300Tdi Down on Power

[mpb]

My 1996 300Tdi Defender 90 seems down on power. The fuel consumption seems low as well. 21MPG.

The engine has done 60K miles & im the second owner buying it in 1999.

The Defender has got a Safari Snorkel, K&N Air Filter, 235 85R16 Colway Muds, GKN Overdrive, Zues timing Gears, Kenlowe fan fitted.

I have just been out & compression tested the engine, the results are

Cylinder 1 - 460 PSI

Cylinder 2 - 500 PSI

Cylinder 3 - 480 PSI

Cylinder 4 - 470 PSI

The powers there up to 50MPH, then it seems to be lacking.

When the engine ticks over it seams to be hunting slightly, i cant tell if it does it above tick-over because I cant hear it.

When the engine is revved the intercooler hoses baloon up, is this normal? I cant see any splits or delamination of the hoses, they did have oil in them. Which id expect.

When doing the compression test I noticed that the glow plugs on cyliners 2 & 3 seemed very oilly.

I changed the 3 holed head gasket in 2006 with another 3 hole gasket. This was done to try & cure an oil leak that seemed to be between the head & the block.

The fuel filter & engine oil are changed every 5,000 miles.

When accelerating hard it puts out a bit of smoke, but never had a problem on the MOT with emissions.

I cant tell if it's using any oil, as it leaks from the rocker cover like all 300TDi's ive seen. Theres no oil in the expansion tank indicating a dodgy head gasket.

Has anyone got any thoughts please.

Many thanks

[BogMonster]

OK first 2 checks probably not but worth ruling out as you feel an arse when you find them after spending lots of money: is the throttle pedal stop bolt in the right place (i.e. hasn't come loose) and is the adjustment on the cable correct at the pump end i.e. no slack in the cable? Both are not uncommon and both are often responsible for "power loss" complaints

300Tdi's do hunt sometimes at idle especially when cold - my new one (7000 miles) does it quite a lot, it varies between engines. Usually a sign of the idle speed being a bit low.

Hoses: depends on how much, a small swelling is normal (ooer) have you taken off the small right angled hose and checked it inside as well as outside? again this is often a cause and is invisible till you take it off.

Air filter OK?

How quickly did the power loss appear is it overnight or gradually over days/weeks?

[JimAttrill]

Oh no!

1) K&N filter should only be used on lawn mowers, not on Land Rovers (my favourite soapbox)

2) Zeus timing gears are most likely stuffed. See huge argument on this forum or else LRA forum.

[mpb]

Oh no!

1) K&N filter should only be used on lawn mowers, not on Land Rovers (my favourite soapbox)

2) Zeus timing gears are most likely stuffed. See huge argument on this forum or else LRA forum.

Take me outside & shoot me now.

Cheers BogMonster. Ill check those two points when I get five minutes.

The power loss has come on over a period of time, its not my daily drive so its difficult to pin point it in time, as it can sit for a week or two.

[bulletmp]

I WILL GET RID OF THE ZUES GEARS AS SOON AS POSSABLE!!!!!!!!!!!!!!!!!!!!!!!!!! Catch my drift, and check the fuel pump boost pype as mentioned,

[Adz]

It's not always the pipe... check the diaphragm in the top of the injection pump isn't stuck to the top plate - if it is you're only going to get 'off boost' fueling. Oil mist from the turbo gets carried down the advance pipe and sticks the diaphragm either to the top plate, or in the down position. If it's stuck down you'll get lots of black smoke which clears as the engine builds boost (and it'll go like a rocket off the line so this isn't likely to be the problem in your case, much more likely it's stuck to the top). Really simple to check and to clean... undo the 4 slot headed screws that hold the top plate onto the injection pump. It's normal for it to lift away slightly at this point. Carefully slide the plate to one side, try to avoid lifting it straight off so you don't disturb the position of the diaphragm and spindle relative to the fuel delivery needle. Once it's clear of the top of the diaphragm, note the position of the punch mark in the plate in the middle of the diaphragm and then carefully clean the diaphragm and the housing it sits in with some lint free cloth or paper. Realign the punch mark as it was before you took the plate off and put the screws back in. Shouldn't take you more than 10 mins all told. Test drive and see if that fixes it. PM me or e-mail me if you want a phone number to call me on to talk you through it...

Cheers,

[RRX]

Sounds very similar to mine when i 1st got it. Full service straight away with new fuel filter and cleaned out the sedimentor(not sure if the defenders have them). Then replaced lift pump and finally got the injectors overhauled. Get some decent injector cleaner and run that through over a few tanks and see if power starts to come back a bit, would point the the nozzles being blocked on the injectors. Also fit a nice paper filter and get the timing gears checked to make sure they aren't about to self destruct like alot seem to

[mpb]

Thankyou everyone for the advise.

