|
Set your dwell (if you have points) and your ignition timing first. You set the floats so that is good. I assume your fuel pressure is set at 3.5psi. You next need to return all the air bypass screws (the ones next to the idle mixture screws) back in all the way and re-synchronize the cylinders (with an air meter) with the linkage disconnected from the carbs. This will eliminate the possibility that your problem isn't that you are bypassing too much air (around the butterflies) causing the high idle. If you find that you have to use a lot of air bypass on a single cylinder this is an indication that something could be off wrong with the shaft adjustment but that is another issue. If you still cannot get the idle adjustment screw to engage with the throttle arm then you have a problem with the carb and it may need to be rebuilt. Leaking shafts could cause an air leak or the butterflies could be not aligned allowing air into some cylinders and not others. This is what would cause you to need a lot of bypass air on some cylinders and not others.
Carbs don't generally go out of tune it is usually the other way round, the motor goes out of tune or the carbs were set up on a poorly tuned motor and then when you fix the motor problem the carbs need to be re-tuned to now match the properly tuned motor.
If I had to guess I would venture that you have too much bypass air causing the high idle.
__________________
09 Cayenne GTS: GTS red, race car tow vehicle
86 Porsche Carrera, GP White- E Class PCA Club Race Car
71 Porsche 911T Targa, Silver, Sport seats, 2.7RS spec motor.
90 Porsche 928 S4 w/ 37K miles Grand Prix White/ Cashmere
73 Karmann Ghia Cabriolet, Black, 1776 Turbo, 250hp
Last edited by turbochad; 11-12-2009 at 09:02 PM..
|