Disco 1 300tdi starting problem

Today I replaced my glow plugs after finding the Disco required two glow plug heat cycles to start.

Sadly the new plugs have made it worse. Very very sluggish to start. I used ETC8847 plugs, which I believe to be correct.

Any ideas? Thanks.

The right injectors.
Sounds like a wiring issue and you've disturbed it changing them only to make it worse.
Check all connections are right and tight.
Is it the correct cable. Trace it back and check everything.
Also check the plugs are tight and not leaking.
Did you change all 4?

Okay, checked everything was tight, plug #4 is a bugger but it’s as tight as I can get it. The continuity of all four new plugs is the same 2.42 ohms.

The wiring is straightforward and fairly tight around the engine bay, pretty sure I didn’t dislodge anything.

On the off chance it was just build up from repeatedly starting the engine, it took it for a 20 blast. I’ll try again tomorrow morning.....

Update:

I’m only getting 10volts to the glow plugs when first turning on the ignition, should be 12v. I’m going to test what voltage I get to the first lead (connected to glow plug #4, with it disconnected from the glow plugs in series).

It has been suggested that the problem might be with the battery.... the battery was only just just able to heat 3 glow plugs (one faulty). Now I’ve fitted four good ones the failing battery can’t cope. More to follow.

When my battery was knackered it usually heatd the glow plugs OK but it really struggled to turn the engine over. Try doing a jumpstart or changing the batt for a known good one to see how you get on. funny how you got less Volts to the plugs though. At least it's a 300tdi, much easier to sort than the same prob on a TD5, or oops, is at an EDC auto?

Could also check the earth(s) from the engine to the body/batt. Then again could do the same with the starter. but that 10volts does look like the main if not the only problem.

With checking the relay?
I'm pretty sure there is one on the pole heat curcuit.

Well, some story. The voltage at the first lead (leading to GP #4) reads 12.6 volts when starting the ignition, when disconnected from the GPs. Note: battery reads 12.7 volts. All good.

Each GP measures 2.5 ohms when disconnected. All good.

Removed the interconnecting wires and the resistance across all four terminals of the wire and between each is 0 ohms. All good.

It’s the battery....I’ll borrow a jump start pack tomorrow and confirm. It seems fixing one problem has highlighted another.

A decent 300tdi should rarely need glow plugs and certainly not at this time of year. Mine certainly doesn't and I'm running about 60:40 cooking oil

s0785488 said:

Today I replaced my glow plugs after finding the Disco required two glow plug heat cycles to start.

Sadly the new plugs have made it worse. Very very sluggish to start. I used ETC8847 plugs, which I believe to be correct.

Any ideas? Thanks.

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Sluggish in what way? Is it slow to crank, or is it cranking fast?

The static CR is quite high on a diesel. You need a good battery to spin it over well. Spinning it slowly will take longer to start as a rule.

As for the glow plugs. I'm pretty sure the 300Tdi is like the 200Tdi in this regard. Very stout and hardly needs them. I haven't run glow plugs on two 200Tdi's for years. And they still started in -5 temps with only a handful of cranks (basically 3-4 secs). In the current weather conditions you shouldn't need the glow plugs at all. So I'd surmise the issues you are having are completely unrelated to the glow plugs and glow circuit.

If it is cranking well but not starting then I'd be considering a new lift pump and a new fuel filter, as well as looking for air leaks.

+1 to both comments, and I found if the glowplugs were a bit iffy just a little bit of gas pedal helped start in cold, Very cold, weather.

It’s an auto not sure whether EDC.

When it does finally start there are plumes of white smoke, only for a second, I’m assuming this is diesel and that fueling is not the problem. It cranks reasonably well.

I got hold of a massive jump starter but no improvement. Less likely the battery now.

Earth straps look good.

Where is the starter relay? Drivers footwell (RHD vehicle), black plastics or silver metal on the right side?

I would have thought you'd get black smoke not white, I certainly do.

And I certainly wouldn't describe the smoke as plumes either.

Ok, Black smoke is due to....? (Carbon maybe? thick but burnt fuel?)
White "smoke" is due to....? (Unburnt but vaporized fuel maybe? Or maybe water vapour and not fuel related at all?)
I really am open to suggestions.

s0785488 said:

Earth straps look good.

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Take them off and clean them up with a bit of emery cloth and refit with a smear of grease or vaseline, you would be surprised how many electrical connections look good but aren't.

If the smoke is kind of grey and lingers in the air its unburnt diesel so probably injector(s). Does it run well otherwise? Slim chance your bottom pulley has a worn key or keyseat which is affecting the timing causing difficult starting. When was timing belt last done?

Kev12 said:

If the smoke is kind of grey and lingers in the air its unburnt diesel so probably injector(s). Does it run well otherwise? Slim chance your bottom pulley has a worn key or keyseat which is affecting the timing causing difficult starting. When was timing belt last done?

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If it's cranking for a while then there will be a good bit of unburnt fuel in the cylinders.

Could be injectors but sounds electrical from it suddenly getting worse with new glow plugs.

dieseldog69 said:

If it's cranking for a while then there will be a good bit of unburnt fuel in the cylinders.

Could be injectors but sounds electrical from it suddenly getting worse with new glow plugs.

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Yeah does sound like it with the new plugs being worse. I mention timing as it shouldn't be cranking for long, glow plugs or not

Kev12 said:

Yeah does sound like it with the new plugs being worse. I mention timing as it shouldn't be cranking for long, glow plugs or not

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For peace of mind I would be looking to get the cam belt replaced and set the timing correctly and then work back from there, timing belt kits are cheap enough and gives chance to inspect keyway etc,.

Injectors can be serviced and new nozzles to rule them out and the glow plug system could be Gerry rigged to ensure they work then the system reviewed as necessary.