OK, so I'm a plonker............

[...]

Wikipedia has a useful short article that will answer your question - I will leave you to Google for it :-)

No.

Chris

Nor me in 42 years. Oh, wait... I've never driven a diesel :-)

Chris

Yes. That's why alot of them failed when low-sulphur diesel became the norm.

Manufacturing tolerances, and injection pressures. A typical conventional diesel would run somewhere around 150-250 bar injection pressure. A current thrid generation common rail injection system runs anywhere from 150bar (minimum required for the injectors to even open) to any where upto 2500bar and ever increasing pressures. The older systems could tolerate a slight lack of lubrication breakdown better than modern systems, but the tolerances in modern systems are that tight (currently running in the region of 2 microns), that the slightest bit of contamination/wear can be detrimental to the performance.

From in the field experience, I've only ever seen one pump failure that could be directly attributed to mis-fuelling (car was mis-fuelled twice within the first 10k, and the pump failed about 20k). I've seen far more pumps/injectors fail on vehicles that have never been mis-fuelled. Modern diesel injection systems are not the most reliable of systems in the first place, so manufacturers will use any excuse to invalidate warranties.

But even if anything fails, it probably won't fail immediatly, so do you pay a large amount up front to replace all the components, or wait until something actually fails, which it might not do, before replacing it?

I am not too fay with the workings of injection pumps, I was told to leave it alone, set my own timing, valve clearances, pretty much anything else but DO NOT touch the injection pump I was told, so I didn't. So I still cannot understand why the lubrication is so important, I can understand the tolernaces, but until I get in and study a pump I'll be quite blind. I'll have a search. Thanks for the full response all the same, I'm sure it'll mean more to me when I know more.

Is there any way of testing it or having it checked/self check/clean?? At

2500 bar I suppose nothing could clean it better than the diesel going through it...

Why not rip one off a scrap yard car and pull it to bits?

:oD Good idea. Roll on 2007.

I'm contemplating buying a second hand 'ECU'd' car and ripping the wiring out and starting again without the black box, just for the experience and the fun.

Any thoughts?

Injection pumps have a lot of metal on metal moving parts, so any breakdown in lubrication means metal rubs directly on metal with disastorous effects (with tolerances of 2micron, it only has to touch once for it seize/become out of tolerance) Off course, the newer the system, the smoother the moving parts are so they can work with less lubrication, but they obviously still rely on having some lubrication. But older systems worked on lower pressures, so lubrication levels could drop pretty low before damage occurs, but newer systems run higher pressures, so any failure in lubrication results in damage far quicker.

With a special tester. It's essentially an electronic pressure sensor (I've never came across any mechanical gauges that can withstand 2500bar) and meter, which you put in place of the main pipe to the fuel rail, you stick

12 volts to the fuel pressure regulator to keep it shut (only if it's directly on the pump - some are on the fuel rail), and crank the engine over. Off course, you'll never get the full pressure at cranking speed, but it'll still give you an indication that all is well with the high pressure pump. For maximum injection pressure, you've got to read the ECU data stream with the engine under full load.

It won't work.

Second generation diesels (fly-by-wire pumps), rely solely upon solenoids in the pump to control timing and injection quantities.

And third generation diesels (common rail systems), need far more electronics. Fuel pressure is electronically controlled, and the injectors need upwards of 60volt to fire them.

Coo. Twice the tolerances Citroen managed for the DS hydraulic system in the 1950's. Still, I suppose the rest of the industry might catch up some time ...

Ian

This is sad, I do hope the MoD do not employ these new types. If something goes wrong on my diesel I can fix it, except a fault with the fuel pump of course.

Or about 20 times that of an old diesel pump :-)

Millions of people manage not to put the wrong fuel in a car.

Fuck sake, talk about grabbing at straws. Is this the best excuse you can come up with? THERE WERE THREE NOZZLES ALL CLEARLY MARKED.

Yes, they do, and FWIW I've never put the wrong fuel in a car/van, but people also have off days - days where any number of other worries on their mind somehow take precedent over picking up the corrent pump nozzle and bingo, wrong fuel in tank. Shit happens.

There are only two types of people who never make mistakes, first are those who never do anything anyway, so can never gat anything wrong, Then there is the group who are always in the position to "delegate the blame". To err is human, to foul things up completely also requires a computer. I am relieved to say that to date none of my family have managed to do this one either, but none of us are perfect, apart from perhaps one poster here.

And I wonder how many motorists would then drive off leaving their cap stuck to the pump? The headline on that site does say, according to an RAC poll, that 1 in 7 motorists have made the mistake of misfuelling.

I'm absent minded and own a petrol + diesel cars, so if I suspect I'm having an "off day" I compensate by checking the filler cap label and the pump label twice!

I was suspicious about a little country garage in Devon where the markings on the pump were less than clear so I asked the cashier - nearest I ever got to getting it wrong - but that's not to say I won't ever. I will almost certainly notice before I leave the garage though, so hopefully I'll merely get laughed at by the AA bloke rather than get an expensive bill ;->

Merry Christmas :)

Timbo

Gotta laugh - the 6 mth old CLS I had last week had "diesel" inside the flap and around the filler. The new E class has a red filler cap with "Diesel" on it. The hire documents had a bit to sign to confirm I knew what fuel to put in, as did the sale agreement on the one I bought.

It's an easy, but expensive mistake, and the main reason I changed both our cars to diesel at the same time. Being tight / skint helped too.