The problem with the Frequency Valve was the computer. It was the one that came with the car and has worked and not worked over the years. It was not the correct one anyway. It was for a VW 4 cylinder. I installed a correct one and the FV vibrates. Still am unsure that it is passing gas.
Here is my shot glass measurements of fuel distribution cylinders 1 - 6. This is at idle for enough time to fill the baby bottles to the amount needed for shot glass measurements. Obviously, the fuel distributor is in trouble.
First thing is to get the 2 year old gas out of the tank and check for debris. Pulled the hose off the back of the pressure pump and let the lift pump suck the tank dry into a 16 gallon storage container. No trash but old gas.
After the shot glass fuel test I had to break the Fuel Distributor open. It appears that the commercial rebuilder used JB Weld as the sealing product. It was a mess in there but no obvious failure. O rings on the center hub were 'rusty' but there was no indication that would have caused the uneven fuel distribution. Two of the small O rings on the oblong ports were broken but again that wouldn't seem like a cause of such uneven distribution. The very fine vertical splits within the ports did not appear blocked when inspected by shining a very strong light through them. Each had a sharp, unobstructed light image. That is the first place I expected to find blockage.
The nozzles on the fuel pressure volume regulators all were dead level with the cast iron surface. The springs and caps are evenly the 5.2-3mm specified in the rebuild YouTube video.
The nozzle's passages apparently do not go straight through. Even the finest wire I could come up with, from a fine wire wheel, did not pass through. Much smaller than the opening but not, apparently directly connected to the outside. That is where I expected to find another obstruction or other issues with the fuel volume.
I placed the upper half on a paper towel and blew air through the injector ports down into the chamber of the FD. Got spots of trash at each port.
Obviously, the seal is going to be based on a sealant applied to the iron top and bottom mating with the stainless steel shim. That is the question for the night . . . what sealant? I have read Indian Head Shellac, and red thread locker. Never heard of JB Weld before.
What say the experts?
The JB Weld was really a mess to clean up.
BEFORE:
AFTER:
Note the rough surface of the cast iron face. No signs of precision machining to ensure no leaks. This unit had to have come from Bosch like that.
The answer to the flange sealant is
Loctite 515. Specified exactly for steel to steel seal with an one hour work time and 24 hour full pressure set time.
My best effort at a very thin layer of sealant.
Probably too much. There is a very small hole in the stainless steel shim that feeds pressure but not much gas to the CPR. I had great concern about blocking that hole.
Got it all together and pumped another couple gallons of Chevron Techron through the tank, pumps, filter, fuel distributor and injectors.
Here are the results:
At idle:
At about 50% throttle:
At full throttle:
Compared to pre rebuild that is wonderful.