Octavia difficult starting from cold

[Inspector Beetle]

Octavia 90bhp 2002 (52)..
Q.Glow plug light only on for less than one second.. Changed glow plugs, still difficult to start. Is this a problem with the ECU??

Any advice appreciated..
Howard...

[VAGMAN54]

possible coolant temp sensor......a code read should pick that up or disconnect the coolant temp to see if it pulls the heater plugs in for longer.............

[Inspector Beetle]

Codes read today. No faults logged. Suggested I try a new coolant sensor.. Will keep posted as to results.. Electrician said that this Tdi engine should start straight away (as did my Passat) and could not find any thing wrong!!
Ideas on a postcard please!!!
Howard

[Inspector Beetle]

Thanks Vagman & Crasher for the replies.. I will be changing the sensor and will let you know if it works!
H...

[greg123]

The glow plug symbol should light for 1 second as an indication that the engine ECU is powered up, this is not an indication of glow. The glow plug will stay on longer than 1 second to indicate glow, but only if the exterior temperature is 9c or below. It won't stay on for any meaningful time unless the temperature is freezing or below and a decent tdi will still start well then (albeit with a little shudder/smoke) with no operating glow plugs.

The most common cause of poor start on these by far in cold weather is retarded static injection timing.

Temp sensor, 109 relay, anti shudder valve, slow starter motor, ecu map hole (for hot starting only) are all issues but I'd like to see a full fault diagnosis printout and also an oscilloscope of the static injection timing in basic settings before thinking further.

Greg.

[Inspector Beetle]

Thanks for that inf. I have since my last post changed the coolant sensor and the starting has improved. As you point out it smokes a bit and shudders slightly but then its away..I am thinking of having it remapped to 110bhp to help with towing..
Thanks again... Howard...