Do cdi injectors need programming?

[haydar]

Hi there

I've read in a number of places on this forum that replacing injectors needs 'programming' into the system!!! Is this true? I've just bought a complete set of injectors from Germany. After I fit them do I need to get them programmed?

Please advice.


Regards

 

[Flash]

I very much doubt it...

 

[jaymanek]

No way!

 

[Dieselman]

IIRC there are different resistances for injectors but as long as you have the correct ones then they should be plug and play.

 

[ManJ]

Plug an play all the way...

 

[mioba]

NOT A CHANCE

 

[spitzkop]

YES THEY DO!

Sorry to shout, but each injector has a flow rate stamped on them. This flow rate number must be programmed into the ECU, otherwise you will have fuel imbalance between the cylinders. I have my own programming kit and I have played around with the flow rates to get more power, but if you get them wrong, all sorts of nasty knocking noises come from the engine at tickover/acceleration!

 

[se97mlm]

YES! The system is called IMA/ISA. Each injector is corrected for delivery at several pressures. In this way all injectors will perform exactly as a reference injector. It is easier to programme a correction into software than increase tolerances still further in production - they're already in the region of microns.

Each injector needs to be correct to +-0.2mg otherwise emissions and noise would be terrible - the pilot is about 1,2mg and this could disappear making the engine very noisy in comparison

 

[television]

Common rail systems run at around 280bar and the injectors only open 0.04mm, where the injectors are numbered these numbers must corrispond to that cylinder ECU map setting, this is why you cant interchange them.
the firms that recon them at a fraction of the price of a new one try and keep the coding the same where possible.

Just to let you know about the new piezo injectors. Piezo is a crystal that was used for pick ups on the old record players, the movement of the stylus in the record groove produced a voltage across the two opposite corners, with piezo if a voltage is applied to the corners,the opposite end gives a mechanical movement, and when used with injectors, it can open the injector 10 times faster than the injectors used today.

Malcolm

 

[Parrot of Doom]

Blimey Malcolm, I hope you're not still using a piezo-electric cartridge on your turntable The rest of the world has been using moving magnets and moving coils for a very long time

 

[television]

Blimey Malcolm, I hope you're not still using a piezo-electric cartridge on your turntable The rest of the world has been using moving magnets and moving coils for a very long time

Thank you so much and there is me thinking that MC stood for "middle class" music

Malcolm

 

[spitzkop]

So many cross overs here now..... (from the otherside that is.... or is that other club)!!

Why the same names, why not Television = Video Recorder?

If Malcolm wants to stick to the old tried and trusted technology of Piezo Electric Styli... why not.... I think MC is a little dated these days.... whats a vinyl record anway?

 

[DrNick]

As an aside, vinyl is also mildly piezoelectric. Probably not the best material to make LPs out of. (Not the best material for making injectors out of either!)

Nick

 

[television]

So many cross overs here now..... (from the otherside that is.... or is that other club)!!

Why the same names, why not Television = Video Recorder?

I thank everyone for their groovy comments.
Why the names ? I use the name Television on all 4 main MB forums, that way if I make a boob,everyone knows it is me, I do not use Video Recorder as its on the way out, and at this point in time in posting this,I am alive and kicking.

Malcolm

 

[se97mlm]

Common rail systems run at around 280bar

Malcolm

Hmm, a little more than that! THe earliest CDis operate up to 1350 bar, the newer ones 1600 bar, and the ones we have in development 1800 and 2000 bar. 2000 bar is only 29000psi!

 

[Dave K]

2900 psi. Pah, that's nothing. I work with 3500psi of Hydrogen. I don't fancy any leaks in that pipework.

 

[se97mlm]

29000

Indeed, if an injector were to squirt on you, if would be very painful indeed (life threatening in fact)

 

[spitzkop]

One of the sad facts about all this is that Diesel becomes as dangerous as Petrol! One of the great things about diesel is its safe until its relatively high flashpoint of around 55'c (forget exact flash point). Perhaps where going to start seeing American films with diesel cars which go kaboom because Clint Eastwood shoots a bullet into the engine

 

[Dieselman]

One of the sad facts about all this is that Diesel becomes as dangerous as Petrol! One of the great things about diesel is its safe until its relatively high flashpoint of around 55'c (forget exact flash point). Perhaps where going to start seeing American films with diesel cars which go kaboom because Clint Eastwood shoots a bullet into the engine

Sorry I don't follow your idea here.
True the fuel is vaporised so it yeilds more enrgy when burnt but the flashpoint is the same.

You can't ignite diesel with a flame, you need a wick to evaporate it.

 

[spitzkop]

Sorry I don't follow your idea here.
True the fuel is vaporised so it yeilds more enrgy when burnt but the flashpoint is the same.

You can't ignite diesel with a flame, you need a wick to evaporate it.

The process of compressing diesel to increase the pressure increases the temperature (it is cooled). Once you rupt the high pressure rail, the engine wont stop immediately, and so the crank driven pump will still continue to pump more high pressure fuel. Once the fuel has mixed with air, it becomes explosive. Ive seen this on a simple Eberspaecher Airtronic D4 heater, where a vapour diesel+air mixture has exploded, and thats at a fairly low pressure. With a high pressure, the whole engine bay will be filled with diesel/air vapour, creating a fuel/air bomb, the kind the americans use to wipe out people!! (I think its kerosene the Americans use, which is a lighter oil (diesel is constituted with lighter oils). Diesel engines work on a principle of self ignition, ie. Compress the fuel high enough, mix air and it will self detonate.

There was also an article on the other forum about an ML going up because of a single injector leak!