CHECK FOR VACUUM LEAKS
what is vacuum gauge reading
what is fuel pressure reading?

does the engine vacuum change when brake is pressed or released? sometimes the break booster has a leak and it causes rough idle (disconnect the vacuum line to the brake booster and plug it somehow.

this is a vacuum leak problem for sure

 

I would not expect the new bowl vent solenoid to make any difference. It's an emissions device that dose not cause running issues. Before the solenoid was added/used, gasoline vapors would just go straight into the atmosphere. The clean air people didn't like that, so they had those gasoline vapors routed to a carbon (charcoal) canister. The bowel vent solenoid is "open" when the engine is Off, and closed when the engine is running (i.e. the carb vents internally when the engine is running) - meaning the bowl vent solenoid is not doing anything when the engine is running.

So, maybe it would be a good time to go back to the basics and check/recheck over the condition of the engine.
1) Do a compression test and leak down test (there is good thread on that subject).
2) Check the fuel system (clean fuel, good pressure)
3) Double check the ignition system (make sure the spark plug wires are on the correct spark plugs, recheck spark plug gap, verify coil and ignition module are in good shape.
4) get a vacuum gauge. It has a lot of good uses besides setting idle mixture screws (such as determining if valves are poorly sealing, if exhaust is too restrictive, etc.).
5) Check the ignition timing. If it is off, it may be due to timing chain stretch.

I think the typical rough-running culprits have been discussed, so now I recommend going back to the beginning and establishing that the engine mechanicals are in good shape - and recheck the work you did.

 

Thanks so much for the dialogue. Looks like I am off to grab a vacuum and compression gauge. I will search in the forum for appropriate tutorials.

I did notice that if I am idling and cut the wheel all the way either way and hold it, it feels like the truck could sputter and die.

The auto parts store I went to didn't have any vacuum hose in the right size so I picked up fuel line, which seems sturdier anyway; OK to use that for vacuum line replacement?

 

When you turn the steering wheel to full "lock" position the power steering pump is outputting max pressure so the engine is under more load. With a poorly running engine it is more noticeable (as in your case stalled the engine).
Using 3/8 inch fuel line for vacuum (I'm assuming we are talking about the line to power brake booster) is not the best idea (I think it is too thin walled and may collapse on itself with age) but for a while it should be fine. Obviously the other vacuum lines are much smaller, like 5/32" and a couple of feet of universal vacuum line should work well.

 

Just poking around the forums, I saw people talk about their truck running rich. I took off the air cleaner bowl and looked down into the carb while idling and I can see liquid fuel dumping in... fairly steady stream. Would that much fuel cause the engine to run rough? I have a flexible fuel line and pinched it closed for a while... the truck never did die (or even sputter for that matter).

I picked this truck up and discovered that the smog pump and associated apparatus was removed. Everything else looks to be stock.

Are there any steps I can take to get the mixture a little more lean. The tag on the inside of the engine compartment says that there are no user-adjustable components. Is there something specific I can do to get the mixture a little more balanced (if in fact it is off)?

 

you need to rebuild your carburator
or check your fuel pressure reading

something is horribly wrong if you see fuel pouring into the engine at idle
horribly wrong.

 

Thanks for the replies, very much appreciated. I took Patrick's advice and tore down the carb, ordered a kit, etc. I had a question unrelated to the original post, so I forked it into this thread here.