Cold engine start - strange accelleration - low power

I noticed that my 300 TDI defender always struggles to get up the driveway when starting it cold in the mornings. Even in warm weather. The driveway is not excessively steep and I never saw any other car struggle. Even with the foot to the floor, I usually struggle to get up even when in low range. I somehow just accepted this as "well that's how it is...". Otherwise I never notice a distinct lack of power when driving it on a flat road. When the engine is warm after driving for a while, the defender is still struggling a little, but manages better.

Now that it's getting a bit colder and closer to freezing, I also started to notice two other problems:

1. On start-up, it sometimes takes a few seconds until it gets going under a lot more initial black smoke than usual. The engine turns, but doesn't seem to fire properly.

2. When I accelerate after starting the engine, it doesn't rev up initially at the very first try in the morning. There is a solid ~3 second delay until the engines gets revving. When it eventually works, the engine start "coughing" a lot of black smoke when the accelerator is let go. I uploaded a video to show the second part: It was worse when I tried it just before without recording it.

The injector pump is brand new. Fuel filter is also new. I also checked the earth to the bulkhead- seems fine. I also checked the voltage on each glow plug and couldn't find a fault with it. Could all my problems be related, and if so, what could be the culprit?

Air cleaner and its pipes in good order ?
Pipes from turbo to cooler to engine good. ?
Waste gate actuator not stuck open, give the engine a good rev up and you should see it move some.

tottot said:

Air cleaner and its pipes in good order ?
Pipes from turbo to cooler to engine good. ?
Waste gate actuator not stuck open, give the engine a good rev up and you should see it move some.

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Air filter and pipes are in good condition. Same goes for the Turbo. I get a max. boost pressure reading of just over 1 bar. Where do I find the waste gate actuator?

When starting on a hill in first gear, I don't see the boost pressure move at all though.

That is ticking over way to low
Did you fit the inj pump?
How old is the lift pump?

The 200tdi is a bit different to the 300 but I suspect the same applies.
Ignore the glow plugs, they will start fine without.
It sounds like you have air getting in or
Timing is out or
You have the flow and return banjo bolts the wrong way round. They look identical fitted but the flow bolt has a much larger port than the return, you'll have to remove them to check.

The glow plugs can have 12v to them but that’s not proof they work, there should be a low resistance between lead and block which is a better test. But need all the power leads disconnected first

Is all injectors working ok

Waste gate actuator is on the side of the turbo.

steve2286w said:

The glow plugs can have 12v to them but that’s not proof they work, there should be a low resistance between lead and block which is a better test. But need all the power leads disconnected first

Is all injectors working ok

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tested the restiance as well - and seemed fine! I'm not sure how to check the injectors. Ran about 1000km with diesel cleaner though to blow out any dirt.
I'll check the waste gate actuator next.

What's the best way to check for air leakage (in the fuel system I assume)?

ZeHerman said:

I noticed that my 300 TDI defender always struggles to get up the driveway when starting it cold in the mornings. Even in warm weather. The driveway is not excessively steep and I never saw any other car struggle. Even with the foot to the floor, I usually struggle to get up even when in low range. I somehow just accepted this as "well that's how it is...". Otherwise I never notice a distinct lack of power when driving it on a flat road. When the engine is warm after driving for a while, the defender is still struggling a little, but manages better.

Now that it's getting a bit colder and closer to freezing, I also started to notice two other problems:

1. On start-up, it sometimes takes a few seconds until it gets going under a lot more initial black smoke than usual. The engine turns, but doesn't seem to fire properly.

2. When I accelerate after starting the engine, it doesn't rev up initially at the very first try in the morning. There is a solid ~3 second delay until the engines gets revving. When it eventually works, the engine start "coughing" a lot of black smoke when the accelerator is let go. I uploaded a video to show the second part: It was worse when I tried it just before without recording it.

The injector pump is brand new. Fuel filter is also new. I also checked the earth to the bulkhead- seems fine. I also checked the voltage on each glow plug and couldn't find a fault with it. Could all my problems be related, and if so, what could be the culprit?

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That doesn't sound right at all from what you have written and your video.

The 300tdi is a good engine, mine will pull 80mph up a steep motorway I sometimes drive on, it is almost an annual test to see how things are, if it romps up this hill in 5th then I know shes in good form.

There are just so many things this could be, fuel starvation is one of the simplest things I am thinking here.

If it was mine I would check fuel flow first. With the engine running I would undo the bleed nipple on the filter housing and expect a constant flow of diesel shooting a good 8-9inches across the engine bay, I would then expect the same from the bleeder on the pump. If I did not see this at either I would start looking into the fuel system probably first with a new filter just to be sure then go from there.

I have had many a fuel issues over the years of Landy ownership and my own top 3 issues with my vehicles were:

Shot lift pump.
Piece of silicone in the pickup pipe in the tank.
Massive air leak on the suction side drawing loads of air but of course not leaking diesel which made it a pest to find.

It could then become more complex, like injection pump issues etc. etc. but start simple. Prove good fuel flow.

ZeHerman said:

What's the best way to check for air leakage (in the fuel system I assume)?

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Obvious and simple - thank you. I'll report back soon to hopefully help the next person reading this.

I appreciate all the knowledge and input from everyone!

steve2286w said:

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Clear fuel line is a good idea at all times but all the stuff I ever see is not long term fuel compatible.

Of you replaced the FIP is it timed right? That can have quite a noticeable effect if it’s out

discomania said:

Clear fuel line is a good idea at all times but all the stuff I ever see is not long term fuel compatible.

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Yes agree that was a temporary diagnosis of my rough running. On that occasion wasn’t air

steve2286w said:

View attachment 251202

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Steve what is the T in the vac pipe for?

Not sure if it improves things but I kept the vacuum reservoir for nostalgia’s sake

flat said:

Of you replaced the FIP is it timed right? That can have quite a noticeable effect if it’s out

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It was replaced by a very reputable mechanic specialized on Defenders, so I'm trusting it for now.

steve2286w said:

Not sure if it improves things but I kept the vacuum reservoir for nostalgia’s sake
View attachment 251336

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I like the breather pipe into the di manifold, and the dipstick bracket, neat little touches that make things stand out from the norm.

ha I thought that’s where the breather would normally go, the dipstick wouldn’t bend easily to fit original place so chopped a bit old ally front floor up for the bracket, I never chuck things out, used a couple more pieces off floor to repair both rear wing bottoms.
Just starting to come round to the idea of clear outs now I’m retired and got more time