Similar Carb Issue

[Jimmymac46]

Not exactly like 69broncofun, I need to squirt the stock 73' Motorcraft two barrel as well, however. If it is warm and hasn't sat more than a few hours, it will light off. Seems as thought the bowl empties, but I never thought about the accelerator pump being the issue. Runs perfectly, smooth, acceleration is good, just a problem with cold or after a few hours requiring a squirt. New question as I didn't want to highjack his post.

 

[bax]

Sounds like normal carb function to me.

 

[Slowleak]

Yup..... sounds pretty normal. Crank it up, shut it off, look down in the carb while working the throttle. You should see it squirting fuel. If not then you have a bad accelerator pump.

 

[Jimmymac46]

Thanks gentlemen, I will check the accelerator pump performance. Bought this 73' (third owner) in 95', rebuilt the carb then. Probably time to do it again. Advice always appreciated.

 

[jckkys]

I don't see any issue and broncofun69 didn't articulate any symptom that would lead to a diagnoses. If the accelerator pump circuit weren't working the engine would stumble or die, when floored. A cold engine needs the throttle opened partially to give it a little fuel to start. The accelerator pump provides this. After many starts over time the driver learns how far to push the peddle. It's a matter of experience. For those of us who grew up with carburetors it's intuitive or second nature, like clutch engagement. To quantify the the peddle movement needed under all the different conditions is difficult and unnecessary. You just want enough, not too much. It's easy to flood the engine. The total number of potential accelerator pump circuit failures is too great to list. Trouble shooting procedures can be found in repair manuals for vehicles originally equipped with carburetors or on sights like Mikes Carburetor Parts.

 

[Slowleak]

I just went back and read the post from 69broncofun. He mentions that he is having to prime the carb from an external source. Not sure if that is what Jimmymac46 means when he mentions giving his a "squirt".

http://classicbroncos.com/forums/showthread.php?t=272655

 

[jckkys]

69broncofun doesn't even have his Bronco yet. What the seller he's buying it from said, can mean many things and he can't answer any any relevant questions or do any trouble shooting, with no Bronco. The PO may not know that after sitting for days or weeks that the float bowls are empty. The fuel is evaporated. The engine needs to have the float bowl filled before the engine can start. These days it's hard find people who understand carburetors, or know how to drive vehicles that have one. Currently, 69broncofun has no good reason to believe the Bronco he's buying, has any carburetor problem.

 

[73azbronco]

choke circuit not working?

 

[jckkys]

That's one of many possible explanations for what may not even be a problem. In all likely hood there may not be anything wrong with 69broncofun's new purchase. The seller pored fuel in the carburetor. That's all we've heard. And that's second hand. Why did he do that? What else did he try? That's diagnosing a brain tumor because someone saw a person rubbing their head.

 

[DirtDonk]

...New question as I didn't want to highjack his post.

But thanks for doing it this way Jimmy!
Although slight hijacks are certainly common and often welcome to a thread with similar issues, you were right that it was best to start your own in this case.
Especially since, as jckkys pointed out, the other guy doesn't even have possession of his truck yet. Like was asked though Jimmy, are you squirting using your accelerator pedal, or are you having to squirt starting fluid or fuel into the carb to get it to fire? Which method makes a huge difference here.

You're right on another count though too. After 21 years it's entirely possible that your carburetor needs to be rebuilt again. Not necessarily of course, but certainly a possibility.
How many miles on it in this time period? Does it sit more than it drives, or is it a daily driver?
With you living in CA, it's not likely you had a major change in fuel makeup, but by any chance is your area going through a change to new E-gas mixes?

Paul