No Vacuum

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Aug 7, 2011 | 01:45 AM

Cracker289

Thread Starter

Cargo Master

Joined: Jul 2003

Posts: 2,715

Likes: 20

From: Four Oaks, NC

No Vacuum

I was setting my timing earlier and while messing with it I realized I could not feel any vacuum at the hose which connects to the distributor. I pulled the other end off the carb, and could not feel any vacuum there either.

What are some things that could cause this? The engine does idle, but very weakly. The carb is a motorcraft 2100.

Aug 7, 2011 | 08:34 AM

ilovemy60ford

Senior User

Joined: Apr 2004

Posts: 167

Likes: 0

The vacuum advance on the dizzy is usually connected to ported vacuum. A ported vacuum source will not have any vacuum at idle. It's likely normal.

Aug 7, 2011 | 08:55 AM

tmcalavy

Posting Guru

Joined: Jun 1999

Posts: 1,083

Likes: 1

Set your timing with the vac hose off the distributor and plugged. Then make sure the dwell (point gap) is good. Then set the curb idle speed, should be around 550 to 650 depending on whether it is a manual or auto tranny. Then connect a vacuum gauge or MityVac to manifold vacuum port...with truck running at idle you should get a steady 18 to 20 Hg of vacuum on the gauge. Adjust your carb mixture settings in or out to steady the vacuum reading on the gauge and get it in the 18-20 range. Then install the air cleaner and recheck/adjust the curb idle speed to get it around 550 to 650 rpm. Google "reading a vacuum gauge" for more info...too much to list here.