Hi there, i just got me a beat-up 1985 D100 pickup for really cheap, and my buddy has offered to help me chop it for parts, so i can use them on my sl6 van, but i changed my mind on chopping it, because it runs very nice (once warmed-up)
Besides being extremely rusty on the underbody, the only drivebility problem is the cold start.
It starts right away, it runs for about 2 seconds and then it dies.
So i did some research in your article on the proper choke adjustement and it has left me a little confused, because it says,
that the thermostatic spring has to be adjusted at the correct tension before i attempt to do any other adjustements, but in the link provided it says, that adjustements to that assembly shouldn't be made, but rather the whole unit has to be replaced.
I'm running very low on $$ at the moment so i don't want to replace anything unless i'm absolutelly sure that the part is bad.
So i have moved to the next step and i have slightly spread apart the "u" shaped choke operating link rod, but it didn't make any difference.
I tried to go other way and squeeze it together a little more but all it did was to give me slower fast-idle.
So i adjusted it back to more or less the same position as it was before.
When cold starting, the choke flap shuts really good and it almost feels like it shuts with too-much tension, but then again how much is too much?
The guy who sold it to me, wasn't probably too big on maintenance, because when i first took-out the air filter it was so dirty that i couldn't belive the truck was still even running. I had to take a torch to the tires, just to take them of so i could see how the brakes look like.
So my question is: "Could it also be something as simple as dirty fuel-filter?"
After it warms-up, it rums incredibely smooth and quiet, but when cold it also has a delayed throttle response, which might be connected to the cold start problem.
Any suggestions or tips would be appreciated, but please try to keep it simple, since my knowledge of engines is pretty basic.

Sounds like the system is running lean.
Is the EGR or PCV valve stuck open? Are there any vacuum leaks?

Also check any sensors that my be in the system, a faulty temp. or O2 sensor can mess-up the cold performance.
DD

Thanx Doc, i will check those over, but i'm not sure about the location of the o2 sensor.

Ok, i did something i probably should have left alone and i need help to figure this out asap.
I got a new fuel filter and a new pcv valve, they were really cheap so i said to myself why not?
After installing the filter and the valve i drove down to a corner store and that's when it warmed-up and hit the curb idle.
It runs REALLY ROUGH, it has stalled a few times, the exhaust smells really bad and it blows out a lot of smoke and i have no idea why.
So i digged out the old PCV out of a garbage bin and installed it back,..no improvements.
Why is this happenning? I'm getting really frustrated, because if anything by installing new filter and PCV it should run better, not worst.
Any help would be greatly appreciated.
P.S.
One more observation i have made, i took off the hose off the pcv and the rpm's went up(way up) and there was lot's of residue that came out of the PCV.

I also took the PCV out while idling and covered it with my tumb, the vacuum is really strong, as it almost sucked in my tumb also the exhaust fumes or something kind of smells like gasoline.
I have tried to find gas leaks, especially in the fuel filter area, but i couldn't see any.
I have installed the original filter back....no improvement, so i put in the new one again.
I really need to figure this out, and it will probably turn out to be something stupid, but i'm baffled.

Problem solved, it really was stupid, as it turned out to be a stucked float in a carburator. It now runs like a swiss watch.

Good job working through the problem.
I guess it was not "running lean" after all.
DD