Idling Too High

[Cliff Ruggles]

Is the Vacuum Advance adding timing at idle with manifold vacuum?......

[Zach]

Is the Vacuum Advance adding timing at idle with manifold vacuum?......

I quickly checked this one so I could’ve done it wrong but unhooking and plugging the vacuum lines to the vacuum advance causes no change in idle. I could try a different vacuum source and skip the emissions check valve. Think I read somewhere that the check valve emissions equipment on a 77 trans am is timed and acts as ported.

[Zach]

Still haven’t found a solution, there is an oddity that it will run at 800 rpm but I can’t reproduce this and it eventually builds rpm to stick at 1k, I’m wondering if it’s a distributer issue or the vacuum advance is sticking.

Currently fighting below freezing temps, might postpone this until summer.

[Cliff Ruggles]

Check the timing when the problem occurs and make sure it's back to the "base" setting.  Sticking distributor weighst or mechanical advance will cause exactly what you are seeing.....

[Zach]

Check the timing when the problem occurs and make sure it's back to the "base" setting.  Sticking distributor weighst or mechanical advance will cause exactly what you are seeing.....

I believe I solved the issue, early on it was vacuum leaks, timing, and improper tuning. I got the recommendation for a second tach, used a fancy timing light. Seems to be running at factory spec, my dash tach seems to be off by about 300. Makes sense why I’d see <800 sometimes. Carb is idling great, never heard the car at low rpm’s or knew what to compare it too, not very experienced. Appreciate the base plate rebuild, your book I bought helped a lot when rebuilding the main body, huge help Cliff.

Appreciate the help, seems to be solved!

[Cliff Ruggles]

Good news!....