300tdi wont run below 600rpm

Bloody hell, hope you can get this sorted. Have you checked compression?

landowner said:

Right....

Fuel coming to injectors when cranked over

Drained tank today and put 15 ltrs of fresh diesel in

New lift pump was knackered so fitted another new one

Gave it just short of a quarter of a turn on the pump to give it more fuel.

Still a little down on power

Lift pump working ok and bled filter.

Ticks over at 750 rpm

Small bubbles in leak off pipes but not much

Still wont start even when just switched off, wont even kick

Baffled

Could be injector pump perhaps

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it easy could be ive had a few similar ,pump doesnt create enough pressure at low turn over revs ,i had to explain several times as they tested it 3 times reckoning it was ok but test speed they usewd was high and fault (worn head )only showed at low

jamesmartin said:

it easy could be ive had a few similar ,pump doesnt create enough pressure at low turn over revs ,i had to explain several times as they tested it 3 times reckoning it was ok but test speed they usewd was high and fault (worn head )only showed at low

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Thinking along similar lines last night but hoping its not the injector pump.

This problem came on suddenly, the motor has started fine since I bought it last April, not as instant as the 200 I had but more or less straight away.

One morning it took ages and was just kicking so I thought leak off pipes and renewed them, It was ok after that for a week then nothing, one morning it refused to start and wouldn't start hot either so I blamed the fuel.

Its not the fuel or fuel related such as filters and lift pump so I guess it must be the injector pump.

Which means that it's scrap as far as I'm concerned because I cant change the pump in the cold and damp and cany really afford for anyone to do it for me as it would mean cambelt, waterpump, P gasket and all the hastle of snapped studs etc so thats out.

Maybe stick it on ebay and have it running when buyer arrives

sounds to me like ya got an air leak somewhere in the fuel system or maybe a dicky connection on the stop selonoid thats waht mine woz

Tøxïc§øX™;2338268 said:

sounds to me like ya got an air leak somewhere in the fuel system or maybe a dicky connection on the stop selonoid thats waht mine woz

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Something to check but where is the stop solenoid? mines got a plastic block with three wires coming from it, I presume its behind that lot

Not checked stop solenoid yet but.............

Still wont start without ether (easy start) but once started it runs great and since I put some bio back in goes a lot better than it did, it'll pull strong on half throttle so easier to drive and no smoke at all.

Must be the 1/8th of a turn on the fuel screw that has given it more life than it had and got power back at low revs so the only problem now is that it wont start

Think I'll just put up with it and get on with sorting the 90 out, rather spend time on that than this stupid Disco

jamesmartin said:

it easy could be ive had a few similar ,pump doesnt create enough pressure at low turn over revs ,i had to explain several times as they tested it 3 times reckoning it was ok but test speed they usewd was high and fault (worn head )only showed at low

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Would value your opinion on how quickly the wear would come to the point that there was insufficient pressure for starting.

It has never started as good as the 200 I had, I would say two engine turns instead of one before it fired, could it have been on the cusp of failure the past few months but surely it would at least kick now and then when trying to start a hot engine.

I'm not convinced it is pump wear but there is not as much spurt when cracking injector pipe off as I would have hoped for so maybe pump is kaput
Having said that the pump did drag fuel from the tank and run the engine ok when the lift pump went

landowner said:

Would value your opinion on how quickly the wear would come to the point that there was insufficient pressure for starting.

It has never started as good as the 200 I had, I would say two engine turns instead of one before it fired, could it have been on the cusp of failure the past few months but surely it would at least kick now and then when trying to start a hot engine.

I'm not convinced it is pump wear but there is not as much spurt when cracking injector pipe off as I would have hoped for so maybe pump is kaput
Having said that the pump did drag fuel from the tank and run the engine ok when the lift pump went

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have you tried unscrewing the delivery valves and seeing if anything comes out

jamesmartin said:

have yoou tried unscrewing the delivery valves and seeing if anything comes out

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I've cracked all the injector pipes off and fuel comes out when cranking, did em back up one at a time still cranking like the old days of bleeding but nothing, she wouldn't start.

Whiff of ether and she crack up and ticks over steady as a rock, revs freely and just a bit of black when given a boot full but no smoke when firing up which is strange as I should get a puff of grey/black when starting

Faced with a puzzle like that, I'd be tempted to run it into a garage and let them spend a hour or two getting to the bottom of it.

