Go Back  Jaguar Forums - Jaguar Enthusiasts Forum > Jaguar Models ( Classics ) > XJ40 ( XJ81 )
Reload this Page >

1994 jaguar vander plas xj6 4.0l vacuum schematic

XJ40 ( XJ81 ) 1986 - 1994

1994 jaguar vander plas xj6 4.0l vacuum schematic

 
  #1  
Old 04-22-2019, 09:47 PM
Junior Member
Thread Starter
Join Date: Apr 2019
Location: Phoenix
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Default 1994 jaguar vander plas xj6 4.0l vacuum schematic





Does anyone know what this part is. Itwas located in the engine compartment on the drivers side on the fender by the horn . It has something to do with the vacuum.
 
  #2  
Old 04-23-2019, 05:58 AM
Partick the Cat's Avatar
Senior Member
Join Date: Apr 2013
Location: Gloucestershire, England
Posts: 923
Received 240 Likes on 185 Posts
Default

Hi Alec

I'm afraid you've posted in the wrong subforum, this is for XJ s from 2003 to 09.

Sorry, but offhand I'm not sure what the correct subforum is for '94.

Dave
 
The following users liked this post:
Don B (04-23-2019)
  #3  
Old 04-23-2019, 08:24 AM
Join Date: Feb 2014
Location: The Beautiful Mid-South, U.S.A.
Posts: 16,518
Received 7,519 Likes on 4,201 Posts
Default

Hi Alec,

Welcome to the Jaguar Forums! It's great to have you with us.

I have moved your post from the forum for the X350 to the forum for the XJ40, which is the Jaguar factory project code for your 1994 VDP.

The part in your photos is the Cruise Control Dump Valve. When you press on the brake pedal, it opens to release all the vacuum from the system to immediately disable cruise. It's a critical safety component.

You can easily test the valve. It's normal condition is open, so with no power applied you can blow through it. When you apply 12 volts to the terminals, the valve should close and seal completely so you can no longer blow through it. Failure of the dump valve is a common cause of an inoperative cruise control system.

Please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheeers,

Don
 

Last edited by Don B; 04-23-2019 at 08:28 AM.
  #4  
Old 04-23-2019, 08:56 PM
Junior Member
Thread Starter
Join Date: Apr 2019
Location: Phoenix
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Don B View Post
Hi Alec,

Welcome to the Jaguar Forums! It's great to have you with us.

I have moved your post from the forum for the X350 to the forum for the XJ40, which is the Jaguar factory project code for your 1994 VDP.

The part in your photos is the Cruise Control Dump Valve. When you press on the brake pedal, it opens to release all the vacuum from the system to immediately disable cruise. It's a critical safety component.

You can easily test the valve. It's normal condition is open, so with no power applied you can blow through it. When you apply 12 volts to the terminals, the valve should close and seal completely so you can no longer blow through it. Failure of the dump valve is a common cause of an inoperative cruise control system.

Please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheeers,

Don
Thank you very much. I did a smoke test on my vacuum system and smoke came out of it. My question is, does it stay open when cruise control is off or is suppose to be closed ?
 
  #5  
Old 04-23-2019, 10:32 PM
Join Date: Feb 2014
Location: The Beautiful Mid-South, U.S.A.
Posts: 16,518
Received 7,519 Likes on 4,201 Posts
Default

Originally Posted by alectempleton View Post
Thank you very much. I did a smoke test on my vacuum system and smoke came out of it. My question is, does it stay open when cruise control is off or is suppose to be closed ?
The short answer is that I don't know for sure, but a simple test would be to measure the voltage at the dump valve electrical connector with the engine running (and cruise control off, of course). If you have 12 volts at the connector, the dump valve should be closed. You would think the dump valve should be closed anytime the engine is running but the brake switch is not activated. Otherwise, the dump valve would constitute a constant vacuum leak.

Cheers,

Don
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Frank Houghton
New Member Area - Intro a MUST
7
11-06-2018 04:59 PM
Nickie
XJ6 & XJ12 Series I, II & III
2
10-13-2016 11:36 PM
rickysjag
New Member Area - Intro a MUST
3
04-15-2011 09:52 PM
wrangler
XJ XJ6 / XJR6 ( X300 )
1
03-30-2009 11:28 AM
jemetz49
New Member Area - Intro a MUST
0
12-27-2007 10:21 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Quick Reply: 1994 jaguar vander plas xj6 4.0l vacuum schematic


Advertising
Featured Sponsors
Vendor Directory

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: