300tdi power checklist?

Rorie · Apr 30, 2019

100 posts about lack of power. Read loads today. But wondering if there is a "check list" to identify the issue? I've put my summary of today's reading below, but maybe it's all wrong...

I swapped out my 300tdi (warped cylinder head) for a 300tdi out a disco with 160miles on the clock. I'm noticing a lack of punch and ability at high speeds or on hills.

I have:
New hoses all round
New intercooler (standard)
New fuel filter
Reset tappet gaps

So what's next?
Oil pressure check?
Cylinder compression check?
Clean injectors with fuel additive?
Replace injectors?
Turbo gauge to check its working properly?
What about timing, should that be checked and aligned?
Anything else?

I want a good base engine before I look to tweak anything with boost pins etc

jamesmartin · Apr 30, 2019

id check timing and fuel supply ie lift pump or air been drawn in

Rorie · May 1, 2019

Thanks for the reply.
I'll have a look at timing. I did check the pump before i put in the engine (replaced gasket too). But maybe worth another check.
Where would be suspect area for air being drawn in? Is there an easy way to check?

mick 1986 · May 1, 2019

Rorie said:
Thanks for the reply.
I'll have a look at timing. I did check the pump before i put in the engine (replaced gasket too). But maybe worth another check.
Where would be suspect area for air being drawn in? Is there an easy way to check?

Use some clear hose/pipe between the fuel filter and injection pump. @nobber has said to use clear pipe on the return lines from the leakback pipes, but this isn’t something I have ever done.

nobber · May 1, 2019

Air would make it miss, fuel supply pressure could be the problem, I doubt its injectors as it would run rough and miss. Turbo might not be working correctly.

nobber · May 1, 2019

Generally a fuel supply pressure issue will allow the engine to idle properly but the more you give it the less it gives back, which would explain your symptoms. Check the fuel pressure.

Rorie · May 15, 2019

Ok, so an update with no resolution!
Timing was out, so i sorted that
Fuel lift pump has a mesh filter, it was full of rubbish, so cleared that
I checked all the pipes from teh tank to lift pump, filter to diesel injector and return, all look ok and the correct way round

On the lift pump, i can use the manual primer and i can feel resistance and hear the diaphragm working. Does that mean the lift pump is ok, or could it still have issues? Or do i need to check fuel pressure to identify if the lift pump is goosed?

What is next to check?

Each issue i found (timing, dirt in filter) i thought i'd found the issue, but no!

To explain further, if in 5th cruising along, as soon as i come to a hill power drops right off with foot to the floor.
*Sometimes* in 4th and 5th it feels like i just cant get the revs to increase enough, it seems to bottom out with foot to the floor even on flat ground. Point it down a hill and the revs and speed pick up. So this all looks like a fuel issue, right?

Flossie · May 16, 2019

Check boost pressure next.
15psi for the 300 iirc.

Rorie · May 16, 2019

Flossie said:
Check boost pressure next.
15psi for the 300 iirc.

Ordered a boost gauge.

Checked fuel lines tonight and none of them are blocked (like I kinda hoped!)

Flossie · May 16, 2019

Also, and I'm not sure about this, some Bosch injector pumps have a fine filter located in the inlet port?
My 200 doesn't have one but the 300 might?

300tdi power checklist?

Rorie

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jamesmartin

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Rorie

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mick 1986

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nobber

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nobber

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Rorie

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Flossie

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Rorie

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Flossie

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