td5 cold missfire, unburnt fuel smoke

Hi, not long bought a td5 disco, 108k miles, all fine, there was a small fuel leak from the fuel presure regulator, which i replaced and since ive had a missfire and diesel smoke when the engine is cold, also top end noise which i hope is diesel knock, any one had simular before i start throwing money at the wrong area, had thought it may be a problem with the fuel pump, help please

when you replaced the fuel regulator did you follow the fuel priming info which is in the hand book under run out of fuel because it sounds like you have a air lock in the fuel system, it won't clear it unless you follow the priming procedure.

Scotty

Hi,thanks, it came without a handbook, is it a simle procedure, is there anywhere on here where i might find it,

Peter_h said:

Hi, not long bought a td5 disco, 108k miles, all fine, there was a small fuel leak from the fuel presure regulator, which i replaced and since ive had a missfire and diesel smoke when the engine is cold, also top end noise which i hope is diesel knock, any one had simular before i start throwing money at the wrong area, had thought it may be a problem with the fuel pump, help please

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I think you need to start thinking that you need to change the copper washers sealing your injectors from the combustion chambers.

I suggest it is probable one of them is leaking (I have been through this myself) allowing a bit of fuel to seep into a cylinder when stopped (thus black smoke on start-up) and when the engine starts, the leak is passing some GAS up into the fuel gallery, causing a misfire because there is gas in the fuel being fed to at least one of the injectors. If I had to guess, I would guess one of the front two injectors.

This IS a DIY job, and you'll need 5 new copper washers, 5 new O-rings, a cam-cover gasket if you can't be bothered to use the old one (I did), and some sort of little suction device like a 20ml syringe with 6 inches of washer tube on it. You will also need a really accurate digital caliper. It will need to measure to one thou 0.001". You will need a Stanley knife to take the old washers off the injectors tips. A quality set of small sockets, a good torque wrench, and a pry-bar with a right-angled end to lever the injectors up and out. I had all of mine out and back using NO special tools.

The injectors MUST be replaced in the same holes where they came from. It is ABSOLUTELY ESSENTIAL the new copper washers MUST NOT be any thicker than the ones you take out. This is very important. If you get this right you will not need to touch the injector rockers screws.

If you want to tackle the job, and need to hear my experiences, feel free. Mine was done a year ago and about 15k miles and hasn't missed a beat since.

CharlesY

Peter_h said:

Hi,thanks, it came without a handbook, is it a simle procedure, is there anywhere on here where i might find it,

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1. IGN ON. Leave IGN on all the time during this procedure - do NOT turn off and on.
Driver's door wide open so you can hear the pump running.

2. press throttle pedal to the floor and let it up - do this FIVE times. The pump will start running. Wait till it stops. LEAVE IGN ON !!!!!

3. Repeat stage 2 as many times as you like.

4. Listen for a change in pump noises. Sloshing squealy noises are bad. Gentle whine is OK.

CharlesY

Hi, thanks to all for the advice, have now primed fuel system but no difference, and have ordered a full set of injector seals, makes sense really as now after replacing leaking pressure regulator, therefore increasing fuel pressure has resulted in more pressure in the fuel rail, so if any seals were just coping before just cant do so now, i also think the oil level has increased, which can only be caused by diesel getting into the sump, again thanks to all and will report my results later,

Peter

Peter_h said:

Hi, thanks to all for the advice, have now primed fuel system but no difference, and have ordered a full set of injector seals, makes sense really as now after replacing leaking pressure regulator, therefore increasing fuel pressure has resulted in more pressure in the fuel rail, so if any seals were just coping before just cant do so now, i also think the oil level has increased, which can only be caused by diesel getting into the sump, again thanks to all and will report my results later,

Peter

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Do you have cofidence that you can tackle this job?
Provided you take a few precautions all should be well.

The injectors must go back in the same holes they came from.

You MUST suck out all excess fuel from the piston crowns.

You must make the recess in the head and the injector ends perfectly clean.

