Hard to start

Stalling or stumbling when you press the accelerator pedal is a symptom of a worn or mis-adjusted accelerator pump. We never replaced the entire carburetor for that. In the past we could buy just that part, but today you might have to buy a compete rebuild kit to get it. Even those are very inexpensive.

What do you have to do to get the engine started? Once running, how does it run?

I am not Mr. Know it all,

I explain much better when I have "hands on" (and can "catch" other things that might need attention)

In the following link I did not cover adjusting an accelerator pump and other tweaks that might be necessary, which CARADIODOC mentioned above.

The link I am sending was to a Jeep CJ, Most of the carb/ timing adjusting is pretty much the same for our Wonderful U.S.A made pre- 1986 carburetor vehicles. The only differences being the 'looks' and 'locations' of the stuff I am explaining to the Jeep Guy (you should get a Jeep, this would be much easier on you!)

If it ran decent before- let's not mess with timing (if needed) till it runs decent.

Mainly if you get anything out of it,

Look at possible Vacuum Leaks (which could have contributed to the whole problem all along)

Adjusting or initial adjustments to make it start running better in order to tweak things better.

The use of meters/ gauges that gets things right/ not winging it by ear!

Here is the link.

https://www.2carpros.com/questions/jeep-cj7-1985-jeep-cj7-stalls-when-hot

The best-us thing going is a factory service manual, next being any repair manual for the specific vehicle, You tube might aid you also if you need real time explanations and video.

Return here with good news or if you have more questions,either way keep us (me/ Doc/ everybody else) posted!

The Medic

"Pressing lightly" on the accelerator pedal reminds me of a problem I ran into in the late 80s. We have become accustomed to, (or grown up with), electronic fuel injection. Engine Computers look at coolant and air temperature to calculate how much of a priming squirt to command from each fuel injector when we start the engine. In the days of carburetors, it was standard practice to pump the accelerator pedal a certain amount to create that priming pulse, and that came from the accelerator pump. Every car was different and developed its own "personality". Owners became familiar with the best starting procedures for their car.

When I worked for a Sears Auto Center in the '80s, one of my jobs was installing a really nice aftermarket cruise control system. I did that for a woman on the '80 Chevy Citation she had just bought. That was on a Friday. She returned on Monday, furious that I had damaged her car. She had to crank and crank to get it to start, but she admitted that once it was running, it ran fine. When the boss asked her to show him how she started the engine, her procedure did not include pressing the accelerator pedal. Turns out, it had been real warm during the summer, and like many cars of that era, the float was set so high in the float bowl, no additional priming was needed to get the engine started. Three days later the temperature had dropped to the 40s, and surprise, her lack of following the recommended procedure resulted in a crank / no-start. The boss flipped her sun visor down and showed her the starting instructions right there in front of her. She blamed the problem on me or the cruise control, but it could just as easily have been blamed on making too many right-hand turns, driving too long after dark, hitting a pot hole, or buying gas at the wrong gas station.

You may be running into something similar. A weak or dead accelerator pump will not give the needed amount of fuel for a priming pulse, and it will cause the stumble or hesitation when accelerating. When you open the throttle blade, air flow increases instantly because it's real light. Fuel is much heavier, so it takes some time to build up momentum and get flowing. That's the cause of the lean stumble. The accelerator pump pushes some fuel into the air stream to overcome the delay.

If you installed a used carburetor that has been sitting on a shelf for a while, it's a real good bet the rubber diaphragm in the accelerator pump has dried out and has become ineffective.

Have you actually checked for spark? How about looking for the two nice streams of fuel squirting in when you work the throttle by hand?

One vacuum leak that is often overlooked on Fords is the metal tube that runs from the air filter housing, down to and through the right exhaust manifold, then up to the automatic choke housing. That pipe often rusts out below the manifold.

Spark would be nice to know!

With the squirtage of starter juice in there and a "no start" (rather no "wants to start"), sorta sounds like No Spark!

Here's an EZ tester to use, see my link

http://shop.advanceautoparts.com/p/lisle-inlline-spark-tester-20610/22984543-P?searchTerm=spark+tester

Do you have points or is this stock electronic ignition?

What about a cheap digital voltmeter (Harbor Freight has 'em for about $5)?

Many possibilities for no spark, the voltmeter would maybe narrow things down quickly.

Keep it up Doc, not trying to steal no glory, just getting more info for the next responses!

The Medic

Electronic ignition? Hahaha! For decades Chrysler was the leader in innovations that actually benefited car owners. They developed the "AC generator" for use in 1960 models, and copyrighted the term "alternator". GM and Ford copied the design four and five years later. Chrysler developed the first electronic voltage regulator, (1970), and the first electronic ignition, (1972 on Dodges, and 1973 on Chryslers and Plymouths). GM and Ford caught up in their '76 models. Chrysler had the first computerized engine controls, (1977), lock-up torque converter, (1977), anti-lock brakes, (1969), and first air bags, (late '80s). AMC actually had the first electronic ignition control module in 1970 but it still used breaker points, so it didn't address the problem of rubbing block wear and the resulting ignition timing change and increase in emissions. (That increase in emissions was so tiny that it was only important to politicians).

I had to stick this history lesson in here because I just finished a conversation about all the tricks some manufacturers incorporate into their cars today that benefit the them at the huge expense to their customers. I'd rather be driving a 1972 anything over any newer model when it comes to having to diagnose and repair it. Technology is cool but in too many cases we're outpacing our need for it.

What are you testing? What "points" are you referring to? What kind of "tester"? What is the connection between a test light and vacuum hoses?

I've seen those testers but never used one, so I don't know what "normal" is, but if you have some spark, everything in the system is working. WEAK spark can be caused by a partially-shorted ignition coil, which you replaced already, and by a defective condenser. The condenser blocks the 12 volts DC from being shorted to ground while providing the needed path to ground for the coil's primary AC current to flow. With a missing / defective / open condenser, the primary AC current has to go backward through the circuitry and to the battery. That severely limits its efficiency and results in reduced spark voltage, possibly reduced to the point it can't jump the spark plug's gap. Even if it does jump the gap in a spark gap-type tester, or across a plug you're watching, higher voltage is needed when you add compression in the cylinder. That compression makes it harder for the spark to occur.