I need to adjust the fast idle on my '72 skylark 350-4. I understand about adjusting with the engine warm and set in drive and having the cam follower on the low step of the fast idle cam as stated in my '72 buick manual. The problem I'm having is I can't see the cam follower with the main vacuum diaphragm in the way. is it already in position when the engine is warm? How do I know the cam is in the right position so that I can adjust the fast idle correctly? Thanks, Brad
The fast idle cam will need to be raised to the highest position if the engine is warmed up and choke fully open. Keep in mind that the fast idle speed will be higher fully warmed up than when the engine is cold. How far the choke pull-off unloads the choke also effects fast idle speed on a cold engine. To get ideal settings you will need to correct adjust how far the pull-off(s) unload the choke on a cold start, and the fast idle cam position at the same time. Not really all that difficult, but it may require several cold starts to find the ideal settings.....Cliff
If you want, you can unscrew the vacuum diaphragm and move it out of the way so you can see the fast idle cam. As long as you don't pull the vacuum line off and the engine is fully warm, you should be able to make the adjustment.
Thanks you guys, I'll be working on the carb this weekend. I like the idea of moving the vacuum diaphragm out of the way but keeping it attached. Brad
