HELP on a 300 tdi discovery needed

[Nick154]

Has anyone got the computer system to find the fault codes, check the maf sensor and the fueling as my brother is banging his head against a brick wall at the mo.

It's a P plate 300tdi and it has no power and gets alot less the higher the revs go, it also hesitates on acceleration and under load (ie going up hills).

So far we have changed the following:

Fuel up lift pump
de cated the exhaust
changed the gear box oil and filter
fuel filter
air filter
engine oil
cleaned out the inter cooled and cleaned out the pipes
egr blanking plate on

All to no avail

We are in stevenage in Hertfordshire.

if someone has got a maf sensor we could try we would be very grateful as it would add another thing to the tryed list.

Thanks in advance

Nick

[Nick154]

oh yeah forgot to mention, he's also getting very low mileage to a tank of fuel (about 240 miles to £90) which is about the same as my V8 he's not very happy!!!!!

[Porny]

P reg...

Is it an Auto??

If not, sure it's got a MAF sensor, as only the late 300Tdis Auto's were ECU controlled... and thus have the MAF sensor.

Any other 300Tdi is mechanically controlled and thus have no sensors, ECU or any form of diagnostics....  post 1996 will have a OBD11 port, but this is only for the 10AS alarm unit and the ABS (except on late Auto's - OBD will also be for the ECU)

There a few things that could be wrong for it to be down on power  


Ian

[landandy]

sounds like injector pump to me. had mine rebuilt about £250. First thought it was fuel filters but it had to be the big one lol

[Budgie]

If it's a manual then look for splits and delamination on the intercooler hoses, this involves removing the hoses and looking inside as well as an external inspection. This may also produce black smoke from the exhaust as there will be less air to mix with the fuel.

Also the injector pump diaphram may have split which won't be taking the engine to full fuel, no black smoke from the exhaust.

[mickelson]

Is it turfing out any unusual colour smoke? Black? Lacking power could easily relate to the turbo, but normally this would show up with excess smoke as well. when did you last put some injector cleaner through it, what condition are the injectors in? if they werent working well and were clogged up, they wouldnt shut properly and therefore would produce black smoke as they are burning extra fuel when they shouldnt be.

[mickelson]

One thing i will say, is always look for the simple things first. majority of time it is and if you can use a simple process of elimination then it may save you a few quid. Ensure you are getting plenty of fuel to the injector pump by pumping the lift pump and undoin the bleed screw on the FIP. Make sure the whole air induction system is free from holes and completely sealed. Have a feel of the turbo blades, is there excessive play in them, there should only be a very minor amount of up and down movement.

[Nick154]

Thanks everyone i'll pass on the info.  By the way it's an auto and had some injecter cleaner in it a couple of weeks ago.

[freelanderpx54]

When I put some injector cleaner through my TD5 it took a week or two to settle down

[lee celtic]

dump valve jammed open in the turbo?

if it's the same as a 200 tdi is the diaphram in the injector pump in the wrong way round this makes them guttless

tappets (gaps) holding valves open letting explosion past valves into exhaust (burnt valves)

Timing

blown intercooler or hoses?

my best mate Mz666 had somthing similar turned out to be a peice of swarf in the injector pump.?

fuel starvation at high revs due to blockage in certra thing that spins out grime and water behind the drivers side rear wheel arch.

Thats all I can think of at  the moment but I will ask the anorak at work tomorow

most of them are free worth a go :D