Think my '81 backfired today - but not sure.
Is this common? Right after fueling it up to start without a working cold start.
Mine backfired all the time since the fuel distributor had issues. I wouldn't worry too much about it.
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
Last edited by 320iAman; 02-13-2019 at 01:00 PM.
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?
Always FUN TO DRIVE - Build Thread & Tech info - 79 320/6 track car build thread -- Videos of track car -Adam in car Auto-x video - Start-up video - 4/2011 Adam's TOP BMW time San Diego BMWCCA - 4-5-15 Dyno break-in run new M20B25 - Exhaust Thread - Link
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
Backfires are solvable, most of the time too much fuel
Randy
Last edited by 320iAman; 02-14-2019 at 03:12 PM.
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.
Always FUN TO DRIVE - Build Thread & Tech info - 79 320/6 track car build thread -- Videos of track car -Adam in car Auto-x video - Start-up video - 4/2011 Adam's TOP BMW time San Diego BMWCCA - 4-5-15 Dyno break-in run new M20B25 - Exhaust Thread - Link
Forgot it's not a diesel.
Always FUN TO DRIVE - Build Thread & Tech info - 79 320/6 track car build thread -- Videos of track car -Adam in car Auto-x video - Start-up video - 4/2011 Adam's TOP BMW time San Diego BMWCCA - 4-5-15 Dyno break-in run new M20B25 - Exhaust Thread - Link
pumping the gas is a outdated procedure requirement of carburetors, doing so sets the high idle throttle seat, closes the choke plate to reduce air intake and pumps additional fuel directly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.
Last edited by Tom D; 02-16-2019 at 02:21 PM.
Tom D
77 e21 - m42
88 e30m3
04 330 dinan3
84 r1000rt
02 r1150rs
all of them gray
14 f800gsa - red headed stepchild!
If the mix is too lean, it can pop out the exhaust too. And especially if valves are too tight as Randy mentioned.
Last edited by epmedia; 02-16-2019 at 06:03 PM.
Tbd
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