carb on fire- how bad is this?

Been lurking here a long time- thanks for all of the education! I'm fixing up a '69 Ford pickup that's been sitting for 7 months. I finally got it started, but the motor cuts out badly when I rev it up- but it idles fine. New points, rotor, cap, coil, plugs and wires- all double-checked. I sprayed carb cleaner in the carb, which made a minor improvement. I had already replaced the throttle pump(?) in the carb because it was rotted. Today, I replaced the dirty fuel filter and the carb had flames coming out of it while I was trying to start it. I put the fire out with a light "puff" of my fire extinguisher. This happened two more times before I realized I might get blown up! Should I try to start it again later, or is this a sign that I need to rebuild the carb? ---- Thanks!

Reply to
Erik
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Or the PCV valve is stuck open and needs replacement (or the hose that goes to it)

Reply to
pete selby

How does this give you fire in the carb?

Reply to
Man_In_A_Black_Hat

Reply to
Mike Walsh

Double check that the plug wires are all going to the proper plugs. Also you might lightly spray the wires with water with the engine running to see if there is any crossfire due to bad insulation.

Reply to
null_pointer

its bad if the fire estingusher was the white power stuff, corosive and near impossible to get out of nooks and cranies with eyeballing the cleaning. Halon is good but doubt it was used since its so expensive to buy. for all quotes there is an equally opposite quote

Reply to
Askari

If you just had a few small puffs of flame, it could be that the carb is just a bit too rich and is igniting. If you get a steady flame, either rebuild it or make sure to carry a good supply of hot dogs and marshmallows with you at all times. And be prepared to paint your hood until you just pull the carb and rebuild it. Never knew Fords did this, the old GM Quadrajet was notorious for fires.

Reply to
L0nD0t.$t0we11

Rich mixtures don't cause backfiring, lean mixtures do, along with retarded timing or valvetrain problems among other things. As usual, "wrong" information is worse than "no" information. Bob

That's a really stupid sig line.

Reply to
Bob

Get the timing and firing order right.. Have you checked the timing chain? If all that checks out, look for cam/ valve problems. A wildly fluctuating vacuum gauge on an intake port is an indicator of valve train wear.

Reply to
TOLYN9

Thanks for all of your help. I bought a timing light and a dwell/tach meter and it's running great! Someone at the auto parts store told me you don't have to reset the timing after changing the points. I should have asked that question here in this forum first! Yes, I used a dry chemical extinguisher, but it seems to be okay even though I'm sure a little bit of powder got in the carb. Thanks again for all of your help!!!!

Reply to
Erik

I guess it was exagerated about the white powder fire extinguisher, I used it once it a kitchen and all was white but maybe its not that corrosive. Its is sodium carbonate or sodium bicarbonate which one is baking powder.

Reply to
David Askari

Anytime the mixture goes excessively lean you get the opportunity for a backfire. I'm not sure the exact mechanism (probably flame-over during the intake/exhaust valve overlap) but I do know that an excessively lean mixture will ALWAYS cause backfiring. A stuck-open PCV valve or other vacuum leak causes a lean mixture.

Reply to
Steve

the white power I seen comes either as sodium carbonate or sodium bi-carbonate which one is baking powder as I read on the box. Yea, its the cleanup that suck,s. Brake fluid is probably worst. On the other hand, the best rust proofing (under car)for salt is oil and even better when it gets thick.

Reply to
David Askari

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