A Stanley knife is a good tool for getting the old washers off.

You will easily spot which injector(s) leaked gas as there will be clear signs of black carbon on the washer faces, and hard coke where the inner hole of the washer surrounds the injector nozzle.

The NEW COPPER WASHERS MUST NOT be thicker than the ones you take out, not even by as little as 5 thou 0.005" . If you achieve this there will be no need to adjust the injector rockers. A little thinner makes no difference. They should be very close to original as they come.

You should very lightly de-glaze the new copper washers both sides by one or two wipes up a very fine perfectly flat sharp file. 'Cross-hatch' them a tiny bit at 90°.

RAVE is quite good on this job but rabbits on about special tools. You won't need any if you are reasonably handy.

Good Luck!

CharlesY

Hello,

Progress report on my unburnt fuel issue, replaced all injector seals, re-set injector clearances and has improved the problem slightly, although still on checking (after buying a nanocom) there is still a cylinder imbalance from -1 to +7-8 between cylinders, this gets worse on gradual throttle pressure up to around 2100rpm (-11 to +9 accross all cylinders) then the engine will suddenly run a lot smoother and the cylinder balance is between -1 to +4 varying across all cylinders which i believe is within tolerences.

Im wondering if i have a fuel pressure problem with the submersible pump, or an air metering problem although this seems to be reading airflow on the nanocom, and all other readings as in temp sensors etc seem ok too.

Any more suggestions from this place of immense knowledge

Peter

surely if its a fuel pressure problem, your problem would get worse as fuel demand increases? sounds very much to me like an injector is playing up or one of the inputs to the ECM is varying. you still running with yer EGR in place?

Hi, yes did think that, was hoping it wouldnt be an injector, all the connectors are clean and well sealed, and yes egr is still in place, whats the benefit of removing it?

mine was jammed open, and was running really up to s**t. i completely removed the EGR and blanked off the exh manifold and noticed immediately it was much more responsive to throttle input, especially when cold. only drawback i can see is takes slightly longer to warm up...no big deal.

have you checked out the plug at the ECM...the red one? give it a good squirt with electrical contact cleaner. i had a very similar problem, but was found to be oil ingress into the injector loom, and all the way down to the ECM plug. not sure where the disco's is tho [mine a Def]. number 3 injector kept showing up as open circuit. i replaced the injector loom, but added my own blob of high heat sealant on the plugs at the injectors....problem solved [so far]. how did you set the clearances on the injector followers?

well suck me sideways, problem solved after it became terribly worse, today the poor disco coughed and spluttered to a halt, got it home and found one cylinder full of diesel, on inspection after yet again removing injectors, number 2 injector copper washer obviously leaking, got a set of new washers, this time genuine ones and found their just that little bit a better fit, previous ones, bought from bearmach dont actually fit the base of the injector properly and miss the outer seating part of the injector !!!

So today has been spent first recovering the disco home, stripping down the top end, getting loads of fuel out of the engine, rebuild and re-setting, then the marvellous sound of re-starting, took a couple of miles to clear the wasted fuel in the exhaust, but now have fairly well balanced injector values !

Now im off for a pint or three and wait for some white stuff down here to play with

Hi bushtoy, to set injector clearances, turn cam untill injector is fully compressed,slacken locknut then turn adjustment screw down untill you feel it bottom out then turn screw back one complete turn, then tighten locknut, repeat for each injector, simple job really

Peter

Peter_h said:

Hi bushtoy, to set injector clearances, turn cam untill injector is fully compressed,slacken locknut then turn adjustment screw down untill you feel it bottom out then turn screw back one complete turn, then tighten locknut, repeat for each injector, simple job really

Peter

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Remember, you may not need to do this at all.
The clearance is not critical as long as there is clearance.

If you pay attention, you should be able to avoid touching the adjusters.

When changing copper sealing washers it is VITAL to measure that the NEW washers are NOT THICKER than the old ones. If they are thicker, the whole injector will sit HIGHER (closer to the cam) and may remove all clearance, and that could easily end up destroying an injector.

