Spent the day Saturday on the car. Replaced the fuel filter, oil filter/oil and thermostat assembly. The front part of the asm. wasn't to bad but the connecting tube to the block was a pill. Had to remove the throtle body to get to the rear bolt. I was cursing the engineer who designed the exaust connecting tube to the TB, the rear bolt is a pill to access. When I removed the TB noticed an oil film in the intake manifol. Have to investigate how oil could get in there suspect maybe PCV valve. The old thermostat had a piece of a gasket sticking through it so that was probably causing it not to open or close all the way. Ran it for about 30 minutes on a short trip then idling in the driveway. Couldn't get it to stall but it did start to overheat after 30 minutes. Suspect that the last radiator sealant bottle I used may have partially clogged the radiator. Will try the vinegar trick and then replace the radiator if that fails. Will check codes and post next time I run it.

 

Put 1 1/2 gallons of white vinegar in the radiator and ran it on short trips for three days. Flushed the system after the third day. You could see a lot of floating gunk in the water which must have come from the radiator. The cooling fan used to stay on on hot days for minutes after the car was turned off. It's not doing that now which tells me it's running cooler. The oil in the intake was coming from the PCV through a connector hose. The hose was coated with oil. I replaced the PCV with a breather element and replaced the right valve cover to throttle body hose with a breather element as well. Sealed both TB connections. Ran the car for several trips of 20 plus miles making several stops with no stalls or overheating issues. Hope the problems are solved!

 

Your problem could be as simple as replacing the electronic ignition control module. When they get old, overheating causes them to fail and you car will stall. Sitting by the roadside for a few minutes allows the module to cool down, and then you can restart your car again. However, the problem will get worse and worse until you finally replace the module.

My family and I took a trip to Las Vegas from Sacramento years ago. The wife had had intermittant stalls previously. We got to Bakersfield without any problems. Between Bakersfield and Vegas, the car stalled 15 times. I got a new module and installed it in Vegas. Problem solved.

 

Ever since I did the vinegar radiator trick in May the car has been running great and has not stalled once. Problem was overheating without indication from the tamp gage. That's why it would start again after hours of sitting or the next morning. Felt great to get this issue behind us. I went ahead and painted the intake manifold and matched the breather elements to it. She's looking pretty and running smooth!