back fire on air filter

[kamotezee]

hi guy! i purchase 280sl. Before i buy the car is stock about almost a year.so i start to repurbish it. i change breaker points, spark plugs, coil, filters most common parts in tuning a car. the problem is every time rev the engine theres a little backfire on air cleaner. im just 25 years old im not familiar with this kind of fuel system. need help from the expert...

[ja17]

Hello kamotezee, welcome !

Backfiring through the intake is normally caused by a lean fuel  situation. First do some research on this site. Go through the linkage tour. Make sure the main fuel filter is clear. If you do not find any issues you may need to take a fuel volume and pressure check.

Learn the "split linkage test" so you can diagnose engine mixture problems.

You may need to check the barometric compensator since in can cause  lean running if it fails.

Lastly make adjustments to richen the fuel mixture at the injection pump.

Ask plenty of questions and we can help you l learn!

[kamotezee]

tnx for the info sir. it solve the backfire on the intake, but there is little rough idle, i will try tune it again, why the fuel/air adjustment screw on my injection pump is not turning when i pushing it.