Steviecops said:

Faced with a puzzle like that, I'd be tempted to run it into a garage and let them spend a hour or two getting to the bottom of it.

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Spose they could test pump pressure and check filters etc but the only thing I havn't done is check pump pressure

Dont trust garages as most seem to know less about mechanical things than I do, they just plug in to a computer

If it runs OK once it's started, the only difference between then and when you crank it over is rpm. Someone said a few posts ago that they have known pumps to lack pressure at low rpm, but you're getting fuel to the injectors at cranking speed. Even if it wasn't enough fuel, if some is getting into the cylinders, you'd expect it to at least try to start, wouldn't you? Especially when the engine is up to temp?

Steviecops said:

If it runs OK once it's started, the only difference between then and when you crank it over is rpm. Someone said a few posts ago that they have known pumps to lack pressure at low rpm, but you're getting fuel to the injectors at cranking speed. Even if it wasn't enough fuel, if some is getting into the cylinders, you'd expect it to at least try to start, wouldn't you? Especially when the engine is up to temp?

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Yes you would expect it to kick a little but nothing, I think I'm going to have to take the plastic box off the back of the pump and try and find the stop solenoid just in case its sticking half shut or somethin

Baffled even more now !!!

Put bio back in after running on pure diesel (still wouldn't start on Diesel) I'm now on about 80% Bio


Still wont start but runs lovely, loads of power all the way through except maybe between 1000 and 1500 rpm.


Did a few blasts away from the lights in the dark with vehicles following to check smoke, took her round to 4000 in first, second and third, went like stink but no smoke, not a whisper, nothing showing in the lights of the closely following vehicles, not normal surely???


Difficult to stall the engine, engine still trying to pull away on tickover in first gear with the brakes on, goes down to 500 rpm before she dies??

Doesn't sound like a worn pump to me but why wont she start? why no smoke when she starts up on ether, is my excess fuel thingy faulty do you think ??


How do I get to the stop solenoid please (98 300tdi no ecu) Ta

If it was mine, is had given it to someone else to sort out by now, lol

Steviecops said:

If it was mine, is had given it to someone else to sort out by now, lol

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Well no one on here knows whats wrong with it so what chance has a garage?

A garage will test fuel delivery and injectors and maybe injector pump but to my mind there is nothing wrong except maybe the stop solenoid may be sticking and when the engine fires up on easy start the pump draws fuel and the stop solenoid flips open (just guessing)

That or the excess fuel device is faulty??

so how do I access the stop solenoid please anyone?

Depends if you've got an anti tamper one or not. If its a black box on rear of pump,you'll need to drill it off to get to solenoid. It'll have 3 wires going to it aswell. If its like mine it'll be 1 wire and nothing in the way. I found it fiddly trying to get a spanner round it and it was a right sod putting the wire back on top,but I left everything on the pump,if I do another one I'll strip it down.

MPfive said:

Depends if you've got an anti tamper one or not. If its a black box on rear of pump,you'll need to drill it off to get to solenoid. It'll have 3 wires going to it aswell. If its like mine it'll be 1 wire and nothing in the way. I found it fiddly trying to get a spanner round it and it was a right sod putting the wire back on top,but I left everything on the pump,if I do another one I'll strip it down.

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Right ta
Mines a black box with three wires

I'll have a go at it next week, too busy this weekend , the damn Disco never stops, its like a taxi at weekends going here and there etc etc.

Might take injector pipes off before I start then

Waaaahooooo !!!! progress at last and my pump isn't on the way out

Started on easy start as usual this morning and drove a mile and a half to the builders yard. Heater not hot yet, just coming warm.

Spent about 20 mins getting some wood cut to length cause it wouldn't fit in Disco (4 Mtrs)

Put wood in Disco and tried it, she fired almost first turn, so quick I got a fright

Went to my brothers place and parked up for about two hours.

Got in and she fired first time

Went 4 miles to get dinners from pie shop, came out and she wouldn't start, nowt , not even kicking. (Easy start again)

Carried on to Tesco and got buiscuits, came out and she fired first turn

Went back and parked for 4 hours and she started first time again even though stone cold

So now intermittent starting problem whether hot or cold dont matter so I suspect that little box on the pump may be at fault

At last, progress. Of a sort!