Thread: fuel issues?

Originally Posted by wacoaus

Just checking on here for thoughts before I buy a new fuel pump for 99 disco 2 td5.
The fuel pump has always been a bit noisey but recently when I was driving to work , i pulled up and went around the back to get a drink out and it was realy noisey, drove rest of way to work and it ran fine.
Once there i had to start it to move it and it wound over a fair bit before it started and then the m and s lights came on and was running like a broken chaffcutter.
the next day i started it up and fuel pump clicked and ran silent but it started instantly as normal and idled perfectly but the second i touched the accelerator it started running rough ( missing cylinder) and belching white smoke as if raw diesel passing through the system and keeps belching smoke up through the revs even when the revs get right up and runs smooth still has the huge amounts of white smoke.
Shouldnt be the injector seals or washers as they were only done about 10,000ks ago and no oil in harness and not using oil or coolant.
I believe it is the fuel pump because of the noise but symptoms dont seem right to me (but i am no mechanic)
any thought would be appreciated as my first step at the moment is to order a new fuel pump

The white smoke is a worry as it may not be unburnt fuel but may be oil if it is not steam. Be very careful as you don't want to hydraulic a cylinder and bend a rod. You may have a head or gasket failure as I don't think the pump will cause all those symptoms unless you have contaminated fuel.
Nick

the noise from the fuel pump could be cavitation, unless it is a cheap replacement fuel pump that is in your Disco as they often fail by the bushes firstly getting noiser.( VDO are the only ones to get now)
There could be a blockage on the fuel line, sometimes the lines can get squashed above the fuel tank and body . The fuel filter air bleed valve could also be a source. Sometimes replacing the fuel filter can stop the noise also. There is no oil in the harness you report, but what about in the injector loom? . Check your MAF also

Thanks for that but I dont think it is oil as the amount of smoke is huge and dipstick looks fine , oil looks good and not using any at all and not losing coolant either,

Originally Posted by Roverlord off road spares

the noise from the fuel pump could be cavitation, unless it is a cheap replacement fuel pump that is in your Disco as they often fail by the bushes firstly getting noiser.( VDO are the only ones to get now)
There could be a blockage on the fuel line, sometimes the lines can get squashed above the fuel tank and body . The fuel filter air bleed valve could also be a source. Sometimes replacing the fuel filter can stop the noise also. There is no oil in the harness you report, but what about in the injector loom? . Check your MAF also

Thanks yep checked the loom at head plug and at the ecu no oil.
I suppose I am focused on the pump as it has been noisey since i bought it 3 years ago but the other day it was screaming just before the problems started and now it is back to its usual noise but I have not driven it anywhere except onto a trailer to bring home because of the clouds of smoke it just seems strange that if pump was stuffed in my mind i shouldnt be able to rev it up ( shouldnt even start) its just the smoke and the running rough if it is idling you wouldnt know any difference at all

Dunno tech stuff such as what causes white smoke, and stuff like that, but I recently helped to sort my brothers Td5 a few weeks back.
Firstly, he had very random rough running issues for a few months(after we gave it a service and changed the injector loom).
The issue would come and go, so it was hard to locate an issue, as when something was checked, it sorted itself and you'd thought it was fixed.

The just prior to a weekend away it started running rough again so we had to have a look.
First thing we thought was fuel pump too.
Then we discovered a very hard to see slow fuel drip from the fuel pressure regulator.
Changed that, then starting and running issues got worse.
Lots of white smoke when it ran rough.
We thought we stuffed up the FPR fitment, so re-did it again, same issues.
Fuel pump made noise, but nothing untoward.
Changed fuel pump, same issue.
Lots of head scratching later, I thought ECU issues so we decided the next day I'd take it to a specialist to have it checked.
In the meantime I drove it a bit more, and thought to remove ECU and open it up to have a peek to check for obvious burned out bits, or dry solder joints and stuff like that.
Sprayed all plugs with contact cleaner ... except the plug at the head from the injector loom, to the ECU loom at the front of the engine.
On the way to the LR specialist, the car sorted itself out .. that is no power loss, ran smooth idled smooth, and started fine.

More head scratching.

So decided for brother to drive it a bit more before we took it to the LR specialist.
He had a couple more random occurrences of the problem, and I told him what I'd done and suggest for him to remove that injector loom to ECU loom plug and give that a spray and check the pins and give it another spray.

Since that spray/pin checking that he did, no issues at all with the way it runs.

After all the $s he'd spent trying to sort this rough running/lack of power problem, it (so far) turns out that the new injector loom has some connection issues at the plug(at the head).
So the first thing, easy to do is to triple check it, spray it with WD/CRC/contact cleaner and check the pins for straightness and easy stuff like that.

When I had the TD5 for a short while, the one thing I noted when it ran rough was that the injector balances reading on the Nanocom were all over the place.
When it runs well, the balances usually display values of between -5 and +5 and don't change all that quickly.
When it ran rough, the values would be anywhere between -20 and +15(that I could take note of whilst driving), and changed much more rapidly.
Do you have a a nanocom, or could you locate someone with one?

If you know it was not ever changed replace the air bleed valve in the rear wheel side port of the fuel filter head, that's something to be ruled it out cos it's a known cause of noisy pump and hard starting, i've seen cases when it caused running issues too, google out WJN500110 ... if you change it run a purging sequence after that

well new fuel pump , new fuel air bleed valve, new fuel filter new maf and no change. does this after sitting overnight until you get the revs up it. take it for a 30 k drive with no smoke showing out the back in mirrors then you can stop it and leave it sit for an hour , start it and not a speck of smoke leave it overnight and this returns

I would be revisiting those injector seals.

Paul.