JMPRO

While doing some misc. maintance on my 78 911sc i discovered that the injectors on the right side of the eng. are loose. At the place where they enter the head they can be turned and twisted in the mount ,is this normal?. the car seems to run fine and there are no fuel leaks . someone please let me know , i don't want to do any damage -Jerry

Bill Gregory

You're not going to do any damage, however a loose fuel injector o-ring could possibly let in a small amount of unmetered air, which is not welcome in a CIS system. After 23 years, assuming those are the original injectors and gaskets, the gaskets can get hard. On Monday I'll post an article on how to tune up your CIS fuel system, including how to replace the fuel injectors and fuel injector o-rings, in the event you want to tackle it.

JMPRO

Thanks Bill, I will be checking mon for that info -Jerry

john walkers workshop

the injectors pop into a plastic sleeve that also has it's own o ring. both o rings get real hard over time and don't seal well.

Roland Kunz

Hello

But a drop rubber friendly oil into the gaps. Thee o rings will swell a bit and be thight again.

The O rings on the injectors can be easy replaced. The others on the thermal barriers need much work as the factory looked them with three pounches. If you dont grind them away your new O ring will get scrached during installation.

Those thing are replaced during an engine rebuild.

Grüsse

JMPRO

Thank YOU ALL FOR THE INFO ,I CHANGED THE O-RINGS TODAY AND WOW , WHAT A DIFFERANCE . I MUST HAVE BEEN LEAKING A LOT OF AIR AND LEANING OUT THE ENGINE. you drive it for 23 years and the reduced performance sneaks up on you