Reluctant to start, glow plug light on for 1 sec - 1.9tdi

[Winchweight]

Reluctant to start although battery turns over strongly. Fuel smell present and will start eventually. Glow plug light briefly illuminates.

My guess glow plug relay - good start point or not?

Dies the glow plug relay control the period the plugs are energised?

[MGP]

I would unplug the temp sensor for the glow plug relay first, it should make the relay do the full cycle around 20 seconds or so if it does then it's the sensor if not its the relay

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[syncroandy]

Could be air getting into the fuel (check for bubbles) or timing slipped a bit retarded, are you getting white smoke ?

Also, I currently have no GP relay on my pickup and its not affected starting at all, its just a bit fuelly smelling when cold. I doubt a GP failure would cause sudden starting problems at summer temps.

[Winchweight]

No white smoke at all. Just turns over as though there was no preheat.

Where's the temp sensor?

Starts straight away from warm, but reluctant from cold.

[syncroandy]

What do you mean by reluctant, 'more than 1 second', 'more than five seconds' .. ?

[MGP]

Sorry skim read that as td not tdi. I would agree that on a tdi glow plugs should have little effect especially in this weather unless it's suffering low compression.
Do you have clear fuel lines? can you see any bubbles in fuel when your turning it over?

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[nevill3]

I had a similar problem on my NA 1.6 diesel last year which I managed to cure. It would be slow to start, it just seemed to take too long whilst turning the starter. Later it started cutting out when going down hill and stopped in traffic.

The problem was as others have suggested, air was getting into the fuel lines. My specific problem was a dodgy seal on the diesel pump shaft. The fuel was draining either back to the fuel filter or just leaking out past the seal. I had noticed a small dribble of what I thought was engine oil, but it turns out that it was diesel fuel, that resulted in a very small drip from the bottom of the sump at the back of the engine (nearest the bumper).

I replaced the seal and this cured my extended cranking of the starter, occasional rough idling and intermittent cutting out.

Good luck

[Winchweight]

What do you mean by reluctant, 'more than 1 second', 'more than five seconds' .. ?

Normal start: glow plug light 20 secs engine start after one rotation

Reluctant start: glow plug light 1 sec, engine start after 10 - 15 secs on the starter and a blip of throttle.

I need to check for air next weekend.... Idles fine, starts fine after its warm - glow plug light 1 sec unchanged.