Hey Guys,

This is a really confusing one. I have been driving around fine, no problems at all. Then I topped off this morning and maybe put another 10 miles on since then. Now out of nowhere, she starts up just fine and idles ok but then under load it just has no power. Can barely even move without bogging down.

I pulled the filter and drained it, chucked away the diesel and threw it back on. That little lifter thing to prime it does nothing but regardless she started right back up and is still having the same problem. I checked all the fuel and spill lines but nothing looks obviously wrong.

At this point for it to so suddenly start acting up I am assuming it's related to bad diesel. Any other thoughts?
 
Could be any number of things, is your lift pump working correctly? turbo spooling up? Draining a filter isnt the same as replacing it.
 
As @nobber said, it could be any number of things. It sounds fuel related, and similar to an issue I had last year where air was leaking into the diesel system.

I would get a piece of clear tube and put it in your fuel feed line, between the tank and lift pump, or fuel filter and FIP. Start the engine. If you get bubble in the diesel, it’s an air leak. If you don’t, it’s one cause you have ruled out.
 
Lift pumps are carp, also worth looking at the turbo and you will see a small black 6mm diameter pipe that runs around the front of the engine to the injector pump, if this come off/splits its as gutless as fcuk.

Ps if the filter fixes it buy another asap as you may have bad derv and it may need a biocide additive.
 
Is there a way of testing if the lift pump/turbo side of things.

You should be able to pump fuel with the lift pump lever,disconnect pipe that goes into the filter[ at the filter] from the lift pump and work the lever.
200's will run with a duff lift pump but power will be down.
 
That will just tell you that the pump is pumping fuel, which it will even if it is letting past, it won't tell you if it's keeping pressure. You need to test it properly.
 
I would just replace the lift pump just to eliminate it as the problem. When priming it, the manual lever will not work if the lever in the engine is on the peak of the cam. If this is the case just give the engine a quick turn over then try again.
 
Alright fellas - update. I gave it a go this morning just for ****s and lo and behold she is running as if nothing ever happened.

So by my logic this pretty much rules out a turbo issue or air getting into the system since those wouldn't revert back to a good state.

It could kinda still be bad diesel I guess??

I think my primary theory right now is that it's a pickup issue and perhaps there is some crud in the tank that decided to interfere with my pickup and now has decided to shift a bit. Am I right in thinking I can have a peek in there fairly easily under the drivers seat?
 
Alright fellas - update. I gave it a go this morning just for ****s and lo and behold she is running as if nothing ever happened.

So by my logic this pretty much rules out a turbo issue or air getting into the system since those wouldn't revert back to a good state.

It could kinda still be bad diesel I guess??

I think my primary theory right now is that it's a pickup issue and perhaps there is some crud in the tank that decided to interfere with my pickup and now has decided to shift a bit. Am I right in thinking I can have a peek in there fairly easily under the drivers seat?

If you believe it’s not an air leak because it “comes and goes” then good luck finding the issue. Mine “came and went” for several months, even towing trailers and heavy farm machinery, still ran ok.
 
Air in the fuelk lines has got to be pretty bad to stop a tdi as they self bleed, only really shows when it gets hard to start as the fuel runs back to the tank.
 
Just saying i had exactly the same problems -

200 tdi did 300+ mile round trip in it on the monday - 50 miles on the tuesday then a few miles in the village on wednesday - came to it on thursday and got a mile from home and realised i just couldnt get out of first gear - absolutely no power
- cleaned the filer and primed it - improved - then two minutes later - dying again.
replaced the fuel filter ( £6 locally ) was a bit skeptical and thought there was no chance it was going to be that - like everyone else i was thinking - lift pump
anyway fuel filter sorted it. been going fine since - it was literally an issue that developed overnight.
 
For the price of 30minutes work, it's worth checking that the intake and intercooler pipes aren't blocked/internally collapsed. It has been known to happen.
 

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