[300tdi revs dropping to 1500rpm]

1 hour ago, Snagger said:

Have you checked the low pressure/lift fuel pump?  They often fail with perished diaphragms or leaking non-return valves, and that can give the symptoms you describe.

Tappets are an easy and quick job that costs nothing, so do them, whatever the old man reckons - they should be checked routinely anyway.

I did have a flat spot on my 300Tdi after trying a vegoil/diesel mix years ago, and replacing the fuel filters and running on pure high grade diesel after using fuel system cleaners did nothing.  It needed an injection pump rebuild, and ran very well again after that.  The cam plate and followers do wear flat spots in the pumps; these Bosch units are tougher than the Lucas CAV type, but they are not indestructible.  I used DIeselBobTuning and was very pleased with the results.  The price is very reasonable.  It'd be a shame to scrap the car for something that is fixable.

brand new lift pump.

[300tdi revs dropping to 1500rpm]

OK been procrastinating on this for 6 months haven't been able to resolve it yet. 

fully tested MAF sensor. looks to be working. 

ohms from the accelerator pot nice and smooth. appears to be OK too. 

used an electric pump to supply the injector pump from a bottle so can safely say its not the fuel lines. 

father reckons its not the tappets. 

 

any other ideas to try. leaning towards something electrical. 

if I cant fix it soon I'll probably have to sadly scrap it or sell it for parts. 

[300tdi revs dropping to 1500rpm]

alright i pulled the intercooler out today and cleaned it up along with all the pipework. it had alittle oil but wasnt blocked and no major buildups. hoses were in good condition. the inlet manifold had alittle bit of crud inside it too, but not too much.

didnt resolve the issue.

any other ideas? 

[300tdi revs dropping to 1500rpm]

1 hour ago, steve_a said:

Is it an EDC or mechanical version? This just rings a bell as a sign of the EDC injector having a fault - there isn't that many about and, to make it worse, AFAIK the injector is not available, only refurb of yours is the option.
Have a google on the 300TDi EDC to check it out, but I believe all or most UK 300 Autos were EDC (Australia apparently didn't have any).

Your other option if EDC is to get a manual pump and injector. You can fit them to swap to mechanical only. 

All of this is bumkin if it ain't EDC.

If not then it would suggest a fuel issue, though it's strange, the lift pump is best to have, but you can definitely run without it and probably notice no difference (I didn't), and everything else would tend to be it either works or not on these motors.

pretty sure it's not the Bosch injector, had an issue with that in the past because the plug was filthy, always got check engine lights, stalling and lots of banging because the timing was out.

[300tdi revs dropping to 1500rpm]

20 hours ago, jason110 said:

Put some diesel in it. I wouldn't trust the fuel gauge. Have you checked the air filter? Is it smoking? Have you had any work done to it recently? Check the intercooler hoses, they might be collapsing under vacuum. 

it's got fresh fuel, first thing I suspected was water in it so I ran it empty and put new stuff in.

checked the air filter and the sensor next to it, looked good.

do all my own work was previously my father vehicle who also did his own work.

I will check the intercooler hoses.

[300tdi revs dropping to 1500rpm]

On 23/01/2017 at 4:06 PM, hangover said:

When were the tappets last adjusted ?

I think around 5 years ago.

[300tdi revs dropping to 1500rpm]

My '95 land rover discovery auto diesel with the 300tdi engine was sitting for afew months and when i got it going again its got this weird issue with the engine.

when you push down the accelerator the revs will go up like normal but will soon drop down to just below 1500rpm and stay there, no matter how far you push the peddle in it wont go any higher

it is possible to get it working steady but only if the peddle is pumped up over 3000rpm

Heres a video showing it:

https://www.youtube.com/watch?v=zdaEkRXyZWM

I have fresh fuel, cleaned the sedimenter, new fuel filter, new lift pump, checked injectors were working correctly, usual exhaust emissions.   

would love to get out driving again as its my kayak wagon, any help greatly appreciated.

[d1 95' internal light fuses and other electrical issues?]

Hi working on a couple of electrical issues

1. The clock works but the backlight does not turn on, the bulb is fine was wondering which fuse this uses

2. Auto gear shifter lights which are on the sides of the stick also don't light bulbs replaced

3. Central locking dead and both front door locks reluctant to fully rise leading to bad situation of keys locked in car after popping back into house to grab stuff

4. Rear electric windows don't work but had one working for a short period of time perhaps a bad ground??

Any help on these issues would be great

[300tdi missing until warm]

edc injector cable plug may have been not fully connected.

wiggled the cable in the dark the other night and everything running good except for check engine light, drove down the road 500 meters then the check engine light started flickering and the knocking started really badly, limped home after that.

today gave it a go with some contact cleaner and a firm pressing. no more check engine light and working good, seems like more power but might be the new fuel filter and the sedimenter which hadnt been cleaned out in 20 years.

[300tdi missing until warm]

Hi, recently my 95' discovery has been missfiring after starting at first it will do it at idle but as the engine warms up the number of rpm required to get a miss will rise until they go away and the temperature gauge is midway.

It takes about 5 hours in 15c weather for it to cool down and recreate the problem.

Any help would be greatly appreciated.