My plans to rebuild the 17085001 were successful, I think. I got it rebuilt, installed it on the truck, and saw the vacuum ports are a little different. No big deal, just need to run some new hose to reach. And then I realize I cannot remove the connector/pin/whatever you call it, from the 17080513 for the throttle cable to connect to. So off to the parts store for vacuum line and hopefully carburetor linkage parts. No linkage parts. So I dug out my other old carbs in hope of stealing it from one of those. No avail. My only option at this point is order parts for the 17085001, or just rebuild the 17080513, so rebuilt the 17080513 Saturday night, got on a roll and finished around midnight.
Installed it yesterday, after a few cranks it fired right up but the bench setting for the fast idle was extremely high. Adjusted that down and let it run to warm up so I could do the fine adjusting. I noticed some of the same symptoms I observed before the rebuild; Idle mixture screws were basically non-functional. A little more tweaking and I was able to get them to show some signs of working as the engine went from rocking at idle to smooth enough to set a beer on it and not have it get shaken up.
Was going to test drive it, and when I pressed the brake pedal I hear a hissing sound. I checked the back connection on the carb for the booster vacuum and it was tight. Try the brakes again and hisssssss as the pedal slowly goes to the floor. I thought it was the booster. Off to the parts store and they asked which system I am running. I have no clue and nothing on the truck tells me. I later find out it is a JB7 brake system. I also acquired a schematic for my cruise control, which is a Cruise Master. When I installed the carb I ran a new line from the Tee on the back of the manifold to the transducer on the firewall, and this in affect, energized the cruise control system with vacuum. The schematics I saw show a vacuum line going into the cab and connecting to a vacuum release valve on the brake pedal. At lunch I had the GF push the brake pedal and it hissed. I cut the new line I added and plugged it and had her hit the brake again. No hissing and the pedal held firm. That vacuum release valve or vacuum line going into the cab being faulty instead of the booster sure saves me money in parts. Glad it was something simple.
So I got to drive it, and the cold start/fast idle is good, the cold running is much improved, performance is better with no more stumbling, but now the vacuum leak is gone I have to readjust the carb and the timing. The exhaust has a funny smell to it, kinda like a sweet smell. Not sure if that is a lean smell or a rich smell. The gas is good.
Once I get it all dialed in I can see how the secondaries operate. When I got on it at lunch it took off really well but I doubt the secondaries were kicking in. I may have the air valve spring a little too tight. Is there anything else I should look at while I at?
