High Idle After Distributor Maintenance

[fireant911]

I have pulled my distributor for the recommended cleaning and oiling. Unfortunately, I was not able to break down the entire distributor (I removed the six-fingered spider looking device for those of you that have SC's and this was as far as I was able to get). I oiled down the shaft, rotated the shaft, oiled some more and continued this until I felt confident that some oil made it to the mechanical advance unit.

At this point I reassembled the distributor and installed it back in my car. I 'eye-balled' where my ignition timing was at previously and drove the car to warm it up to its normal operating temperature. I then broke out the timing light to finish the job properly. I plugged both the advance and retard vacuum lines as directed by the plate under the engine lid. I cranked up the car and it idled at around 2,800 rpms. I adjusted the idle speed via the idle adjustment screw and was able to get it down to only 2,400 rpms.

After about one minute the engine settled down to a respectable rpm but as soon as I just barely moved the the distributor to align the timing mark the idle shot back up to 2,400 rpms. Upon reattaching the vacuum lines the idle was at about 400 rpms (which makes sense since I had gone the engine travel with the idle adjustment screw. I bought the idle back to 950 rpms and everything appears to be fine. Why would my idle be so high with the vacuum lines disconnected and plugged - and most importantly, what can I do to correct this situation?

[fireant911]

any ideas???...

[michel richard]

I know you did not go down as far as the advance weights, but could they be sticking ?

[fireant911]

michel,
I suppose that it is possible but I know that I did get some oil down there... The strange thing is that I noticed an immediate different in the way the rev of the engine after I put eveything back together (although I was not able to set the ignition timing to the exact point - it is with 2° of where it should be). The engine accelerated quicker while in the garage and I noticed a difference once I got it out on the road but I am still at a loss on why I experience the high idle with the vacuum lines disconnected and plugged???

[dimps8]

dosen't the vac lines retard the timing at idle until you hit the throttle. It makes sense the revs would climb with the line removed.

[emcon5]

If you advance the timing, the idle speed will increase. Unplugging the vac lines advances the timing.

What you have to do is:

unplug the vac retard
reset the idle speed
set the timing with your timing light.
plug in the vac retard
reset the idle speed.

Another option is to leave the vac lines plugged in, set the timing so full advance is where you want it, and let the idle setting take care of itself. You will probably have to reset it prior to any emissions testing.

Tom