Rochester Quadrajet rebuild

[billyjack]

Here are a few more thoughts: Vacuum leaks-Are all unused vacuum ports sealed? You can spray some carb cleaner around the carb with the engine running. If the idle changes, you've found a leak. Primary metering rod operation-Stick a small screwdriver down the bowl vent and try to lightly depress the primary metering rod hanger. You should feel the spring tension as you depress the hanger. I've seen improperly positioned float bowl gaskets that kept the metering rods bottomed, causing a lean primary side. Pump shot-Look down the primaries and cycle the pump 2-3 times. Do you have a good stream of fuel shooting into the bores?
BTW, I didn't check out the carb number you posted yet, but most of the 75 and later numbers are good cores. About a 70-72 jet with 36-40 rods should be a good combo for a mild street engine. I wouldn't mess with the APT. While it's a good fine tuning aid, I believe you have a more basic problem to solve, based on your description.

Bill

 

[RITTER]

There aren't any unused vaccum ports on this carb :? unusual I know, I have the large front one connected to a PCV, the only other one in the front is connected to the vaccum advance and the large threaded port in the rear has a fitting in it which adapts to my brake booster vaccum hose, those are the only ports on the entire carburetor.

I will check the primary metering rods tomorrow and check the fuel flow into the bores as well

 

[Bonnewagon]

I ran that carb # against this site http://www.newagemetal.com/ and it shows that it has #63 jets and # 40 rods. There's your problem, those jets are not good for a healthy 73' 350. I would recalibrate that carb with at least # 71 jets and keep the #40 rods which are very rich and will give you great takeoff power. If you need more overall power then go up jet sizes to a # 74 max, but you may need to drop down the rods to like #50 then. That carb is from a 1978 CK-10-20-30, G-20-30, or P-20-30, probably with a tiny motor.

 

[RITTER]

Well, how about this ... the carburetor I removed from the engine was a
17085210
2494 HKP
would these jets and rods be worth swapping in my
17058213
:?: