I am pretty sure I've zeroed in on the cause of my intermittent idle stalling and rough deceleration stalling on the '82 22r pickup.

I tested the fuel cut solenoid, and when power is removed from it, it behaves just like the random version of it: not idling, requiring pedal pressure to keep idling. I manually attached power to it, and it returns to good normal idling.

I searched around the internet to find a few others with the same exact problem. They all had the same symptoms, and one of the people just wired his to the battery and later installed a switch to it. He said the problem never happened again after that. I've tried all kinds of things but have finally narrowed it down. I was even thinking of EGR and all kinds of other things.

The hesitation I have to hardwire it to a switch is that that would be sidestepping the issue. I never did read of these people finding the root cause of the problem. It seems to be something very few people have tracked down a proper solution to.

I would like suggestions on how to find all of the points in the electrical circuit and/or vacuum circuit that could be affecting the solenoid receiving power. I know on my sort of later year, it turns the solenoid on based on variations in vacuum conditons. In other words, when vacuum pressure changes because the engine is accelerating or decelerating, the solenoid gets turned on if I'm decelerating or idling (high vacuum) or off if I'm accelerating. There is a vacuum switch, I think it's the one mounted on the valve cover that does the electrical switching for this particular year range.

On older models, the solenoid was turned on by the ignition being in the on position. These must have been the non-catalytic versions, because the word out there on the internet and in my manual (chilton) is that they added the low-vacuum shut-off to prevent extra fuel to after-burn and overheat the catalytic converter.

I know my catalytic converter is aftermarket and whoever installed that cut off the o2 sensor, I guess so that no false o2 reading would affect anything. It would have been better if they'd had a bung welded into the o2 sensor tube on the aftermarket cat and hooked that up. It's only a remote possibility. It's a pretty compact cat, and I think it's one of the high-flow ones. Of course, they did nothing to the intake side of the engine!

The reason I am starting this new thread is because I've ruled out the EGR system in a test so simple that I'm surprised I didn't think of it earlier. So the purpose here in this one is to try to dig up information on the circuits involved in the fuel cut solenoid system, both vacuum and electrical, because I know both systems are involved. There may also be issues in my key ignition switch, because the key does stick forward and needs to be manually pulled back during starting. I know earlier models had the ignition switch turn the fuel cut solenoid on directly, and when shut off, it disengaged fuel from the idle circuit to prevent dieseling. But now there is another factor in my system, and I would also like to know what is more likely to have a problem: the electrical circuitry, or the vacuum circuitry. The vacuum stuff doesn't really have any reason to leak, unless hoses crack or something is loose, but it's not out of the question. The electricals can be hard to trace, and often lead to frustration since it's not easy to see what's going on. But if I get a little bit of help or information, I could be more easily solving the problem.