Ferrari Mailing List: Replacing fuel injectors

[Rick Lindsay (rolindsay]

Hello Friends,

I have a question or two regarding the process of replacing K-Jetronic 
injectors.

My car uses an early K-Jetronic system, without lambda and without the vacuum 
limiting device fitted to U.S. Spec. cars.  It also uses the earlier style of 
injector retainers which are screwed into the inlet runners.  Here's a look at 
one, http://www.aubard.us/Mondial/HPIM1336.JPG .  And as anyone who has removed 
spark plugs from an aluminum head knows, there is a chance for galling the 
aluminum as I (attempt to) unscrew the 25 year old steel retainers!  Since 
these seem to be original steel injectors, they are most likely original 
equipment and have been in place for 25 years!

The recommended removal method is to disconnect the plumbing then unscrew the 
retainer with a deep socket on the injector.  I anticipate a good cleaning 
followed by a soak of PT Blaster as a thread lubricant before attempting to 
unscrew the retainers.  Any of you done this?  Can you recommend a better 
methodology?  Perhaps a light rap of a hammer on the steel bit by placing a 
larger socket over the injector; something to just loosen any corrosion between 
the threads and the runner?

The next issue becomes the installation of new injectors.  As you probably 
know, the new injectors are made of brass, a softer metal.  Newer cars used 
hard rubber plugs rather than steel retainers.  My concern is about later 
removal of the injectors with only the soft brass injector flats to unscrew the 
steel retainer.   So again, I ask for your experience. Should I just lube the 
steel threads with a copper-based anti-seize, not over tighten and not worry?  
Or can/should I update the retainers to the rubber plugs?  Will they work in 
threaded holes?  Or perhaps should I mill a slot in the steel retainer tops and 
later fabricate a special tool to help unscrew them?

Your experienced advice is appreciated.

regards,

rick
'83 Mondial QV
'79 308GTB
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