Carb Help??

Folks, I need some help. I've searched the forums for an answer to this question, but I haven't found an answer.

Finally started up my truck after many years of sitting, and it doesn't idle well at all. In fact, unless I choke it slightly, it will die. I've tried adjusting the mixture screw, but it doesn't seem to have an effect. Runs okay and doesn't miss when I give it throttle. It seems more like a fuel problem, although, I guess it could be ignition-related as well. It's got original ignition system components (plugs, wires, points, etc), but a new fuel pump and a carb kit as well.

Any help would be appreciated.

Possibley a lean idle mixture caused by a vacuum leak?? Check for a split vacuum hose leading to the windshield wipers shutoff valve.

Could be alot of things. It's very important to follow the tune up proceedures in the manual. Does it run on when switched off?

Have you tried some basics like running carb cleaner through it? If it seems to run well accept at idle I would think that it could be a vacume leak like was stated or more likely just gunk in the carb. If the truck sat for a long time spiders have the nack of getting into the little openings and building nests and then dieing leaving a spider body to plug up the holes.

Start with some gummout and see how it does after that. The nest step would be to carefully pull the carb off and appart and clean it out.

Also check fuel filters for junk. You could have a plugged filter form gunk in the tank.

If the carb is running rich, the plugs might be fouled. Long storage can kill your fuel and condensation might have added alot of water in the tank. If it runs decent going down the road, it may not be ignition. A few things to check.

I just had a similar carb problem with mine. Stalling at stops, running rough, Would only run if idle mixture was screwed all the way in. I rebuilt the carb and still no difference. Checked everything (gas tank, coil, fuel pump, ignition etc. etc. etc.) Spent alot of $$$. Then I replaced the carb...now its running fine again. At least I have peace of mind with all the new parts (and no piece left in my wallet!). :doh:

After you get all avenues checked, maybe the carb is bad.

You didn't mention how long it's been on the road. If it is varnished up it should clean up over a little time and driving. Sometimes and only sometimes you can rev it up a ways with the air cleaner off and quickly cover the air intake with your hand till it starts to die. That makes for a strong vacuum and could help clear any passages. The idle circuit is not used above idle but the momentary closing of the carb might help clear the junk out. I would put some miles on it and look for vacuum leaks like Joe says. You could get some rubber carb caps and plug everything pertinent and see if it improves. Good luck...

Gents,
Sorry it took so long to get back. I was going to pursue the vacuum leak suggestion, but I managed to kill my batteries first (still not used to that ON-OFF switch). I'm leaning towards the vacuum leak suggestion since I'm pretty sure my vacuum pump is not working anyway. I was going to try temporarily pluggin most of the lines to see if that improved anything. The carb was cleaned pretty good when I put the carb kit in recently.

Sounds like an idle jet clogged to me. If it runs OK off idle or you have to nurse it to keep it idling, then the idle jets are either partially or totally clogged. The main jets must be somewhat clear if it runs ok in higher RPM.

To avoid disassembly of the carb, I've had luck sometimes just removing the idle mixture screw, then using some 2+2 carb cleaner, and flushing back up through the passage, and following up with compressed air. If its stubborn though, you may have to pull the carb apart.

I do a lot of storage vehicles in my shop, and gas nowadays rarely lasts more than a few months unless you add Stabil or some other like product. I've had fuel go bad in as little as 3 weeks. Usually what is in the carb (because its such a small amount) will die before what's in the tank.

Hope this helps. Carbs aren't a "mystery box"

If you left the ignition on long enough to kill the batteries, you probably also killed the coil. If the truck won't fire, then you probably need a new coil.