CIS problem: system pressure = control pressure. Both wrong.

[worn]

Wow Tony! Thank you so much. I have learned so much from you on this project. Now hopefully I am closer to the road as well. I know that you have a matched set of calibrrated gauges, so I will be replacing the harbor freight kit right away.
Warren

[worn]

I just checked my photos and notes. FD #925 was in the car. #344 was a spare from ebay that I rebuilt.
Thanks again!

[worn]

I spent time off and on through the summer, fall and into winter until I was ready to throw in the towel. Cleaned out the tank with vinegar (you have to fill up the tank all of the way to keep the metal above the water line form rusting; perhaps inert gas would do). Bought a new fuel pump. Replaced the MSD ignition box (I wanted two so I could carry a spare). Tested spark length and timing. Tony adjusted my WUR and fuel distributor and the control and system numbers were right when installed in the car. Ran compression and leak down tests, checked for spark. Timed the spark as best I could with a cranking engine.

I had avoided changing the mixture set screw because I was afraid of getting lost and adding a mistake to the list of variables. Recall the motor had run for 10 minutes at first attempt - not smoothly but had run. But as there was nothing left, I added more fuel and the motor ran with the richer mixture. At a minimum of 3,000 rpm. OK, that points to a vacuum leak.

I had previously used a smoke machine to look for vacuum leaks and not found much, although there was a wisp of smoke coming from underneath the intake runners. At the time we thought it was stray smoke from the machine, falling down from the insertion point for the tube. A retest though made it clear that the smoke was genuinely coming from an intake leak. A few hours later the airbox was out and a fair sized crack revealed.

Going back, during the rebuild of the motor the intake just sat there getting older. When I first started the car the change in displacement to the 3.2 ss probably called for more fuel. The motor ran lean and slow combustion caused backfires into the intake. I shut the engine down at 10 minutes to clear out exhaust fumes and adjust my aluminum hose to the outside air, on restart the motor made one great backfire, the airbox burst and then I was left working out the problems. During that working out the fuel delivery system was observed to make funny pressure readings and off I went after that hare.

I think that the Bosch K-Jet was so complexly tuned that there are too many places for failure such that running diagnostics for spark, fuel and compression becomes complex. For me a systematic approach eventually uncovered problems, but it was hard to cover all of the bases at once. Add the age of each component together and you can have a situation where intermittent failure of two components can make life unpleasant.

Now a question: Glue the box back to regain sealing? I think this box has already been glued by a previous owner. A pop-off valve is in place and the two halves are joined with adhesive at the seams. Did stock boxes come glued together?
Or. Buy a new airbox? Are they available? I think the tubes coming out of the box for the runners is 333-34 mm in diameter.

Thanks everyone - especially Tony.