Hey everyone,

Sounds like a problem with the accelerator pump. What type of carb is it?  Car off. Take the air cleaner off make sure its been running or you know it has fuel in the carb. Pull the accelerator linkage and you should be able to see squirts of fuel coming out into the carb..



"Came too close to dying to stop living now!"

Okay, I'll test that pump. It is a 2100 carburetor. Thanks for help guys. Could the pump have gone bad after only two years though?

The Autolite 2100 and 4100 have several adjustments for the amount of accelerator pump.  The horizontal lever usually has 2 holes for the link.  The vertical lever adjacent to the throttle arm has 4 holes.  Moving the accelerator pump link to the inner hole on the horizontal lever increases the amount of pump shot.  Moving the link to a lower hole on the vertical lever also increases the amount and thus temporarily enriches the fuel mixture off idle.  Try moving the accelerator pump rod toward the richer settings from where it currently is until the flat spot goes away.  You may have to also adjust the initial spark timing too but this should help.  Let us know your results.

Is the carb original to the car? Early model 2100's have a check ball in the pump circuit behind the accelerator pump diaphragm that sometimes develop a flat spot and can cause a hesitation. Easy to spot, you'll see a large screwhead on the carb body right behind the accelerator pump housing. If there's no screw you have a later carb with the red neoprene check valve. If you have the early model you should be able to remove the screw and retrieve the check ball with a small magnet to inspect it. Just something easy to check without a lot of disassembly.

Dan      Kingman Az.      86409

Well, I drove the car today, putting the accelerator pump between selection 1 and 3. (1 is the richest setting right?) It still wants to die out in that one spot. The carburetor is original to the car and does have the screw above the accelerator pump. I have not checked it for flat spots yet. I suppose I'll get my timing light out and see if anything is off. Could my vacuum advance be causing trouble as well? It is original. I tested it before though, sucked into it and it did move the diaphragm.

Yes.  Carburetor parts can die quite quickly and especially where ethanol laden fuels are concerned.  Have you checked the ethanol content?  While 10% ethanol is a problem for carbs, 15% or more ethanol is even more of a problem when it comes to general drivability.  The age of the fuel is also a consideration and especially so if it has ethanol.  Water absorption is a consideration also.

Did you check that the accelerator pump is shooting a nice stream of fuel from the discharge nozzles?  It should do this quite easily.  If you have to move the accelerator arm quickly to get that discharge, then the ball under the screw is suspect.

Lorena, Texas (South of Waco)

Here are a few videos I made of the car running today. The first video shows the car running with the accelerator pump on position #1 and second video of it at #4. I did these videos as a test because I had tried adjusting the idle mixture screws (Before realizing that adjusting these wasn't going to do anything, as these are for IDLE only…lol) I haven't checked timing yet, that's tomorrow, and I haven't pulled the little check ball out yet, but I'll do that soon. (Also, you can barely make it out in the video, but my fuel line going into the carburetor has a big kink in it, I don't know if that might cause any trouble, but the car runs fine for everything except alliterating from a dead stop like noted before)

Okay, and update for today...

Took her out again today, still doing the same thing. If I really punch it she'll move past that dry spot and be fine after that. Seem to accelerate well while at speed. If I'm in reverse and going up an incline, the engine will do the same thing, scary thing there is after it moves past the bogging point, the engine will really let loose and then my driveshaft just bangs the differential into movement. I hear that loud clang of a driveshaft typical when you change from forward to reverse…almost feel like she'll burn out. Gotta be careful though, don't want to shatter my diff.