My 72 has a 350 with a Carter AFB competition carb. On moderate to heavy acceleration, it stalls and sometimes backfires through the carb (bad for the chrome air cleaner cover). It does it in neutral also. I should know this but I've been in the EFI world too long.

you might pull the distributor cap and rotor and check the advance weights/pins/springs etc... make sure everything is free and not gummed up.

just a possibility, hope i helped ;)

Thanks, I'll get on it tomorrow.

I have the same problem? But i have HEI and I don't know what to do either.

it could possibly be a loose/worn timing chain/gears.

one way to check... rotate dampner, line up marks. note VERY closely the position of the dist rotor... now rotate the engine the OPPOSITE direction, line up marks and recheck rotor position... the engine rotates, pulls the slack out of the chain... rotated the other way the slack is on the other side of the gear... it'd show on rotor position if chain/gears were/are bad...


just another thing ta check...

always do the basic/easiest first (also the things that cost no $$$ ta check) ;)

Do you have vacuum advance (a metal canister attached to the distributor)? If so where on the carb/manifold does the hose to the canister hook up? Do you have a timing light? Have you had a chance to check ignition timing.

Finally timing and carburetion mimic each other; so you have to check to see if you are going lean because of such things as a screw in the secondary throttle linkage, or little to no gas being squirted into the carb as the throttle blades open ( do not look into the throttle with the engine still running unless you are tired of your eyebrows, and want really sore, burning eyes).

Big Dave

Vaccuum advance on the distributor is connected to a fitting on the intake manifold. There is a second hose that runs from the same fitting down behind the block somewhere. I need some daylight to check the routing on that one. I'm going to replace the cap, rotor and plugs this weekend anyway. They look OK but not great. Just bought the car so I think I'll start fresh with new vaccuum hoses too. Maybe I get off cheap and easy.

If that doesn't do it, what do you guys suggest next?

If the engine stalls and pops in neutral, it could be a carb problem.That means the engine is running rough even when there is no load on it. Is the choke working correctly. Check the fuel pressure also . Could be a faulty fuel pump.If everything checks out with the fuel system ,check the plug wires with a ohms tester .Then check the ignition coil. Auto-Zone will check it for free.

Second hose goes down to tranny to tell it you have your foot planted on the gas pedal. Poping through carb can be caused by a sticking valve (exhaust hangs open and ignites incoming manifold charge), It can be timing related as well (spark plug fires before valve closes but not likely, as car would hardly run this way with distributor 180° out of sync), it can be caused by a lean condition where the fuel/air charge is stycheometric and any ignition source sets it off. Cross fires from a carbon fouled distributor cap, or from induced charges in paralell plug wires, or shorts in plug wires. Lots of possibilities but few concrete solutions. Do not buy stuff until you have checked out what you have first.

It gets to be real expensive really quickly with a replacent until the problem is diagnosed rational (I have an "electrician" that uses that approach to fixing my water pump for irrigation. Wife calls him while I'm off playing around and I come home to a thousand dollar repair that he has not quite figured out, having replaced my contactor, and timers, and starting caps and relays. I then pointed out the dead lizard in the points for the pressue switch that when removed allows the pump to run).

Big Dave

You might want to check the acceleator pump in the carb.

The accelerator pump gives you the initial fuel squirt to get you going. If the pump fails, you don't get that initial squirt and the engine can die, sputter, back fires, etc. If your pump is bad and you go easy on the throttle it may work just fine, because the engine will build the vaccum it needs to drawl the fuel in.

I check the accelerator pump by removing the air filter and looking into the carb, hit the throttle and look to see if you the fuel spray. If you get spray its good, if not thats your problem.

Make sure the engine is off. It's pretty dangerous to look into a carb when its running..incase of back fire.

This may not be the problem, but it is easy enough to rule out.

I hope this helps.

Kevin

its going lean accel pump or vacume leak. spray carb cleaner etc in throat of carb while jabbing throttle . ..i bet the problem goes away.... accelpump or vacume leak

I had a friend one time a few years ago checking the carb at night with a lighter.:noway: Poof no eyebrows and very red face. He quit drinking for a while or at-least till his eyebrows grew back.