Welcome to Allpar. There may be a label under the hood or in the engine compartment that looks like this: FA90F3B6-4EEA-4555-9114CC9CAF8F4273.png
Many vehicles had an OSAC valve to delay the advance vacuum supply to the distributor for NOx emission control. It was usually mounted to the air cleaner.
Something this old and going through what it did may need a carburetor rebuild as a next step. Do you get a squirt of gas from the accelerator pump when opening the throttle?
Thanks for the welcome, After the poor van was up to the windsheild in sea water from hurricane sandy evrybody said scrap it.
My son bought the 1978 dodge tradesman maxivan in 2012 for $1,500 in California, he wanted to travel the country after being discharged ffrom the Marines. At first I thought he could of better spent his money than on a gas guzziling money pit. I drove it for him from San Diego to New York and gotta admit it was pretty cool. Not one problem, cross the dessert in July and plenty of power up mountains even the Boarder Patrol loved it. The old van earned it's respect from me. I parked it in Brooklyn without a spot of rust. Then mother nature gave it a salt water bath in the Atlantic Ocean durring hurricane Sandy ( my wifes name).
i was doing good cleaning it up. All I spent was $100 on a starter, oil and lubricant spray. I cranked the water out of the cylinders cleaned the carburetor and it started, then New York City impounded it. City law 7 days parked on a street without being moved is considered abandoned That sucked, we had to pay the city $300 for a van that was under sea water.
After being startred it didn't seem to be burning any oil, and the trans. seemed to be ok at an idle speed with just changing the fluid.
So now I am going all the way, Everybody thinks I'm crazy except my son, he says you have to drive it cross country to understand..
I have a carburetor and distributor ordered from autozone. took advantage of 25% off mail order.