Well I broke down and bought a NEW carb from National Carburetor to replace the BBD I rebuilt.
Mine was having some problems with the idle and needles popping out of the main jets and hanging up. I think it was too much cross matching parts from different BBD's I have laying around.
So when I heard about EMI's $160 BBD I had to try it out.
I ordered one for a 1980 Jeep 258. My engine is really a 76 258 with a 84 Intake and exhaust. Figured no sense getting the one with the stepper motor if I don't need it. And I have a 1980 motor I'm keeping as a spare.
My old carb would idle at 18 inHg @ 800 RPM when it was working otherwise it would kick and stumble dropping to 15-16 inHg.
Doing nothing but bolting on the new carb gave me 19 inHg at 1100 RPM.
After a little tweaking I got it down to 20 inHg @ 800 RPM.
The only trouble was the throttle stuck after installing the carb. The new carb came with a thinner spacer and the original springs would not pull down the throttle at idle. A new spring fixed that all right.
The original idle mixture screws were about 5 turns out with hardly no effect on idle but it was idling high. Dropping the idle down and turning in the screws to about 1-1/2 out turns made it sweet. Mixture was fully adjustable from rich to lean.
No Carter Name here
Bottom of Venturi matches the throttle bore. The Carter BBD does NOT.
Vacuum and idle speed without touching a thing
Top View. I wonder if they really put these on a dyno as the tag says
Total Itme to remove and install the new carb. 31 min...
Result, I'm happy. It runs without worrying if it's going to keep running past the next stop sign.
Need to run a long term test though. See if I'm still happy next month.
I took videos of the whole install if anyone is interested.....