IMHO, you are placing more concern than is warranted on the way the engine runs cold. That engine needs to go for a good run and get warm. Go ahead and do the ATF fuel treatment, and put a can of Seafoam in the crankcase. Advance the timing a bit like Macrobb said, when the engine is cold (easier of the hands
). High idle when cold should be about 850 to 900 according to spec. I prefer mine to idle on the high side, but I have a manual transmission.
Is your cold advance solenoid working? When the engine is cold it advances the timing about 3 degrees.
Take it for a good run and check the timing when the engine is warm. Don't worry about running it a little advanced. My 1992 7.3 NA ran like a scalded dog @ 11.5 degrees advanced! I backed it off to 9.5 just to be cautious.
This is kind of what I am coming to, myself. So I'll agree... with a caveat. That caveat being that this thing is SO rough at first, I don't think anyone on here would NOT be concerned, if they were right there with the truck during that time.
I'll be adjusting the timing as soon as I can. Today turned into a day of rest. I was just way too tired to get anything at all done. Took a 3 hour nap, and then there wasn't enough of a day left to drag all the tools out to the truck, do some work, and drag all the tools back.
I sometimes wish I had a garage or shop to work in. As it is, the weather has an affect on whether I work. And I can't just leave my tools out, but covered... tweakers would steal them before I got my front door closed behind me, when I come in at night. I only have just so much energy, and the tools are heavy. Especially when dragging them over uneven, steep, sometimes muddy and slippery ground. Everything affects everything else. But I AM working on building myself at least a crude, "defensible" workshop out front that I could pull the nose of the truck into.
So what I said I would get done today, I'll try to get done tomorrow. Then maybe the IP timing on tuesday. We'll see.
I AM going to try to get the IP timing up, and see if that makes a difference. THEN... I won't be getting the seafoam, but... I will fill the fuel filter with atf. Move the truck to a level area. Check all the fluids. Then take it down the highway for a good blast.
Cold advance. Never quite sure what people mean when they ask that. The solenoid on the back end of the IP does seem to work. The solenoid that sits on top of the front of the IP, and pushes against the throttle linkage, does work.
And as for the flat lever on the bottom front, driver's side of the IP... Well, it does push in, with a finger. And it does go in and out, when the throttle linkage is worked. So the lever works. But again, I have no idea whether what is inside the pump is stuck or not.
Advancing the IP some, and trying to get the problem worked out that way, then making that highway run, is the last thing I want to try, as far as the top of the engine, and fuel delivery is concerned. I feel like at that point I will have had due diligence to try everything I could other than replace or rebuild the IP. It will take a long time for me to save up enough to do that, so it would be time to just drive it with problems and/or check into other possible problems
If I keep having problems after that, I intend to take off the valve covers and check out all the rockers.
I am not getting any "chuffing" out the exhaust that would indicate a problem with the valve openings, but you never know.
I do still have other things to work on.
Got to replace the wiper motor.
Got to rebuild the support behind the headlights on the driver's side. (Apparently there was an accident or something in this trucks past, that someone tried to repair with fiberglass and it was too thin. I'll cut a piece of tin, and make a repair plate instead.)
Got to run new circuits with relays, for the headlights.
Got a lot of minor electrical faults to trace out and fix.
Got a lot of cleaning to do.
Got a whole army of mice and/or rats to get rid of.
And more. So there will be no dearth of projects on this truck for a while.
I think it would be a really good idea to run a couple of tanks of fuel through it. Get some miles on it and see what it does.
Yep.
Time. Gonna take some. I don't have a budget to just get out there and drive off a few tankfuls with no other purpose.
And will have neither the budget nor the purpose for at least a while.
It'll get done, eventually.