My car sat for 20 years in a garage. It now runs and drives, but I'm wondering if any of the vacuum-actuated parts (TPS, etc) could benefit from any kind of service. I'm wondering if the seals or other parts on these components need to be checked for sticking/rot/losing elasticity. I've replaced a few of the other seals on the car (fuel gauge seal, some vacuum hoses, fuel hoses, etc). I'm just concerned about the ones I can't see.

No responses?! Is this a stupid question that even a newbie like me should know? Are these parts just not serviceable? Can they be overhauled? I've been told they either work or they don't but I thought it might be possible to overhaul them. I can pull a vacuum on them with vacuum pump and see if they hold the vacuum, but then what if they don't? Some of these parts are NLA or are very expensive. Thought I'd see if they can be serviced.

Tps is mechanical. It has wipers that wear. If you have d-jet you will have an MPS that has a bellows that fails after some time. There are procedures online that show how to test and calibrate.

Hmm, vacuum operated parts? Mps, distributor advance/retard, decel valve. Nothing there to service that I can think of. Probably different with an ljet