Hi guys,
After several years of cruise control not working, I bought new bellows as possible cause. Sealed it, cleaned the interior and contacts before that and even installed hose clamps. Cruise control started to work perfectly…speed was OK, braking cancelled it and resume resumed the speed.
But only for 5 miles…back as before… any idea where should I start to check it?
Thanks for any advice,
Cene
Sorry, same topic above…thought it did not go through…
There is a little rubber disc on each solenoid; possibly fell off? Also some had a recall that added a solenoid to the vacuum supply- perhaps something amiss there. You can run straight manifold vacuum to the port on the servo to test. Cable problem?
I’d love to get mine working, I tried putting power right on the solenoids with the engine running and nothing. I think they check out with an ohm meter. Probably valves jammed with deteriorated rubber bits?
Robert, I thought about both issues you pointed out… will check vacuum hoses first. I have read about these rubber discs but I have no clue where they are supposed to be… I guess from inside? When I took old bellows down, nothing felt out…from the outside there is cap on solenoid and little thin filter. Where is supposed to be that rubber disc?
Maybe I should take it out and take a photo…
Thanks,
Cene
Is it possible at all that cruise control would work at least few miles and several on an off and resume function if there are no these rubber seals?
Where exactly those seals are installed?
Cene
Bottom photo, they are on the end of each solenoid plunger, glued onto the plunger. When the plunger extends, the rubber disc covers the port in the housing. If I recall, one solenoid controls venting the bellows, the other controls vacuum applied to the bellows; and the windings share a common. One has to have power (vent side) and the other no power for vacuum to actuate the bellows.
You may want to download Kirby Palm’s book “Experience in a Book” from the XJ-S forum; has a good section on checking out the electronics of the Econocruise system.
Thanks, Robert. Would you be so kind and help me, find the place on the photo. English is not my mother language, so not so easy for me…would you lead me to a place from, say the end of one of yellow lines… would appreciate.
Thank you,
Cene
Asked my 15 years old son…
He explained to me that rubber disc should be on the top of that plunger. On the left solenoid on the tope, between brown and blue wire connector… he is probably right?
Cene
Both sides, of course…is that the right place - top of the plunger, is that correct?
Cene
Just went to test drive…again, cruise control worked for few engages and disengages and resumes and no more.
Took out the bellows, see the photo. I guess the rubber disc is supposed to be on the small metal disc (plunger). I even cannot see if there is rubber ot not…the plunger seems to be extended.
Can I force the plunger down by something, like small screwdriver?
Thanks,
Cene
Yes, the rubber disc should be on the metal disc. The plunger should move freely, if I recall there is a spring that holds them closed (extended). You can try moving both plungers with a small screwdriver.
A WAG from afar. Apply voltage at the bench and see if the solenoids kick…
A bit of lube to encourage free movement when volts are applied…
OK, thanks, Robert.
Cheers, Cene
Yep, I found the procedure. Will try it.
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I downloaded the cruise control ‘manual’ from the earlier Jag-lovers site, Cene - years ago. It may still be there; <wys/wyg://49/http://www.jag-lovers.org/books/xj-s/16-Cruise.html>…it’s 13 pages…
I have very carefully proofread the line - so failure to download is likely that the document is no longer available. It describes test procedures in detail - and did help me…
As Robert says; one valve opens to allow vacuum to the bellows - the other vents bellows to the atmosphere. Both of course controlled by the respective solenoids - which are controlled by the AC amplifier…
Frank
xj6 85 Sov Europe (UK/NZ)
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Frank
xj6 85 Sov Europe (UK/NZ)
Sorry, Cene - for some reason 3/4 of the line disappeared.
I try again; wysiwyg://49/http://www.jag-lovers.org/books/xj-s/16-Cruise.html
Repeat for ‘manual’ input; wysiwyg://49/http://www.jag-lovers.org/books/xj-s/16-Cruise.html
Frank
xj6 85 Sov Europe (UK/NZ)
Cene,
Since you have the bellows out it’s easy to check.
Apply voltage to each one and see if the plunger moves and blow to see if the they open/close and seal properly.
If they do, the bellows part of the system is ok.
The solenoids either work or not.
To me it sounds more like a bad contact/bad cable somewhere, or the module itself, maybe temperature related?
An other thing to check is the stalk switch button, it’s known to cause problems.
It’s very hard to troubleshoot, as there is no way to test it on the bench.