Ill check the pump diaphragm at the weekend, as every time I get in from work its starting to go dark .

Im going to give the system a dose of Redex & take it for a good run, to see if that helps.

Im also going to try & have a look at the Zues Gears to see what state there in.

Ill let you know how I get on.

Thanks again

[m0bcg]

check fuel lift pump arm .

its common for the lift pump arm pin to break and then the pump wont work .

the engine will still run because the injector pump will draw fuel by itself, but you wont get high rev power due to lack of fuel .

i have a 300tdi defender and that happened to me last year .

if you buy a new lift pump and make sure you buy 2 nuts and 2 olives for the pipe fittings .

i cannot say for definate that its the lift pump but it is a common failure on the 300tdi , so is worth at least pulling the pump away from the block and making sure the arm and pivot are ok or not .

there is a plastic tee connection just by the injector pump diaphragm housing connection of the pipe coming from the turbo , check that the plastic tee is not broken .

when revving engine up , yes the hoses should pressurise once the turbo boost is there , but they shouldnt expand and bubble out , they will more or less stay same shape but just get stiff .

i know youve changed head gasket so that should be ok , and looking at the compression figures they are all ok and within spec .

i would look close at the diaphragm pipe from the turbo and make sure it pressures up .

best to change fuel filter first before any of above, just in case you have water in there or carp which will stop fuel passing through it readily .

i change my filter every 2 months at least , after all they are only a couple of quid each .

im not sure if it would be an issue but maybe look at the turbo intake , just in case its caked with black sticky oil at all .

cyclone filter on head might need a clean but i doubt thats anything to do with it .

zeus gears will probably be ok if the engine runs as normal , only thing it might be is if the pump timing has altered , ie the bolts on the injector pump pulley/gear may have come loose or something , i know its unlikely but still worth a thought .

if timing has gone retarded then engine will become quieter running and if advanced more it will make more noticeable diesel knock .

make sure valve caps are ok and valve lash is also right .

i think everyone here has covered all your possible areas to look at .

hope you get it sorted .

ian

[mpb]

check fuel lift pump arm .

its common for the lift pump arm pin to break and then the pump wont work .

the engine will still run because the injector pump will draw fuel by itself, but you wont get high rev power due to lack of fuel .

i have a 300tdi defender and that happened to me last year .

if you buy a new lift pump and make sure you buy 2 nuts and 2 olives for the pipe fittings .

i cannot say for definate that its the lift pump but it is a common failure on the 300tdi , so is worth at least pulling the pump away from the block and making sure the arm and pivot are ok or not .

there is a plastic tee connection just by the injector pump diaphragm housing connection of the pipe coming from the turbo , check that the plastic tee is not broken .

when revving engine up , yes the hoses should pressurise once the turbo boost is there , but they shouldnt expand and bubble out , they will more or less stay same shape but just get stiff .

i know youve changed head gasket so that should be ok , and looking at the compression figures they are all ok and within spec .

i would look close at the diaphragm pipe from the turbo and make sure it pressures up .

best to change fuel filter first before any of above, just in case you have water in there or carp which will stop fuel passing through it readily .

i change my filter every 2 months at least , after all they are only a couple of quid each .

im not sure if it would be an issue but maybe look at the turbo intake , just in case its caked with black sticky oil at all .

cyclone filter on head might need a clean but i doubt thats anything to do with it .

zeus gears will probably be ok if the engine runs as normal , only thing it might be is if the pump timing has altered , ie the bolts on the injector pump pulley/gear may have come loose or something , i know its unlikely but still worth a thought .

if timing has gone retarded then engine will become quieter running and if advanced more it will make more noticeable diesel knock .

make sure valve caps are ok and valve lash is also right .

i think everyone here has covered all your possible areas to look at .

hope you get it sorted .

ian

Cheers Ian,

Just had a look at the lift pump, this is looking like the suspect. Ive loosend the bleed screw on top of the filter and cranked it over. No fuel came out. I then worked the pump lever & I didnt get any fuel out. Ill go & get one in the morning & change it.

Many thanks

[jimmy_neutron]

Cheers Ian,

Just had a look at the lift pump, this is looking like the suspect. Ive loosend the bleed screw on top of the filter and cranked it over. No fuel came out. I then worked the pump lever & I didnt get any fuel out. Ill go & get one in the morning & change it.

Many thanks

It is possible that the injector pump will drag the fuel away (and air) quicker than the lift pump can provide fuel.

