Re: Source for lifters/valves?

[walter@quattro.corp.inmet.com (Walter Meares)]

> I'm not trying to give you a hard time, but are sure it's the valves and
> not the fuel injectors ticking ?  I ran into this with my wifes 88 528ea
> the ticking sounded like valves, but closer inspection with a big
> screwdriver used as a stethoscope revealed the lifters were fine but the 
> injectors are noisy as hell!
> 
> My 89 100 also has a ticking that can only be heard with the hood open
> though......
> 

Injectors that "click" are used in pulsed injection systems (e.g. Bosche 
L-Jetronic and its descendants).  In this type of system, a computer (digital 
in newer systems, analog in older ones) figures out how long to open the
injector to dispense the correct amount of fuel for the engine's air demand.

Audi uses K-jet systems, which use a constant injection spray.  The injector
is a valve that pops open at any fuel pressure above about 35psi.  The amount
of fuel dispensed is determined by changing the size of the metering passages
in the fuel distributer, and by adjusting pressures in the system.  These
type of injectors don't click, they are open all the time the engine runs.

> Just a thought.....
> 
> Mike (53.20 apiece for electronic injectors.....6 in the bimmer :-(  )  L.
> 

Ouch.  But notice how the total reaches around $300.  But it reminds of my
theory of Audi parts pricing:

inconsequential part	$20
important part		$200
major part		$2000
critical part		--call your salesman, trade-in time--

Walter


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Walter Meares		Intermetrics, Inc.	walter@inmet.inmet.com
Information Systems	733 Concord Ave		Cambridge MA 02138
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