How possible is a backfire?

[mcgee]

Think my '81 backfired today - but not sure.

Is this common? Right after fueling it up to start without a working cold start.

[Thecatmilton]

Mine backfired all the time since the fuel distributor had issues. I wouldn't worry too much about it.

[320iAman]

At Start up-Engine firing out of Timing,valves out of adjustment, Leak in the air intake, Clogged Air Filter--exhaust valve is slightly open and combustion takes place--too much fuel generally--when the car is running a misfire in a cylinder can be caused by fuel injector dripping + spraying instead of just spraying.

Randy

[OLD MAN]

Just a reminder that back firing can blow off vac lines.

Do not step on gas, open the throttle when you start it first time.


Cold or warm?

This is new did not do it here?

[jaredmac11]

First and only backfire I had was due to fuel delivery issues and it blew the boot right off. Scared me half to death and the boot went flying

[320iAman]

Backfires are solvable, most of the time too much fuel

Randy

[mcgee]

I pumped gas on cold start on a cold evening. Hasn't happened since. All the rubber stayed in place and it still idles the same.

[OLD MAN]

I pumped gas on cold start on a cold evening. Hasn't happened since. All the rubber stayed in place and it still idles the same.

I pumped gas? not sure what you mean?

pushing gas paddle only lets more air in.

[mcgee]

Forgot it's not a diesel.

[OLD MAN]

Forgot it's not a diesel.

What no black smoke screens? LOL

[Tom D]

pumping the gas is a outdated procedure requirement of carburetors, doing so sets the high idle throttle seat, closes the choke plate to reduce air intake and pumps additional fuel directly into the carb's throat.

fuel injection, starting with the Kjet that our cars use, does not require nor should the gas pedal be pumped before or while starting the engine.

[epmedia]

If the mix is too lean, it can pop out the exhaust too. And especially if valves are too tight as Randy mentioned.