It is also possible that the little lever on the back of the lift pump does nothing. It depends on the lift pump cam position. You need to try the pump then turn the engine a bit on the bottom pulley then try again. Not saying its not the lift pump cos it probably is, just saw a possible flaw in your testing.

My money is on the injectors.

[JimAttrill]

And money is the right word. Always go for the cheaper options first, like the fuel pump. They don't last very long, unlike the injectors which do.

So my money is on the pump. If it isn't, at least you have a new one which is inevitable anyway.

[jimmy_neutron]

And money is the right word. Always go for the cheaper options first, like the fuel pump. They don't last very long, unlike the injectors which do.

So my money is on the pump. If it isn't, at least you have a new one which is inevitable anyway.

Reread what i said ... early mornings ain't my strong point.

Agree cheapest easiest option first.

However if it seemed to come on over a period, and pots 2+3 appeared oily in comparason to 1+4. There was something else i picked up on that made me say injectors.

If the injectors are the originals then they are due to replaced as 'routine maintenence'. However, if they have ever been changed then they are not. Maintenence is subjective though cos some people maintain when broken and others maintain to try to prevent failures.

I maintain regardless of cost because i don't want to find that i need to go and buy one of them new defenders with all them electronic gadgets that are waiting to go wrong.

Like Jim said though .. Injectors aint cheap.

£34 each from paddocks for genuine bosch ones i think. Need 4 of them though. There are cheaper places to go, its just finding them thats the problem. Prob save that back in fuel after a while anyway.

£18 for a lift pump. Definately worth doing.

Got a fence i can sit on ?

Let us know though.

[JimAttrill]

I put new injectors in at 160k (100k miles) and took them out again at about 170k as the engine didn't go as well! I now am on 261k and the new injectors are still in the garage in their boxes. Maybe I should try swopping them again some time.

[jimmy_neutron]

I put new injectors in at 160k (100k miles) and took them out again at about 170k as the engine didn't go as well! I now am on 261k and the new injectors are still in the garage in their boxes. Maybe I should try swopping them again some time.

Were they new or recon ?

Heard a few problems with recon injectors, but never new ones not being as good.

If they were bad uns first time, a few years won't of fixed them.

smoking on start up can be (amongst other things) a sign of worn injectors. Thus, if she doesn't smoke when she starts and drives ok throughout the range then your injectors are probably ok.

I ran a car till 200,000miles only changing the clutch once, oil+ filter changes, and brakes etc.

Never touched the pump or injectors. It ran on veggie mix for 100,000 of them miles.

My mrs wouldn't let me buy a new one cos she liked the old one. She said it was 'comfy'. Killing it was quite a challenge.

I like my landie though, so it gets whatever it wants

[simonb]

It's not always the pipe... check the diaphragm in the top of the injection pump isn't stuck to the top plate - if it is you're only going to get 'off boost' fueling. Oil mist from the turbo gets carried down the advance pipe and sticks the diaphragm either to the top plate, or in the down position. If it's stuck down you'll get lots of black smoke which clears as the engine builds boost (and it'll go like a rocket off the line so this isn't likely to be the problem in your case, much more likely it's stuck to the top). Really simple to check and to clean... undo the 4 slot headed screws that hold the top plate onto the injection pump. It's normal for it to lift away slightly at this point. Carefully slide the plate to one side, try to avoid lifting it straight off so you don't disturb the position of the diaphragm and spindle relative to the fuel delivery needle. Once it's clear of the top of the diaphragm, note the position of the punch mark in the plate in the middle of the diaphragm and then carefully clean the diaphragm and the housing it sits in with some lint free cloth or paper. Realign the punch mark as it was before you took the plate off and put the screws back in. Shouldn't take you more than 10 mins all told. Test drive and see if that fixes it. PM me or e-mail me if you want a phone number to call me on to talk you through it...

Cheers,

My 300 Tdi "felt" a little low on power recently, EGT was also 200 degrees c lower as well, despite boost still measuring 1.1 bar. Anyway got round to looking at it today.

Thought i'd start with the boost diaphram to see if it was split, takes cover off, and the rubber is well and truely stuck fast to the cover!!.

So although boost has been working ok, fuel has not been increasing as boost comes on as the diaphram can't move down and increase the fuelling. Fuelling has been entirely by throttle position.

So cleans top of cover and diapram - no oil mist but a bit of "dirt". Then to stop it all sticking again I give it a light dust with talc from the inside of my latex gloves.

A test drive proves normal performance is returned with EGT back where it should be..

[mpb]

Thankyou everyone for your advice.

I changed the lift pump & fuel filter this morning. There seemed more power & more top end speed. I couldn't give it a full test as I had the trailer on the back, but it pulled well on the hills.

When I get a free day, ill check the injection pump diaphragm.

Thankyou once again.