Fire breathing Carb!!

My car has been sitting for a few weeks and I went to fire it up, started rough as usual, gave it some gas to keep it idling high and then it launched fire out of the top of the carb (Carter AFB 4bbl, on a mild 302). I immediately killed the engine, and the fire stayed in the carb for a few seconds. What causes this, and how do I fix it? I plan on rebuilding the carb soon anyways, just so I can get more familiar with it, and try and solve the rough starting. Nothing damaged, but enough to make me immediately figure out where the closest extuingisher was.

 

Check the tightness on your Accelerator(Sp) Pump,my bro had that happen saturday at the track it cost me a shrt.

 

Your timing may be a bit to advanced. Check it. On second thought, check and recheck your plugwires to ensure proper firing order as well.

 

I'll check the firing order and timing again, but I set both of those awhile ago, and have never had this problem.

 

ewww

I still say it is timing related.... Pull the distrib and check the gear for wear.

Put a timing light on number 1# and see if the timing is jumping around.

 

The gear is good, I'll throw a light on it next time I work on it and see whats up. Could moisture in the intake possibly cause this problem?

 

What are you getting at here??? lol

 

There is a hole cut in my hood to clear the aircleaner. I had that hole covered, and it either ripped off, or someone removed it. The carb was still covered, but we had some pretty heavy rain, and a small amount of water could have entered.

 

I doubt that would cause the fire. Run the piss out of it and see if it acts better.

 

That's my usual solution!

 

lean backfire...over rich condition/adv timing...Sticking intake valve.Water in the intake will cause the lean condition.It will cause an open intake valve to rust and stick in its guide momentarily...Long enough the have a dragon on your intake...Closest fire extinguisher should be in the passenger compartment of the car...Good luck!!

 

Next payday a fire extinguisher will be going in the car for sure. Thanks for the help.

 

i say it was a lean misfire. a combination of the motor being cold and the accelorator pump being out of adjustment or the diapram on the plunger may be hardened causing a lean moment when you put press on the throttle. what happens is a lean air fuel mixture burns really slow so there is still burning gas in the cylinder when the intake valve opens again. this lights the charge in the intake manifold and results in fire coming out the throat of the carb. if you left it running the vaccume will usually suck up the fire and put it out.

 

Damn that was my guess. Rusty intake valve. Beat me again.

 

Next time it does that get the marshmellows out and make smores. Turn a bad situation into something good!