[rhstewart]

Thanks for all the help. Here’s what I did…

Looked at the passenger side exhaust and there doesn’t seem to be a heat riser valve. I couldn’t see a counterweight or spring. There’s a spacer of some type but there doesn’t seem to be any external hardware. I live in the Pacific Northwest and I doubt that low temperatures are a big concern here.

I did RustyPile’s checks and found the accelerator pump was not working. The accelerator pump lever was not engaged with the bottom of the spring loaded bolt in the intermediate lever; it was off to the side. I took off the intermediate lever and bent the pump lever so it lined up with the bolt. I could hear the spray when I pulled the accelerator lever. I have no idea how that got that way.

I tried to start it again. It took a while to start like usual and did eventually start. While it was trying to start, the timing light wasn’t activated. Is it normal for the timing light to only be activated once it gets running faster and starts? Or should simply cranking the engine get the light going?

It eventually started.

Based on Dead Parrot’s advice, I checked around for vacuum leaks with starter fluid. Nothing jumped out at me. Maybe a small one where the booster is connected directly to the manifold. I sprayed it and it sped up a bit.

I checked the timing and it was where I set it; around 8 degrees BTDC. Pulling the vacuum pot off the ported vacuum there was no change. I connected to the manifold port and it advanced to about 26 degrees BTDC, which matched expectations. I left the hose connected to manifold vaccum for experimentation.

I let the engine cool for four or five hours so I could test it cold. Later in the day, I tightened the brake booster connection in the manifold. It started up with choke and stopped like normal but started again pretty quickly. That’s better than before. I assume that’s the accelerator pump working now.

I took the truck for a ride. Ran fine. Good even. I swapped the distributor vacuum back to the ported vacuum and drove for a short bit. That also seemed fine but I didn’t have time to go for a good ride.

Thinking about the vacuum checks I dug into the PCV system. Because of the 283 manifold on the 350 block, the crankcase ventilation is strange. The manifold has an oil filler neck but the block does not have the breather port at the back. Instead, the base of the carburetor is connected to a PCV valve (which seems to be working—it’s not stuck and I can feel the spring), which is connected by a long 1/2” tube to the oil filler cap. I disconnected the hose from the cap and stuck my finger in there while the truck was running. There was vacuum and the engine sped up a bunch. There was engine smog coming out of the oil filler cap. I think the cap is sealing and the PCV valve is successfully sucking gasses from under the manifold so it is doing what it is supposed to. How much vacuum gets lost from the PCV system operation?

Thanks again for the good ideas and help. We’ll see how it goes next weekend.

Cheers,
Rich