Vacuum Gauge
 

Where should I connect my real Vacuum Gage on my 1986 560 SL?

Thanks, Jack

"Real" vacuum gauge? Are you speaking of a supplementary gauge to determine engine vacuum as opposed to the "Economy" gauge which is mounted in the instrument cluster?

The best spot would be at the rear of the intake manifold where there is an existing line. You could just disconnect the ninety degree rubber coupling at the firewall for the Economy gauge and use that line.

HI Yes Real Vacuum Gauge. I will Look for that Connector, The vacuum Gauge on the Instrument cluster is in the correct position All the way to the left.

My Issue is 900RPM Idle at start up. Takes quite a while to settle a bit lower.

Suggestions are for temp sensor replacement Coolant and or Engine .

Is there a way to test these?

Thanks, Jack

Your question is a little confusing. I understand that you want to install a “real” vacuum gauge as opposed to the economy gauge. The advantage of having a vacuum gauge or economy gauge is to drive with the vacuum gauge at the highest level possible. The higher the vacuum level equates to better fuel economy.

Hi Brian, You are speaking of the one that comes out of the manifold has the 90 degree rubber coupling then it goes to a greyish plastic tube that runs across the firewall above the Brake vacuum Booster and goes to this Y connector and that goes through the firewall to the Instrument cluster?

Looks like an easier connection there? Jack

My main issue is that I have a 900RPM idle and has a acceleration hesitation until about 5 minutes of warming up. Still has hesitation at most speeds.

Checked the Idle control valve seems to be working Has 4.6v at the connector. Some folks say to take it apart and clean it Others are into various temp sensors or an O2. Any suggestions> Jack

Hi All

The purpose is to diagnose my engine Idle issue. Not for a permanent installation. I do not believe that there is a vacuum leak. My smoke test did not show one and the Vacuum gauge on the instrument cluster does go all the way to the left. It seems that a vacuum gauge could show other issues .

Thanks, Jack