If the new washer is the same thickness or a tad THINNER, there is no need to touch the rocker adjusters at all.

LR say to buy new rocker adjusters and nuts if you undo them.

If you can avoid interfering with the adjusters, I recommend it.

CharlesY

Hello CharlesY

I have done it, its a pretty easy procedure, theres no mention in landrovers own main dealer workshop manual of replacing the adjuster screws or nuts,we never changed any nut or screws on all those ohv engined cars we owned and serviced in the past, the point im making for reference and for others not to have the same consequeces as me is having the correct diameter washer is far more important than thickness, as i found to my cost today, boomin bearmach!!!

Peter_h said:

Hello CharlesY

I have done it, its a pretty easy procedure, theres no mention in landrovers own main dealer workshop manual of replacing the adjuster screws or nuts,we never changed any nut or screws on all those ohv engined cars we owned and serviced in the past, the point im making for reference and for others not to have the same consequeces as me is having the correct diameter washer is far more important than thickness, as i found to my cost today, boomin bearmach!!!

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I think you didn't see the relevant section clearly ... they DO say changing the adjusters and nuts is part of the job, and with good reason.

from RAVE
Refit
1. Clean rocker shaft and mating faces.
2. Fit NEW rocker adjusting screws fully into rocker
arm. Fit new lock nuts to screws but do not
tighten.

LR recommend you UNDO the rockers crews fully, and explain why - to prevent damaging injectors on re-fitting.

Believe me .... if you didn't do that, or do what I described, then you have been LUCKY not to have destroyed the injector(s) you fitted new washer(s) to.

Now watch this next piece ....

THE THICKNESS OF THE WASHERS IS ABSOLUTELY CRITICAL.
THE NEW WASHERS MUST NOT BE THICKER THAN THE OLD ONES.

I don't think you yet "see" what happens if the injector sits up a tiny bit higher. The higher the injector sits, the less clearance there is, until there becomes NO clearance ON FULL DOWN STROKE. Basically the inner plunger of the injector gets blasted down into the injector body, but because there's no clearance now, it hits the bottom, keeps going a bit, and destroys the injector first revolution of the engine.

People changing injector washers are taking a terrible gamble if they just change them and ignore the clearances. Believe what I wrote above, and disregard anyone who says it doesn't matter ....

CharlesY

CharlesY said:

I think you need to start thinking that you need to change the copper washers sealing your injectors from the combustion chambers.

I suggest it is probable one of them is leaking (I have been through this myself) allowing a bit of fuel to seep into a cylinder when stopped (thus black smoke on start-up) and when the engine starts, the leak is passing some GAS up into the fuel gallery, causing a misfire because there is gas in the fuel being fed to at least one of the injectors. If I had to guess, I would guess one of the front two injectors.
CharlesY

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Sorry to butt in but this is a very interesting thread as I think I have that same problem (Def 200tdi), black smoke on start up. I noticed when I changed my glow plugs, one was pretty wet (No.1 from front)



Is this normal and should I think about changing the washers?
The other 3 had some soot on them.
Many thanks

Your 200 tdi problem has absolutely nothing in common with the TD5 issue under discussion.

The top glowplug is a new one. If the bottom one came out looking like that you may need a new piston and rings, or maybe a new cylinder head, or if you are lucky just a head gasket.

CharlesY

CharlesY said:

Your 200 tdi problem has absolutely nothing in common with the TD5 issue under discussion.

The top glowplug is a new one. If the bottom one came out looking like that you may need a new piston and rings, or maybe a new cylinder head, or if you are lucky just a head gasket.

CharlesY

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Thanks for that CharlesY Just with all this black smoke stuff going on, I'd just thought I'd ask. Cheers

Well the car now runs fine, new seals and genuine copper washers,which are designed to fit by landrover, common sense told me to slacken the adjusters before refitting the rocker shaft, however, thanks for all the advise

Regards

Peter