Hey everyone i have a 1968 mustang coupe with a auto 289 2 barrel. autolite 2100 to be exact. the car was running funny after letting it sit after awhile so i got carb rebuilt. now it runs but makes a popping noise and shuts off when i put into drive. i put headers on as well. checked idle screw and set right. what else could it be? i need car fixed by this weekend please any help is good
thanks!

 

whats the choke doing? Is it nearly closed? assuming its an auto choke.

what about vacuum leaks? are all the fittings tight and unused vac ports blocked?

-Gun

 

1) Running funny? You mean like a rough idle when it got hot?
2) What is the RPM at park? Does it fluctuate up and down?
3) Turn on the car in the dark with the hood open, look for any stray sparks from the plug wires.
4) When you put it in drive, does it lurch at all or just pop and die?
5) Make sure the linkage from the accelerator pedal to the carb is tight, also check the kickdown cable to the transmission.

These are just questions I'd need answered without seeing it myself.

 

the choke is closed when off and when running its open...fittings look tight and vacuum block offs are blocked off but then again there is one or two of them i duno if they should be off or connected somewhere.....running funny by there being a pop every prolly 10 seconds idles fine but shuts off after awhile. rpm i dont know because i dont have a rpm gauge on it. when i put it in drive it just pops and dies. linkage from pedal to carb are tight.

 

Please post some pictures of the carb. I need to know what you mean by "one or two vacuum should be off or connected". Assuming a proper rebuild, the installation is in question. Normally, this means a vacuum leak. The popping says lean which usually means vacuum leak. When it is idling and you spray a little carb cleaner around the base of the carb, does the idle go up?

 

ok i will spray around base soon as i get home 2day in the afternoon as well as post pics
thanks!

 

Sounds lean to me ...

the autolite has only one vacuum pickup where you hookup the vacuum advance for the distributor. At the choke housing there is another one where you plumb the heatriser.
To answer the question about the choke: it's operated via heatriser (not electric).
But choke open when warm and running sounds good.

you say you have the curb idle screw (at linkage) set, now adjust the idle mixture screws they're both onder the front of carb). Start with 1 and a half turns out from stop.
when you close them to find stop don't tighten at all that will destroy the needle tip of the screw. just turn in til seated, then 1 and a half turns out

leave it running in park and spray some wd40 at the following places (while running/warm) with all ports on carburator that are open plugged


a) the carb base (basically the whole carb but make sure not to spray into the carb)
b) the intake manifold gaskets (all of them: between intake and carb and between intake and each head)
c) the vacuum line between intake and auto gearbox
d) the vacuum line between the intake and the power brakes (if you have them).

If at any stage the idle changes while you spray WD40 you have got a leak at that line or gasket.
make sure to not spray into the carb as otherwise the test is invalid

 

Make sure you didn't disturb the wire that connects to the coil. Your symptoms sound exactly like when a coil starts to fail. I doubt that your coil failed but the wire could be loose from the carb work. One other thing to try to prove coil is to start the car at night and with a spray bottle , spray misty water on to the coil sides. If the coil arcs then the coil housing is failing. Lack of full coil power will cause your carb to backfire when reved past idle speed. Or when place into drive.

 

im about to go try this stuff out now what wire on coil? the one going to distributor? or those two small ones?

 

The wire that runs to the distributor.