Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Can vacuum and mechanical advance curve tuning help my lopey cam bucking issue?
View Single Post
  #50 (permalink)  
Old 11-03-2012, 10:00 PM
bentwings's Avatar
bentwings bentwings is offline
Last photo:
Join Date: May 2002
Location: St.Paul, Minn
Age: 75
Posts: 2,157
Wiki Edits: 0

Thanks: 3
Thanked 97 Times in 83 Posts
Well It was only 30 deg today when I left the shop. The car started right maybe 2-3 rev of the starter and it was running. Gotta love the mini starter.

Once the motor was warmed up I noted that the AFR was about .5 richer than it had been. I think what is happening is that the vac adv is setting the mixture off sooner and more optimum. This allows less throttle pedal (opening) and puts the throttle blades in a different location on the transfer slot...and a different AFR. What ever ...the car ran just great. I drove about 30 miles the long way to the breakfast and there was no lean surge like there was a couple weeks ago. After breakfast..couple hours it still was only 30 deg but the car started right up. I drove around a little then stopped and slowed the idle down a couple hundred rpm. Now the blades are tight in the bores so that's as far as I can go.

It's amazing that a simple change like this can smooth things out. I'm glad I elected to only change the vac adv then go after other items.

Next on the list is to richen up the idle feed restrictions one step (4 jets) to tweek the just off idle mixture. I think it needs to be a little closer to 14.7 rather than the 15.6-15.8 that it is right now. I'll try and do that tomorrow then later in the week I have a good 100 mile trip planned to check mpg for the last time this year.
Reply With Quote