If I needed to test a unit to see if it is a problem, can an L Jet. from another year, or even manufacturer be used? Is the software mapping different, the harness different, etc?

The car I have is a 1984 S with auto trans.

Thougt it might be a good idea to have a backup..

AFARR

 

You need a an L-Jetronic with this P/N 928.618.106.03 or 928.618.106.04.

There is no software mapping, because there is no CPU, these are analog computers. They are 35 pin and only the Porsche model will work.

 

In my experience here on this board, I cannot recall anyone having an L-jet control unit go bad. THey are pretty robust. The S4's and the LH-jet is a different story though. I would suggest you rule out all other possibilities first (unless you can get a loaner).

 

Quote: "I cannot recall anyone having an L-jet control unit go bad"

Thanks--I was beginning to get worried..

Am still going to work on the basic electrical stuff-contacts, checking wiring, Cleaning Grounds, etc.

 

the L-jet units do go bad just not nearly as often as the LH brains. This is a good thing since Porsche no longer makes the brains for the 1980-1984 USA spec cars.

 

Mind the +'s and the -'s when jump starting!

About the only real difference in function that I have been able to discern is that starting with revision 02 ('82), there's an injector pulse output for the mileage meter.

The later revision brains (01, 02, 03, 04) will work in the earlier models, including 1980. Rev. 00 ('80) might have slightly different programming since there's no air pump that year, but my '80 runs fine on a 03 (plugged right in).