Hi, I have 3, 1.8 tdci cars in our family, 2 x focus and an Smax. Now the mk2 and Smax start whatever the weather but the Mk1 is a pig in the cold. I have been through all the plug, loom, relay checks on the mk1 to no avail. The mk2 and Smax  glow plug lights stay on for 6 seconds. The mk1, 1 second. I have checked the voltage to the plugs and that goes when the light goes out. My question is what controls the time the power is supplied to the plugs? This is the only other thing left to check and as this is the only difference between all three motors I am assuming it's a fair bet it may be the problem. 😕

8 hours ago, rg1642 said:

I have checked the voltage to the plugs and that goes when the light goes out

Interesting you should say that. On our old Mk1.5 1.8TDCi the light went out after a second but when I checked the voltage on the plugs it stayed on for 5 seconds. I imagine the ECU controls it so maybe yours might be getting a false engine temperature reading from somewhere.

You don't say what mileage your Mk1 has done but on ours, at over 100K, three of the four plugs were shot. Having said that, after I'd replaced them I didn't notice any significant improvement in winter starting.

175000 and all the plugs work ok. I haven't changed the CHTS. Never thought of that. Can't be shot but might be just starting to break down I suppose. The cars nearly had it to be honest but this just annoys me that I can't solve it . Lol 😀