67 one barrel hesitation please help

[Anonymous]

My dad just bought a 67 mustang with the legendary 200 staright six and it is all original car with 105,000 miles. Anyways we tuned the car up(plugs,wires,dist cap, rotor, points, etc. We checked the timing and set the carb back to baseline air/fuel mixture at idle. The engine runs smooth and has good power but when your at a stop light and you get on it to get moving it hesitates almost like it wants to die then picks right up and never acts up until the next dead stop. Now my dad found this carb that somone makes that they say fixes all the problems associated with this one barrel(the hesitation,surging, and also supposed to get better gas mileage and pwoer). ANyways to get down to is there any modifications that we can do to the carb to eliminate the hesitation, or anybody know what we could be worng inside the carb???? Any help would be appreciative, im a diesel mechanic and my me and my dad have always played with old cars but we just dont know what to do with this one. Thanks for any help. I am going to get the name of the company tom that makes that carb.

The motor is still setup for lead gas. If that helps anything.

 

[Mercury Mike]

Do this:
Pull the air cleaner, and pull the throttle right at the carburetor. Do you feel a hesitation when you do that? If not, move on to step 2:

Step 2: Follow the throttle bar along the firewall, and then pull the kickdown lever. Do you get hesitation when you do that? If so, watch the lever as you pull it. It might be opening up the throttle a little bit, and then letting the throttle close again reall quick, then reopening it. If you have a low top speed, this would account for this as well. You might need to lengthen your kickdown cable, readjust it, and tighten down the 2 7/16 bolts on the bracket to the kickdown lever.

Just a thought. =)

Edit: Pony Carburetors the company you're looking at?

 

[CZLN6]

Howdy ao67:

And welcome to this Forum.

The Carb company you are looking for is named Pony Carburetors, Inc. They are located in Las Cruces, NM The Phone # is 1.888.280.4630. They make a very good product, albeit a bit on the pricy side.

I'm guessing your stock Autolite 1100 has a weak accelerator pump. This is not uncommon with these carbs. A rebuild kit is cheap. A rebuild is easy and usually lasts several years.

To check, remove the air cleaner, with good lighting, peer down the carb and work the throttle linkage. You should see an evident stream of raw gas being injected into the venturi. If you do look elsewhere. If you don't you're at least identified the source of your problem.

A rebuild kit is about $25. Last I checked, a Pony Carb 1100 is over $300. You decide.

You didn't give your location or Transmission type. That info would be helpful too.

Adios, David

 

[Anonymous]

does the raw stream of gas indicate a weak accelerator pump or a good one and we did rebuild the carb. Am i checking while running at idle or just pushing the accelerator. SHe has the 3 speed transmission which i think is the c4 automatic right?? How long do you normally lengthen the transmission rod to elmimante the problem just to get an idea if thats what i find wrong with it. Thanks for your help.

 

[Gene Fiore]

A good stream means the accelerator pump is in good working order. Check it with the engine off and just move the throttle open and look inside the top of the carb while doing that. If you don't see any gas squirting down the carb then the accelerator pump is not working.

 

[Mercury Mike]

You have to lenthen the rod as far as you need to for it to downshift. At WOT, the kickdown rod needs to be out as far as you can pull it. Disconnect the spring at the tranny so you don't have to pull hard, and see how far you need it to go. Then make the cable connect to the rod while the accelerator pedal is all the way pressed. Basically, you need it to pull the cable all the way out when you press the pedal all the way down. I sound ridiculously redundant.

 

[mkgcars]

Accel pump: You want to make sure that as you move the throttle the accel pump rod is contacting the accel pump diaphragm and moving it - that there isn't any slack.

Other considerations:
Whats the idle at in park? If it's below 600-625 then it may be too low when you're in drive. I think the spec is something like 550-575 in drive w/lights on (so alternator is under load). Want to do this when the car is warmed up, so cold idle isn't effecting etc.

While the jet size shouldn't have so much to do with low idle hesitation I always felt mine drove a lot better when I increased to a size 67. If yours is below a 64 then you may want to hunt down a size 66 or 67. There is a guy on ebay who sells them for $5.


Curious: Does the carb have an anti-stall dashpot on the other side of the carb? An adjustment of this may come into play - although as your accel pump is giving a good shot, this setting is probably not effecting things. The anti-stall dashpots are designed for automatics, but a lot of times people have gotten rebuilt carbs without them.

good luck, let us know how it turns out.
Matt

PS: My car had same issues as well. For me the accel pump had slack, jet was probably too small (a 54 I think - but an earlier carb had 59 and wasn't much better).

 

[Anonymous]

well me and dad finally got a chance to look at it and i pulled the air cleaner and pulled the throttle and pretty much as soon as it started moving it started squirting a good stream of gas, so i believe me accel pump is good and there isn't much slack in it. Now tom we are gonna check the kickdown cable but from a glance it looks like there is a lot of slack in her. But i aint messed with these setups much at all so i dont know what it is supposed to look like. But me and my dad have heard from alot of guys that these stock carbs were notorious for this problem and surging and that you can't fix them but form what you guys are syaing i sthat you can. I know that when we got the stang it was surging bad at idle and after we tuned her up and rebuilt the carb she quit doing it.
But anyways hopefully the kickdown is whats holding her back.
Thanks