Dodge Qjet idle mixture screw question

[76PW200]

Hi Cliff!

Its been a couple of years since I sent you my first question and now that I have the engine running I have a couple more for ya. First, when I went to adjust the idle mixture screws on my carb (17087175) I found a broken metal sleeve of some sort around the RH screw. It just came out with the adjustment tool when I drew the tool out. I assume it is part of the seal that was drilled out when the carb was rebuilt but I don't know for sure. Is it important or can I throw the piece away? One other thing I noticed is that I can crank the mixture screws in until they stop and it doesn't seem to effect the idle mixture at all. The afr doesn't change, the idle quality doesn't change nor does the rpm. The afr sits around 12.9-13.2 according to my gauge at idle. I can crank them way out too and nothing seems to happen. I seem to recall they should have a noticeable effect but that was a long time ago and another Qjet. Any idea what is going on here?

[qjetsrule]

2 things I can think of, 1: the idle tubes are plugged and have to be cleaned or replaced, 2: you have the throttle plates open too far and it's running off the transition slot, maybe even part of the main venture (look for nozzle drip in the primary venturi). the idle tubes have small holes and can easily clog. good luck

[Cliff Ruggles]

Later model q-jets were very limited for idle fuel and often have very tiny holes under the mixture screws.  I've also seen many of the later carburetors where the mixture screws don't fully seat.  Try removing the springs from the screws and see if you can get some control of the idle A/F ratio. 

It's also possible that there is just enough transfer slot exposed at idle that the engine is getting plenty of idle fuel with the mixture screws all the way in.  Combine this with tiny holes under the screws and you'll have little to no change in idle quality when adjusting them.......Cliff