300tdi jumping from 2000rpm to 2500rpm

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Larry365

Active Member
Posts
558
Location
Lincolnshire, UK
Evening all

This might have been covered but I cannae find the right terminology.

The engine is jumping from 2000rpm to 2500rpm without any increased throttle.

I was messing about last night, waiting for the missus to get out of work and basically took the engine through the revs in 250 increments and holding. When reaching 2000rpm and holding, it took its self up to 2500 and held. Does it every time without fail, and to be honest, I have noticed an increase in power here when driving but always just assumed it was the turbo kicking in. No sign of this happening anywhere else in the range (up to about 3500).

I've been running this one of veg for about 3000 miles now, 50/50, and the revs have been a bit iffy when cold, not to mention start-up taking several turns.

Anyone got any suggestions?

Cheers.

Note, I am swapping out fuel lift pump tomorrow, just to get it done. Maybe this will sort the issue out though I ordered OEM, but its britpart :mad: Is OEM britpart alright? I always avoid them, but this is the first time I have had any OEM britpart stuff..

EDIT, I have recently changed fuel filter and cleaned sedimenter too (about 1000 miles ago).
 
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edc or throttle cable? you could try it with boost pipe to pump removed

Did you see my message? :D cheers for taking a look!

Could be the throttle cable. I'll try my best to give it the once over. I suppose one way to do this would be to have someone watch the rev counter while increasing the revs at the pump.

Do you know anyone in Lincs who will take a look at the pump and give it a tune? Stratton seem reluctant and so do Lovell.
 
Did you see my message? :D cheers for taking a look!

Could be the throttle cable. I'll try my best to give it the once over. I suppose one way to do this would be to have someone watch the rev counter while increasing the revs at the pump.

Do you know anyone in Lincs who will take a look at the pump and give it a tune? Stratton seem reluctant and so do Lovell.

yes:) i used to work with barry stratton at hobsons, he did service i did the engineering, my brother in laws a pump specialist ,if it comes to that eventually
 
yes:) i used to work with barry stratton at hobsons, he did service i did the engineering, my brother in laws a pump specialist ,if it comes to that eventually

Ahh hobsons, near the satellites?

I'll see how I get on. I have got a feeling that the veg oil has triggered all this. From day one of using it, i've been faced with bad start ups, jumpy acceleration when cold and lots of smoke. Unfortunately, my tank is full to the brim so gonna have to wait to see if no veg solves all.

Never had any issues with my previous 300tdi on 50/50 but it was much lower mileage, around 50k as opposed to 120k on my current.
 
yes at donington near stenigot radar/communication site what was , could have been the biggest and best independant landy business but buggered by politics and bull****, whats you mix of veg and derv ?
 
yes at donington near stenigot radar/communication site what was , could have been the biggest and best independant landy business but buggered by politics and bull****, whats you mix of veg and derv ?

Shame.

Exactly 50:50 using Pride rapeseed, actual rapeseed oil but it does have the e900 antifoaming in it (mixed opinions on this), and diesel is from anywhere that isnt a supermarket.
 
Swapped out the fuel lift pump. Old one seemed ok to be honest but it's got a new one now.

Had some bleeding issues. Didn't want to self bleed so I loosened off the 10mm bolt on top of the filter. Lovely hiss but of course the ####ing thread stripped on the cast bracket. Now the air in the system is worse.

Will the system draw air from this bleed bolt? If so, then problem should be solved when the bracket is replaced, if it can't draw air from here then it must be getting in somewhere else. Olives done up properly so I can only imagine the bleed bolt is the issue.
 
Yeh just put my finger over the hole. It's sucking. I guess that's that until Monday then. Can't think of any way of sealing this until i replace it
 
After changing the lift pump, i was gettting constant lack of fuel. I tried to assist the bleeding process by slackening the 10mm bolt on top of the fuel filter. The thread stripped on the housing so I removed the filter, helicoiled a new thread, replaced copper washer and fitter bolt. Sealed.

New olives and nuts on the fuel pipes. Nice and tight, no leaks as far as I can tell.

I then cleaned out and replaced the copper washers on the banjo bolt. Sealed

I took out the old filter and replaced it with a new one which I filled up before fitting. Done.

I removed the sedimenter, cleaned out and put back. Done.

