vacuum level measurement

yo,
I have some tests for you, but none address that method, ok?

Read this;
Overview; see pages 59-61 in Ford EEC IV Operation & Testing Overview; PowerPoint Presentation; "...
If da Engine Coolant Temperature Sensor (ECT) is Below 50 degrees F, then TAB is grounded & sends air to atmosphere;
If Between 50 and 190 Degrees F, Bypass Valve sends air to Diverter and to Manifold;
If Over 190 Degrees F, it is in closed loop & Air goes to Catalytic Converter;
Bypass when at idle, Wide Open Throttle (WOT), and with failing Oxygen Sensor.
The fastest way to see if vehicle is in open loop is to see where the air is going;to Atmosphere or Manifold it is in Closed Loop, provided the thermactor system is working..."
Source: by Ryan M (Fireguy50) at powershow.com

Some Functional Tests by Chilton via miesk5 at FSB

yo Buddy!
thanks for the reply PM on that Slovak Bronco site.
Vacuum Reservoir (VRESER); it stores excess vacuum to prevent rapid fluctuations and sudden drops in a vacuum signal, such as during acceleration. It services the EGR & Air Injection (AIR), Secondary Air Injection Systems
It prevents rapid fluctuations or sudden drops in a vacuum signal such as those seen during an acceleration period. When charged initially with 51-67 kPa (15-20 in-Hg) vacuum, vacuum loss shall not exceed 2 kPa (.5 in-Hg) in 60 seconds. If it does, replace the reservoir..."


EGR includes EVR (EGR)
AIR sys includes:
Thermactor Air Bypass (TAB) & Thermactor Air Diverter (TAD) Solenoids;

It prevents rapid fluctuations or sudden drops in a vacuum signal such as those seen during an acceleration period. When charged initially with 51-67 kPa (15-20 in-Hg) vacuum, vacuum loss shall not exceed 2 kPa (.5 in-Hg) in 60 seconds. If it does, replace the reservoir

This is from the VECI Label for a 90 5.8

Vehicle Emission Control Information (VECI) Decal; Contains Vacuum Diagram & Calibration Parts List for 88 & UP. On-Line for Free at Ford. Click "Quick Guides" in left panel; Scroll to & CLICK VECI Labels "Provides Vehicle Emission Control Information (VECI) and a related calibration parts list." Enter applicable info (need to know your Calibration number from your B-pillar sticker). Vacuum Diagram is the same as the one on the core support or hood or air filter cover. Suggest Right Clicking this Hot Link & Open in New Window
Source: by Ford @http://www.motorcraftservice.com


RESERVOIR ASSY., (EGR Vacuum) Ford pn is D5TZ 9E453-A

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There is also a Vacuum Tank (plastic ball type) for the heater/air cond./defroster vac ckt; it's source is off the intake manifold vacuum "tree"

Vacuum Tank (plastic ball type) Location & Diagram in 80-86 & 92-96; "...80-91 similar, except 87-early 88 w/factory air; The 80-86 vacuum tank is a plastic ball on the R wheelwell..."
Source: by Steve83 (Steve, That dirty old truck) at SuperMotors.net

The tree Looks like this

pic by joelb23

yo, of course, I overwrote the HVAC Vac Tank pic;


The Ford pn changes hourly...lol
I saw a neat Chromed replacement at Advance Auto last year in the chrome dome section,, it was smaller but was under $10.00

Dorman has em for GM trucks and looks sim for about $8.00


This one is oversized for the Brakes $49.99
Ships from and sold by Speed Unlimited Performance.

for the EGR/AIR sys tank, SigEpBlue made his own...
Ford pn for later MY is D5TZ9E453A $37.10