My van gets a little accelerated 'boost' when slowing down at a stoplight, why?

Question

I have a 1977 Dodge B200 van. It runs great but whenever I'm slowing down to stop, somewhere between 2-5mph my van gets a little jump of power/acceleration. This happens EVERY time. It's not dangerous, but it is pretty annoying and I'd like to correct any problems with the vehicle.
I would prefer not to take it to a mechanic if it's just something to be done with the carb.

Thanks!

Thanks for the answers! (the first two so far).....

I wish I could get ahold of Ironhand:
You're correct, I upped my idle to stop the stalling at low speeds, only to discover that it was running poorly (and got gross polluter status) because of 1 plug not sparking. I'll turn the idle down.

It runs awesome, but still stalls randomly once in awhile without other symtoms. I changed the plugs and the wires, and tonight I'm changing the distro cap, rotor, and fuel filter.

However, part of getting gross polluter was failing inspection. The paperwork notes say--

Dash Pot is missing (it's a new carb, and I thought dash pots were only for manual transmission...)

Air intake solenoid is disconnected.

I don't understand the second for the life of me, but my engine is easy to access, and everything is in full view from the console area......

I'd like to do this stuff myself, not just to save $$$, but to learn more about how cars (on a simple level) work.

Thanks again so far!

Answer 1

Your DODGE doesn't have a modulator, so don't spend your time looking for it.
It sounds to me like your idle is a bit high, in which case, when the transmission shifts from 2 down to first, the RPM charges a bit, giving you the feeling of acceleration. Try to adjust the idle speed screw down (counter clockwise) by about 50 RPM and try it.

Good Luck

Answer 2

Sounds like the van is shifting down to 1st gear to late. I would try to replace the vacuum control module it is only 10 bucks or so. Also make sure the vacuum line that goes to the intake is in good shape. If you log on to the group below I can send you more help on this matter also other techs can help too.