This has got to be a choke issue.

Car starts and idles great while warm. When cold it fires up quick but is very, very choppy and dies after 5-6 seconds(giving it gas usually worsens it, but seems to be key in the long run). Sometimes it will fire right back up. Other times I have to get out and manually release the choke, crank it over a few times, engage the choke and it will eventually start again. Then it's back to being choppy.

I have no idea where to start when adjusting the choke. Sites I have found leave me confused. If it gets any colder before I fix the problem I'm afraid this thing won't start at all. The carb that is on it now is a used one from a bonneville, and is unmolested.

Sorry if that was a pain to read. It's 4:00a.m, I have a migraine and it's a shitty day already

I should mention it smokes when it's in what I am now calling "chop mode" and that is the only time it ever smokes

 

Sounds like it might be a choke pull-off issue. That's the vacuum canister on the front/pass. side of the carb. It's job is to pop the choke open slightly as soon as the engine fires up (as soon as any meaningful manifold vacuum is present) to prevent flooding the motor out.

It could just be bad (not holding vacuum/not retracting when the engine fires up). Or it could be not adjusted correctly (the screw on the top of the arm determines how far open it pops the choke plate).

Check to make sure yours holds vacuum first. If not, buy a replacement from the local auto parts store. Then as a rough adjustment point apply vacuum to it manually (hand vacuum pump or using your mouth and a length of vacuum hose) and adjust it so it pops the choke open enough that you can stand a 1/8" drill bit straight up on the inside back edge of the choke tower without barely contacting the back edge of the choke plate.

 

That confuses me. what vacuum? Another guy sdaid maybe the fast idle needs adjusted?

 

trust me the are so finicky your best off going to person who specializes in them . I had one and got rid of it b/c an "expert" messed it all up. So find someone with a good rep and some cars that run them.

 

Nah, it isn't that complicated.

Check out the sticky at the top of this forum. https://www.thirdgen.org/forums/carb...e-rebuild.html

It's referred to as the "vacuum break" in the illustrations. Yours probably only has the forward vacuum break.

 

I'll give that a look, and thanks. also, if I don't get in and get my hands dirty with trial and error, how will I learn

Quick question:

When one puts their hand over the choke should the engine bog or should the rpms raise? Mine was bogging and even died a few times. I turned the fast idle screw in one turn, retried it and no more bog. Am I on the right track here?

 

If in open loop, it should make it go rich. If in closed loop, it won't affect it drastically until you really close off the opening.

 

gonna hold off until tomorrow morning when it's going to be nice and cold to see how it's acting now that I've played with the fast idle screw.

Went out a little bit ago and engaged the choke, fired it up and it was a noticeable improvement. Fired right up, rpms raised(dunno what to, I have the clock lol) after a couple minutes it didn't go down so I revved it a tad, idle dropped and all was fine.

So tomorrow morning will be the real test to see if it indeed is better

 

If the choke break (vacuum break, choke pull-off whatever you want to call it) is bad, the fast idle speed screw wont fix it. It might improve things a bit but, think about what you could be doing to your engine.

An engine running at fast idle is pulling a lot of fuel into itself with the choke closed. More fuel than it can burn. What happens to the fuel that doesn't burn? It washes down your cylinder walls and gets into your oil!

Before you go out and start it tomorrow, take off the air cleaner lid and note the position of the choke blade. If you shut if off when it was warm, the choke blade should be around 70 degrees (a warm engine should be at 90 degrees or straight up). Tap the throttle and the choke should snap shut (cold). When you start the engine the choke blade should open (as Damon said) about an eighth inch. It should do this immediately upon starting.

The choke break is easy to replace. It's held on by two screws and has a 'U' shaped linkage that attaches it to the choke and a very short vacuum hose that goes to the carb. You probably wont even have to adjust it.

EDIT: Check that vacuum hose for cracks or leaks. That can cause a choke break to malfunction as well.