment point is secured with a screw.
This is much better than the Friction Spring type used by some.

 

This is a long shot, but I have seen bad motor mounts cause stalling problems. The geometry of the throttle linkage can change when the motor shifts. Here's a video describing how to check them, with emphasis on SAFETY. (I.e., if you don't know what you're doing, take it to an expert.):


In the video he is working on modern iron, but the procedure he describes re: power braking is valid for our vintage buggies.

 

I go to ebay and get original OEM Delco Remy points and condenser. They cost little more but are worth it. Be sure they are the Made In The USA parts and not the stuff made in Mexico or China.