Hi Peeps,
Can anybody offer advice on the following fault.
Went to start my ZX turbo diesel this morning, and got NO dash glow plug light. It did start but roughly.
Later after driving it (engine warm), I went to start it again and the glow light illuminated for 30 seconds. After that the car started 1st turn.
This evening went to start it again (engine cold) and yet again no light. engine started okay.
250 miles later filled up with fuel and the glow plug light stayed on again for 30 seconds (engine hot).
Its all arse about face.
To me it looks like the heater solenoid, but could the two temperature sensors on the thermostat housing have anything to do with it?
Any ideas?
ZX Glow plug light
Moderator: RichardW
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blueboy2001
- Posts: 423
- Joined: 29 Jan 2003, 04:16
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Thanx,
Mines just in front of the relay box, in front of the battery.
As I said it looks to be the relay timer, however the two temperature sensors on the thermostat housing seem to provide an input to the timer. One has two wires, and the other has one. Just wondered what each of these two do in relation to the heating cycle.
Totally confused as to why the glow light stays on when the engines hot and doesn't even illuminate when its cold. I would have thought it would have failed on or off. Thats why I wondered what the sensors are for, as the engines temperature is governing how long the glow light illuminates?
All i know is its wiggly amps, and I hate wiggly amps!!!
Mines just in front of the relay box, in front of the battery.
As I said it looks to be the relay timer, however the two temperature sensors on the thermostat housing seem to provide an input to the timer. One has two wires, and the other has one. Just wondered what each of these two do in relation to the heating cycle.
Totally confused as to why the glow light stays on when the engines hot and doesn't even illuminate when its cold. I would have thought it would have failed on or off. Thats why I wondered what the sensors are for, as the engines temperature is governing how long the glow light illuminates?
All i know is its wiggly amps, and I hate wiggly amps!!!
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by alaws</i>
....the two temperature sensors on the thermostat housing seem to provide an input to the timer. One has two wires, and the other has one. Just wondered what each of these two do in relation to the heating cycle.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
On my 1994 ZX TD the temperature sensors that you mention have coloured plugs, Blue & Green, the Green being the one that controls the Glow plug relay.
I think the Blue one is the control for the temperature gauge in the instrument panel.
When you start the engine on a TD from COLD the glow plugs stay on for approx. 3 minutes this is to aid smooth running & I believe is also something to do with emission control.
If you start the engine when it’s warm (coolant temperature 60 degrees or above, denoted by the Green plugged sensor) the glow plugs only stay on for approx. 15 seconds.
Cars after 94, (not sure when exactly) also had the addition of a micro-switch mounted on the fuel pump that denoted throttle position. If this switch was opened for a set time this would also cancel the 3 minute glow plug period.
Obviously if the Green sensor isn’t working the glow plugs will remain on for the full 3 minutes regardless of the coolant temperature, unless your car has the micro-switch mentioned above.
In my findings these sensors don’t effect the time the dashboard glow light stays on for, I’m not sure what exactly controls this.
I don’t think these sensors will be your problem, as when my Green sensor wasn’t working my dashboard glow light behaved as normal, but at least you now know what they do.
Hope this helps you a little in finding your problem.
Regards Tel.
....the two temperature sensors on the thermostat housing seem to provide an input to the timer. One has two wires, and the other has one. Just wondered what each of these two do in relation to the heating cycle.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
On my 1994 ZX TD the temperature sensors that you mention have coloured plugs, Blue & Green, the Green being the one that controls the Glow plug relay.
I think the Blue one is the control for the temperature gauge in the instrument panel.
When you start the engine on a TD from COLD the glow plugs stay on for approx. 3 minutes this is to aid smooth running & I believe is also something to do with emission control.
If you start the engine when it’s warm (coolant temperature 60 degrees or above, denoted by the Green plugged sensor) the glow plugs only stay on for approx. 15 seconds.
Cars after 94, (not sure when exactly) also had the addition of a micro-switch mounted on the fuel pump that denoted throttle position. If this switch was opened for a set time this would also cancel the 3 minute glow plug period.
