Bring 'Em back Alive Addendum

Bring 'Em back Alive

Addendum

Trying to debug the fuel injection system was an education. It gave me new respect for the engineers who figured this thing out and made it work. If a carburetor (particularly a Weber) is black magic, the Bosch D-Jetronic is sheer voodoo. And finding information about it and its foibles is like trying to figure out hieroglyphics prior to the discovery of the Rosetta Stone.

I was even past Llew's vast Porsche knowledge. Poking around the internet I finally found a couple of papers in places like the Rennlist Porsche forum which went into both theory and the practicality of diagnosis. These were quite helpful, but still lacked the full depth of a factory manual. But such did not exist, or at least I never found one...until after I had gotten the car to a pretty high state of functionality...the level it is at today with perhaps too much timing advance, too rich a mixture, and poor idle in hot weather.

Some time after this and long after the car was, to my satisfaction, “finished” (though I doubt there is any such state for a restored car), my friend Lee Cohee put me in touch with someone who claimed to have a full set of Bosch factory manuals for both the “D” system and the “L” used only on the 1.8 liter cars.

What? Nah...these are made out of unobtanium. And why would a Lotus mechanic have such a beast anyway? But Ken Gray did. He works for Dave Bean...owner of a source place for old Lotus cars and parts, former acquaintance through vintage racing, and local guru in nearby San Andreas. Seems Ken, at some point in his career, had thought he might like to be a specialist on cars using the system, so bought a full set of manuals. He not only loaned them to me, but allowed me to scan the sections applying to the Porsche versions. In doing so I was surprised to learn that the Jetronic was also used by VW, Volvo, Mercedes, and Ford. But I only copied the general material and those parts which applied to Porsche.

I figured others could benefit from this material, and though it took a lot of e mailing back and forth as Bosch tried to locate the actual ownership of the material within the corporation, gained permission to publish my scan on Rennlist and club sites. To my surprise and disappointment, to date I have only managed to get Rennlist to respond, though my post of the manuals there have been viewed almost 800 times to date. But at any rate this material was not available to me while I was trying to get the car to work better.

It was a long a difficult slog. I will print below all the items replaced on the car, and just a glance at the mechanical items will reveal how much of the FI system was worked with, and things still are not perfect. But the car finally was tuned well enough to be considered “complete,” at least mechanically. So off it went, leaving me yet again for a short time, for Charles to do the upholstery.

The result was fantastic...far beyond my wildest hopes. It really looked like it had just left the showroom. Though I had now spent more than twice what I had estimated on the car, I was still just short of being “under water” in terms of value, though I plan never to sell it. I was afraid to remove dash knobs as these are delicate and unavailable (except maybe from Bontempi), and Charles managed to finesse the new material around the controls without removing them...it looks absolutely perfect. As are the newly upholstered door panels, the driver seat cushion and bolster, and the new carpet. I did buy new plush floor mats to protect the latter as otherwise the lower driver position results in quick wear spots.

I ran into one scare after the upholstery was in. The car refused to go into gear and I thought we would have to rip up the center tunnel carpeting to fix the linkage. Fortunately only a set screw accessible from under the car had backed out of the shift rod. There is an indent in the rod so misalignment is impossible and it was an easy fix.

One problem that must be addressed is a leak from where the shift linkage enters the box. There would have been no way for Llew to know this was there as it was only when the car was driven a few times that it began to show up. The fix also appears to be fairly straightforward but at this point, recovering from back surgery, I am not yet able to confidently lie under the car to do so.

I documented all that was done to the car, and that list follows. With the exception of replacement items noted below, the car is entirely original as delivered from the factory.

Mechanical Work

• Custom 140# front springs
  
• Factory upgrade anti-roll bar
  
• New brake rotors
  
• New brake calipers from 2 liter model
  
• New master cylinder
  
• New brake lines
  
• New shift linkage
  
• New throttle cable
  
• New clutch cable
  
• Swapped out tail shifter transmission for side shifter, including new motor brace. The replacement was from a 914-6 and therefore has closer ratio gears than the stock unit. Stock the ratios are 3.09, 1.89, 1.26, .93, and .71. Therefore the “steps” between gears are 1.2, .63, .33, and .22. The new ratios are 3.09, 1.78, 1.22, .93, and .76. Thus the steps are 1.31, .56, .29, and .17, closer in all but between 1^st and 2^nd. The rear end ratio for both is 4.429. The smaller drops between the normal road gear plus the taller ratio in fifth should mean more punch in driving due to staying in the best torque spot of the revs when upshifting. Original tail shift transmission retained
  
• New engine fuel lines
  
• New ignition points and condensor
  
• New fuel pump
  
• New spark plugs and wires
  
• Optima gel cell battery
  
• New Yokahama Avid tires (?)
  
• New Bursch exhaust
  
• New clutch disk
  
• New pressure plate
  
• New Throwout bearing
  
• Refaced flywheel
  
• New fuel injectors
  
• New brake bias valve
  
• Replaced Auxiliary Air Valve
  
• Rebuilt Manifold Pressure Sensor (MPS)
  
• New vacuum lines
  
• New Throttle Position Switch (TPS)
  
• Rebuilt and re-curved distributor
  

Cosmetics

• Body stripped to bare metal
  
• Two stage paint in original factory color, including front and rear trunks
  
• Fiberglas front valance
  
• Removed “hockey puck” front fender lights
  
• New front fender to cowl inserts
  
• New correct Hella Euro turn signal lenses
  
• New door window “squeegee” weatherstripping
  
• New “on body” door weatherstripping using correct OEM German material
  
• New dash material using correct German “waffle weave” material-exact match to original
  
• New driver seat inserts using correct German “waffle weave” material-exact match to original
  
• New driver seat bolsters
  
• New interior carpeting
  
• New correct rear window to engine cover weatherstripping
  
• New front trunk weatherstripping using correct OEM German material
  
• New rear trunk lid bumpers
  
• Painted targa top
  
• Powder painted rocker panels
  
• New polished door sills
  
• Powder painted rear valance
  
• Coverlay dash cap (available but not installed)
  
• New foglight grills
  
• Powder painted intake manifold
  
• Powder painted engine shrouding
  
• Stripped, Rebuilt and powder coated NOS Pedrini wheels (6) as original options for car with new center caps
  

Refresh expenditures total $18,000 (estimate)

Pretty Much as It Looks Today
and as it did some 47 years ago