75ZT Community

Interesting situation Sunday morning.

Switched on the FBH (Fuel burning heater.) by remote, and loaded up the car.
Heater ran for around 7 minutes and we were ready to go, so I tried to start. Engine turned over and sort of fired but would not run. I did notice that the glowplug light was not on. Bear in mind it had been round -12C overnight. Eventually, after loads of cranking, it ran. It had been hesitant the morning before, again having run the FBH for only a few minutes.

Now I'd not seen any problems with the glowlpugs before, so I wondered what might be the cause. My theory is that the water was warm enough for the control to decide glowplugs weren't needed. But in fact the heat hadn't got through to the cylinders.

Tried it this morning without running the FBH, and it was -9 overnight so very similar. Glowplug lamp came on, instant start.

So the moral of the story is, ensure you start the FBH with enough time for it to get PROPERLY warm, or don't run it at all. It may fool the system into not running the glowplugs.

Do we know what triggers the glow plugs? My light always comes on, even in mid summer?
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It will base it on coolant temperature I would think. Does it always come on, even if the engine is warm?

Maybe I do have a problem then?

Duncan wrote:Does it always come on, even if the engine is warm?

No, if the engine is still warm, it won't light up at all. Depending on temperature it will be a different length of time as well.

But I don't know which sensor is accountable for that.

No the light doesn't come on when the engine is hot in the 75, but the one in my ZX always comes on, hot or cold..

It is easy on my ZX to light the glow plugs, it just needs a 10 sec feed to any plug from the battery. I imagine you would get the same results on the 75...
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James.uk wrote:

It is easy on my ZX to light the glow plugs, it just needs a 10 sec feed to any plug from the battery. I imagine you would get the same results on the 75...
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It would on the 75 if you could get at them to do it.

Ran the heater for 15 minutes this morning. No plugs, but started fine since the engine was actually warm enough.