Obviously if the Green sensor isn’t working the glow plugs will remain on for the full 3 minutes regardless of the coolant temperature, unless your car has the micro-switch mentioned above.
In my findings these sensors don’t effect the time the dashboard glow light stays on for, I’m not sure what exactly controls this.
I don’t think these sensors will be your problem, as when my Green sensor wasn’t working my dashboard glow light behaved as normal, but at least you now know what they do.
Hope this helps you a little in finding your problem.
Regards Tel.
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blueboy2001
- Posts: 423
- Joined: 29 Jan 2003, 04:16
- Location:
- My Cars:
Hi,
Forgot to mention in my post above, regardless if the engine is cold or warm if you switch the ignition on but don’t start the engine the glow plugs will stay on for approx. 15 seconds.
As blueboy advised the simplest way to test how long the plugs are remaining on for is by means of a test lamp.
Connect one of the wires from the test lamp to the link wire that joins the glow plugs together & the other wire to the negative of the battery.
Switch ignition on but don’t start the car, G-plugs should remain on for approx. 15 seconds.
Start car from cold, G-plugs should remain on for approx. 3 minutes.
Start car from warm (coolant temperature 60 degrees or above) G-plugs should remain on for approx. 15 seconds.
The above times are how long the G-plugs remain on, on my car 1994 ZX TD, the times & the way the G-plugs operate may be different on earlier or later cars, I’m not sure.
Regards
Forgot to mention in my post above, regardless if the engine is cold or warm if you switch the ignition on but don’t start the engine the glow plugs will stay on for approx. 15 seconds.
As blueboy advised the simplest way to test how long the plugs are remaining on for is by means of a test lamp.
Connect one of the wires from the test lamp to the link wire that joins the glow plugs together & the other wire to the negative of the battery.
Switch ignition on but don’t start the car, G-plugs should remain on for approx. 15 seconds.
Start car from cold, G-plugs should remain on for approx. 3 minutes.
Start car from warm (coolant temperature 60 degrees or above) G-plugs should remain on for approx. 15 seconds.
The above times are how long the G-plugs remain on, on my car 1994 ZX TD, the times & the way the G-plugs operate may be different on earlier or later cars, I’m not sure.
Regards
I've had time now to check the glow cycle.
The glow plugs are heating up, but its the light sequencing that is wrong.
ie - when cold there is no glow plug light.
when hot the light stays on for 30 secs unless key is turned.
Does anybody know whether there is anything else in the light cct between the glow timer and the dashboard connection?
The glow plugs are heating up, but its the light sequencing that is wrong.
ie - when cold there is no glow plug light.
when hot the light stays on for 30 secs unless key is turned.
Does anybody know whether there is anything else in the light cct between the glow timer and the dashboard connection?
The glow plug light output is NOT taken from the feed to the glow plugs.
In the timer circuit is an elaborate electronic circuit to determine the light ouput timing - separately from the plug feed output. The circuit determines how long the lamp should glow to signal you not starting engine too early.
Wether the engine temp sensor has influence on this - I donno. It does not do so on my n/a BX.
It's not uncommon to see mod's where the lamp feed has been moved to the plug feed - but this will give you an annoying lamp on for long time at cold starts.
I suspect your glow plug timer is Mickey Mouse - unless you're a wizzard on electronics - it's a replacement.
In the timer circuit is an elaborate electronic circuit to determine the light ouput timing - separately from the plug feed output. The circuit determines how long the lamp should glow to signal you not starting engine too early.
Wether the engine temp sensor has influence on this - I donno. It does not do so on my n/a BX.
It's not uncommon to see mod's where the lamp feed has been moved to the plug feed - but this will give you an annoying lamp on for long time at cold starts.
I suspect your glow plug timer is Mickey Mouse - unless you're a wizzard on electronics - it's a replacement.
I've noticed that GSF sell 3 types of glow plug heater timers, 2 for the standard diesel and 1 for the TD.
I was thinking of taking the one out of my wifes standard diesel to verify this was the fault, but does anybody know whether they are compatible?
