ZX TD thinks its permanently cold..

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philhoward

ZX TD thinks its permanently cold..

Post by philhoward »

My new (!) ZX TD thinks its cold all the time - idle speed is from 1050 to 1100 rpm all the time, plus does have that "clatter" noise like an over-advanced diesel. I slackened off the Waxstat cable..and its still there!

I know that on the Lucas pumps (like I have) that it only operates a switch (what a waste!), but have disconnected the wire from the switch and it STILL does it. Should I be shorting this wire to ground instead, or is what it actually controls playing up? Some solenoid, I guess?

Cheers All.
Phil
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Post by Peter.N. »

Are you sure it isn't cold? Does the temperature read normal? Thermostat?
philhoward

Post by philhoward »

Temp reads 90 degrees, and gets there is a very reaonable time...no isues there.
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Post by Peter.N. »

Ah right! Does it have a seperate sensor for the idle control? I am not familier with the ZX, although my wife has one, its never gone wrong! What year is it, does it have electronic engine management? If not, does disconnecting the cable from the pump lever have any effect?
philhoward

Post by philhoward »

It's a 97 (R), doesn't have an ECU (that I can find), and i've slackened the waxstat cable right off (to simulate a warm engine all the time) and its made no difference
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Post by jeremy »

On the front of the pump when you look at it there are 2 devices. One has a rubber pipe going to it - this is the turbo boost overfuelling device - and the other (higher and to your left) is the electromagnetic advance control.

Firstly I'd check that there really is no current going to it - then I'd look at replacing it.

This is not a common problem (not working is - generally due to waxstat) and I don't recall anyone's experiences of dealing with one on here. Hopefully someone more knowledgeable than me will be able to help - as may a diesel specialist or Lucas service centre.

It may well be that it unscrews and can be substituted easily but for all I know bits may fall out or something.

Alternatively some of the 4X4 boards may help as they all seem to tinker with their pumps until they belch black smoke - but I think most recent Land Rovers use Bosch pumps.
jeremy
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Post by AndersDK »

Check the switch area to ensure the mechanism does not hold the switch shortcircuited. The switch itself with spring and wiring is not exactly most reliable ...
The solonoid is activated by the switch connecting to earth - so its quite easy to get a false earth path down there.
With engine stopped & ignition on - you should measure a +12V over the open switch.

Agree with J that this solonoid is not a common part to be replaced. Its always the waxstat in the thermostat housing.
Anders (DK) - '90 BX16Image
philhoward

Post by philhoward »

I've even disconnected the wire from the switch (the waxstat cable is already slack), and theres no difference whatsoever in the idle speed (or the advance - which is what it sounds like). I'll check the wire incase its shorted through a clip (and do the 12V check as well), but looks like it's a first - the solenoid has jammed open!
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