I am still have fuel issues. Rough ticking over, cant get the revs above 1500. Tried idleing at 1200. Ran for about 4 mins then lost fuel again. Rinse and repeat.

Fuel is getting in from the tank as I had a sniff of the exhaust and could smell veg. Running 50,50. Viscosity seemed fine when draining sedimenter and filter. Though I do wish the tank was 100% diesel as the engine ran best when using the neat diesel I had used to pre-fill the filter.

Does anyone have any ideas what might be causing this to happen?

I have primed it every time etc, there IS resistance on the lift pump. I am trying to keep the revs low and smooth.

It could be the fuel pump but obviously this has only happened since replacing the lift pump. Maybe the fuel pump took a hit when running semi-dry?

Any help would be much appreciated.
Cheers
 
get a length of pipe and stick it on the in side of the lift pump, run it into a can of diesel and see if things improve at idle and when you rev it.
 
Ahh hobsons, near the satellites?

I'll see how I get on. I have got a feeling that the veg oil has triggered all this. From day one of using it, i've been faced with bad start ups, jumpy acceleration when cold and lots of smoke. Unfortunately, my tank is full to the brim so gonna have to wait to see if no veg solves all.

Never had any issues with my previous 300tdi on 50/50 but it was much lower mileage, around 50k as opposed to 120k on my current.

My 300Tdi was exactly the same on 50/50 veg oil mix, I have tried on and off and finally packed in veg oil all together, ran the tank almost empty, filled up with diesel, added two tins of Liqui Moly fuel system cleaner and the difference with in 100 miles was staggering.
 
get a length of pipe and stick it on the in side of the lift pump, run it into a can of diesel and see if things improve at idle and when you rev it.

Good idea, I'll give that a try tomorrow.

My 300Tdi was exactly the same on 50/50 veg oil mix, I have tried on and off and finally packed in veg oil all together, ran the tank almost empty, filled up with diesel, added two tins of Liqui Moly fuel system cleaner and the difference with in 100 miles was staggering.

Yeh I am definitely going back to diesel. Just dont know what to do with the 80litres of mix thats currently in the tank.

Anyone want to come siphon 80 litres of 50/50 veg diesel for 40 quid?
 
just keep brimming it with diesel to weaken it :)

could always drop 25 lts out into a jerry can, top with diesel and readd the mix later with more diesel
 
Ok, so I've done the math, and taking into account what was in there previously, whats been taken out and whats been added; the current mix is about 70% diesel, 30% veg. 69.134% to be exact :D.

The engine is starting up perfectly after 1 turn, and ticking over fine. Any increase in revs however is stuttery and rough. The engine will rev up to 2500 relatively smooth but will not go beyond 2500, if you try and push it, the revs will drop below 1000 and it will stall. It stops dead at 2500, which may be related to the initial problem of it jumping from 2500 to 3000.

I was thinking of running some Liqui Moly diesel purge through the system, followed by an additive in the tank; running the tank empty and filling with neat along with another can of additive. Does anyone know if putting the inlet pipe from the lift pump straight into the can of Diesel purge is sufficient? Or should i put the inlet and return pipe in the can?

All this followed by a pump tune, carried out by someone who knows what they are doing :) (any takers?)

Many thanks
 
engine running, undo the bleed screw and see if it squirts fuel out to check new lift pump isn't knackered.

take the air filter pipe off the tubo when idle and see if if that helps with revs

add more diesel in, remove as much veg as poss, see if that works

if the above doesn't help, when did you last change the fuel filter? do that
 
Does Landyzone give out rewards for idiot of the year?

Fixed the issue.. If I tell you the bleed valve was sucking and not blowing, can you work out what I had done wrong? 5 points for the correct answer. I'm surprised it was still even ticking over.. So apologies for wasting a bit you peoples good time there. Won't make that mistake again. At least its sorted, and thanks for the replies. Made my week.

Still have the 2000 -2500 auto-jump problem though. I've uploaded a video if anyone could care to take a look. In the video, I am gradually increasing the revs. I hold the throttle @ 2000rpm and thats when it goes up to 2500 on its own. Though not shown in the vid, after 2500rpm, everything is normal, its just at that stage.

Filter has been changed, sedimenter has been cleaned. Not yet on neat diesel (~30% veg) but I get the feeling thats not the issue here.

YouTube - Discovery 2000rpm - 2500rpm
 
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