So I glanced at my dump valve and I discovered it’s not connected to anything! Duh!



The question now is how am I supposed to feed it?

There’s a hose from the bellows to a tee. The two remaining tee sections both go to the pump. I’m assuming only one should go to the pump, the other go to the valve. So the pump is incorrectly connected?

 

Vee,

From memory, the bellows pipe would go to the "upright" leg of the "T". One side of the "horizontal" part of the "T" goes to the left of the 2 pump attachments in your pic. The other side of the "T" then goes to the dump valve.

Cheers

Paul

 

Thanks.

So what do I do with the second inlet to the pump? If I pull one off and plug it into the dump valve, I have an unconnected inlet at the pump.

 

Vee
That gizmo in the first photo looks to me like a fast-idle valve, as used, for instance, to speed up the tickover when the aircon is engaged.
It is also used on some 3.6 engines as a fast idle for cold starts.

 

Vee,

I'm not sure that UK cars use the secondary port on the vacuum pump. So perhaps it relates to the air injection apparatus on US AJ16 cars?

I'm attaching some of the Jaguar instructions for retrofitting cruise to an AJ16 car with a pic of a new vacuum pump. It doesn't seem to show or imply that the second port is used. Where is the pipe currently going from that front port on your car?

Hope that helps

Paul

 

Paul,

Can’t thank you enough for that clarification! It seems that the white inlet is left open! Excellent.

Currently there is a hose on there that takes it right back to the tee.

Will report later if this perhaps resuscitates my cruise control!

 

Fixed.

Still no operating cruise.

Ive tested that dump valve. I get a click when I apply 12v.

Ive tester the pump as well.

I’ve replaced the cruise ECM.

Ive check the bellows. It holds vacuum.

Its possible that the spare ECM I borrowed doesn’t work either, but what are the odds....

 

Hi Vee,

You've got the three "control" switches; the main one on the skislope, the brake pedal microswitch and one on the gear selector. All of those need to be functioning correctly. Perhaps worth checking continuity on them? I thought I remember you saying once that you had a JDS diagnostic unit, or did I imagine that? There's a cruise diagnostic routine in the JDS to pinpoint problems.

Good luck

Paul

 

I do indeed have a PDU unit, unfortunately not all the cables....it seems the only useful cable is the OBD2 connector.

It was an FDS2000 unit that I converted over to Jaguar. Not sure I remember seeing a cruise diagnostic option...or were you referring to the SDD/IDS?