TD5 Injector question?

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4x4forks

Member
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98
Can any one tell me why the injectors have to have a serial number programed into the ecu? Also what would happen if this was wrong.
I recently had my injectors out and tested but befor they went away I wrote down the serial numbers and the cylinders that they came from. I sent the disco into a dealer to try and solve my problem and in serching for the problem they informed me that two of the injectors were in the wrong place. Now the truck is back it seams flat and not what it was befor it went away. Any advise would be good . Injecor loom New and Boosting ok, No egr valve .
 
Can any one tell me why the injectors have to have a serial number programed into the ecu? Also what would happen if this was wrong.
.

Because it works like that:

Electronic Unit Injector(EUI)
The EUI's are located in the top of the engine inside the camshaft cover. There is one EUI per cylinder. They inject finely atomised fuel directly into the combustion chamber. Each EUI has its own electrical connection, which is linked to a common harness also located under the camshaft cover. Each of the EUI has its own 5 letter grading code. This code is used so that greater EUI precision is achieved.
The ECM provides the earth path for the EUI. Using an injection-timing map within its memory and information from the crankshaft speed and position sensor the ECM is able to determine precise crankshaft angle. When the ECM determines the crankshaft speed and position it closes the spill valve within the EUI. Fuel pressure rises inside the EUI to a predetermined limit of, 1500 bar (22,000 lbf.in
2 ) on pre EU3 models, and 1750 bar (25,500 lbf.in 2 ) on EU3 models, at this limit the pintle lifts off its seat allowing the fuel to inject into the combustion chamber. The ECM de-energises
the spill valve to control the quantity of fuel delivered. This causes a rapid pressure drop within the EUI which allows the EUI return spring to re-seat the pintle ending fuel delivery.
The electrical circuit that drives the EUI works in two stages depending on battery voltage. If battery voltage is between 9 and 16 volts the EUI's will provide normal engine performance. If however battery voltage falls to between 6 and 9 volts, on pre EU3 models, EUI operation is restricted to a limit of 2100 rev/min, on EU3 models EUI operation is restricted to idle.
If the vehicle is fitted with a new ECM, the EUI grades for that specific vehicle must be downloaded to the new ECM using TestBook. In the event of the engine failing to rev above 3000 rev/min it is probable that the EUI grading has not been completed.
 
I 've got Navcom and Just took a guess and changed 2 and 3 data over and it has made a big inprovement. Smoother and more power . So it looks like the dealer changed over data for no reason. But I still don't know why is it so importent and what effect it has having the wrong numbers in the wrong place? cheers to all .
 
because each injector will have a slightly different opening pressure and flow rate - the ECU needs to know that info in order for it to be able to accurately meter the fuel

uncoded injectors will work, but properly coded injectors will work much much better
 
I've arranged to take my 2000 Td5 over to Bell Auto Services in mid June for a re-map. So prior to that I've been doing little outstanding jobs to get it ready, FPR leak etc. One of the things I've done is plug it into my friends Nanocom to check for faults.

What its turned up is that Nanocom is saying that all 5 injectors have the same code. Apparently this is as likely as winning the lottery ....

They have been recorded as:

INJECTOR1: NC NC 0-M-A
INJECTOR2: NC NC 0-M-A
INJECTOR3: NC NC 0-M-A
INJECTOR4: NC NC 0-M-A
INJECTOR5: NC NC 0-M-A

I Got time to pop the cylinder head cover off today and jot down the injector codes... they are all different.

Each one has the 5 letters that you feed into Nanocom and also a large single number on them too, not sure if that is supposed to correlate to which cylinder its in? if so number 5 would be at the front and has been changed ? ? ..

Reading from the back of the engine to the front:

1 NGBBA
2 NCLBA
3 LFGFA
4 NMNNA
1 NCLCC

Can anyone confirm which cylinder on a Td5 is no.1? I thought it was the one at the front - but this makes me wonder.

I'm also curious as to how the codes ended up being all the same ... ? I wonder if it was a new ECU and that was the default?
 
That info is good. My Nanocom readings are all different. By comparing your injector numbers then the first 4 letters fit in the first 2 boxes.
IE NGBBA will become NG BB 0-M-A
NCLBA NC LB 0-M-A

My numbers are all simila to yours with the exception of one. NC DD 2-F-B.

I've been playing with the figure position and I've got my power back but it seems lumpy at idle. If I move other figures then I can make idle smoother but loose acceleration at the bottom end . I will have to remove my rockerbox and have a look . Where are the numbers located on the injector? I managed to find numbers 01566BU . these run in series 1-5 . Ive always been told that number 1 cylinder is nearest the water pump.
 
The code is easy to find on the top of the injector - looks like this (picture taken from ebay):

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For mine the plot thickens - the part number recorded through Nanocom is NNN000120 - ie the later flashable ECU.

So my guess is that mine has had a new ECU, the later type, and that's why the injector codes are as they are.
 
TD5 At last!! It works.
Taked the rocker cover off found the right letter codes and reprogramed via Nancom. Now she runs like it use to. The indy dealer had moved part of a code not the hole code which upset the poor thing.I have found out that for a code of NCLBA the first 2 letters go in as they are and the last changes. For black top injectors A= 0 or 3 B = 1 C= 2
Also for information fuel pressure can be measured via the removing the fuel temp senderand fitting a pressure gauge. Thread size M12 x 1.5. This should measure 4 Bar or 58 psi . Leave the temp sender connected so you won't get a fault code . Thanks to all who helped with posts.
 
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