(I don't want to damage hers as that would hurt the old wallet)
I was thinking of taking the one out of my wifes standard diesel to verify this was the fault, but does anybody know whether they are compatible?
(I don't want to damage hers as that would hurt the old wallet)
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Dave Burns
- Posts: 1915
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- Location: United Kingdom
- My Cars:
- x 2
No the turbo and non turbo glow relays are not 100% compatible, I know that non turbo plugs will stuff a turbo relay after a short while, I don't know what happens (if anything) the other way round though.
I think post glow switching off when the engine has not been started is connected to the tahco, in the wiring diagram a point is made of showing interconection between the tacho and the glow light, I can't see there being any other reason for this.
If disconecting the tdc sensor prevents post glow when the engine is running then this would seem to be the case, if not, where does the running signal come from, or is it another not very smart system whereby if the ignition switch has gone through its full travel, it is merely assumed the engine must have been started and is running.
Dave
I think post glow switching off when the engine has not been started is connected to the tahco, in the wiring diagram a point is made of showing interconection between the tacho and the glow light, I can't see there being any other reason for this.
If disconecting the tdc sensor prevents post glow when the engine is running then this would seem to be the case, if not, where does the running signal come from, or is it another not very smart system whereby if the ignition switch has gone through its full travel, it is merely assumed the engine must have been started and is running.
Dave
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Jon
Don't fit a standard diesel glow plug controller, it could short the loom (I've heard of this happen)
The one on your ZX TD will probably be a Bosch, there will be a number on it ending "005" or "009", they can only be replaced like for like. Most TD's have the "009" (IE don't fit an 005 to a car with an 009 and vice versa)
BTW very late non Turbo diesels also employ post heat style glow plugs to help meet emissions laws. In fact, the "post heat" glowplug Beru 909MJ or GN013 is now supplied at a Citroen Dealer even if you wanted a set of glows for an old BX 19D, the old Beru 636MJ (non post heat type has been superceded by Citroen), and the later glows work fine in the earlier cars. NOT the other way round though!!
The one on your ZX TD will probably be a Bosch, there will be a number on it ending "005" or "009", they can only be replaced like for like. Most TD's have the "009" (IE don't fit an 005 to a car with an 009 and vice versa)
BTW very late non Turbo diesels also employ post heat style glow plugs to help meet emissions laws. In fact, the "post heat" glowplug Beru 909MJ or GN013 is now supplied at a Citroen Dealer even if you wanted a set of glows for an old BX 19D, the old Beru 636MJ (non post heat type has been superceded by Citroen), and the later glows work fine in the earlier cars. NOT the other way round though!!
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Dave Burns</i>
....where does the running signal come from, or is it another not very smart system whereby if the ignition switch has gone through its full travel, it is merely assumed the engine must have been started and is running.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
I'm also not sure what tells the system that the engine is running, could it not be something as simple as a voltage from the Alternator when the engine is running?
That said the connection between the tacho and the glow light seems suspicious though.
Tel
....where does the running signal come from, or is it another not very smart system whereby if the ignition switch has gone through its full travel, it is merely assumed the engine must have been started and is running.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
I'm also not sure what tells the system that the engine is running, could it not be something as simple as a voltage from the Alternator when the engine is running?
That said the connection between the tacho and the glow light seems suspicious though.
Tel
It's the activation of the starter motor that stops timing the glow light.
Try briefly turn the key against the starter position - then the glow light extinguish instantly. If the engine is cold - then the plugs will continue it's determined timing though - only disrupted if the key is turned completely off.
A sample schematic (no engine temp sensor incorporated) shown for the XM :
http://citroeny.cz/servis/xmser/elektro ... diesel.jpg
Try briefly turn the key against the starter position - then the glow light extinguish instantly. If the engine is cold - then the plugs will continue it's determined timing though - only disrupted if the key is turned completely off.
A sample schematic (no engine temp sensor incorporated) shown for the XM :
http://citroeny.cz/servis/xmser/elektro ... diesel.jpg