I finally found the problem. After rebuilding the carb, replacing the mixture needle, and replacing the intake manifold gasket I still had the same problems. I just couldn't get the carb to run when I opened the choke plate up. It had to be almost all the way shut to make it run. I stumbled onto a post about the Idle cut-off solenoid. This shuts off the idle jet to keep the engine from dieseling at shut down. However if this solenoid doesn't ever open you won't get any fuel to the idle jet and therefore the engine won't run unless it is fully choked to balance out the air/fuel mixture. I bypassed the green connector and just wired them together and voila...the engine ran again. I don't know if I really had to replace the mixture needle but the carb needed the rebuild and I did have a vacuum leak at the intake manifold. I just thought that I would post this so if others have the same problem they would have another possible solution.

Cool! Thanks for sharing the solution <img src="/forums/images/graemlins/kewl.gif" alt="" /> At least everything is all new and happy and you learned a bunch bout your carb, right?

-Scerb

True. I was really surprised by how easy it was to rebuild the carb. All you have to do is do it in order and keep things organized (I put everything in numbered ziploc bags) and it's like putting together a big puzzle. Thanks again for writing the Carb FAQ it helped out alot.

OK, well I thought that I had fixed it <img src="/forums/images/graemlins/frown.gif" alt="" />. It will at least run now and I can get it to idle but not well. It still wants less air and more gas. The mixture screw is at 21/2 turns like it should be. What do you guys think about this idea. I was looking at the manual for my mityvac handheld vacuum pump amd it said this:
Worn Valve guides
Worn valve guides admit air which upsets the air/fuel mixture. The vacuum gauge reading will be lower than normal and will fluctuate rapidly in a range of about 3" HG. As the speed of the engine is increased the needle will steady.

These symptoms are alot like what I've got. I can't get the mixture right no matter what I do, the reading is low and the needle flucuates or shakes instead of being steady.
How many of you out there vote for worn valve guides as the cause?

How many miles on that engine? It's possible the guides are at fault, but is it using a lot of oil?

Also, 2 1/2 turns out is the *starting point* for your carb, you may need to vary off that a bit to get the mixture right.

Dave

I guess the other $5 question is-- before you dug into the carb, did you have bluish smoke at startup that went away after the truck warmed up? This points to valve seals usually.

It has about 170k miles on it. I'm not sure about the bluish smoke. It smokes, but it is mostly white from the bad head gasket. When I bought it the oil was down two quarts. Also the old spark plugs had lots of oil on them. Not carbon build up but just plain liquid oil. What would cause that? All symptoms are pointing to a rebuild but I don't have the time or money to do it right now. I just need it to run for the summer months, but it has to pass emissions.

If the HG is bad, the engine will not idle right at all. it will miss and jump around a lot.
I would do a compression check and see if it is worth doing the HG. It isn't that hard of a job. If you rebuilt the carb, you can handle the HG <img src="/forums/images/graemlins/smile.gif" alt="" />

Here's another question. A compression check only tells me wether my engine is not holding pressure, but it won't tell me what part is to blame, right? What I'm wondering is if I should worry about rebuilding the bottom end at all. I could do the HG and have a shop do the head for not too much. The oil pressure seems fine and as for the rings on the pistons, that might be something I could live with for a little while. I would much rather tell my wife that the head has to be rebuilt than tell her that the engine needs to be pulled. How long can I get away with not redoing the piston rings, and how much does a good shop usually charge for re-doing a head?

If the compression isn't what it should be, you can sometimes tell if it is a leaky valve or bad rings by checking it once "dry," and then again after squirting some engine oil into the spark plug hole.

Theoretically, the oil will help bad rings seal better during the compression test, so if the compression goes up significantly, the indication is the rings are to blame.

If the reading doesn't change much or at all, you probably have a leaky valve(s) (or a bad head gasket).