2.5d forth injector

[stew.g]

hi,does ayone know if the fourth injector is mapped to the cars ecu ?,or are they all standard?.

 

[bwarb]

hi,does ayone know if the fourth injector is mapped to the cars ecu ?,or are they all standard?.

Fourth injector ?

 

[stew.g]

the one with the lead on it that plugs into the loom.

 

[bwarb]

the one with the lead on it that plugs into the loom.

What model RR and engine are we talking about ?

 

[stew.g]

p38

 

[lanmjdun]

No, it doesn't need programming or anything clever like the TD5 injectors do.

 

[eightinavee]

No,its just a needle lift sensor to give the EDC ECU info about the start of injection.You can just replace it.

 

[bwarb]

No,its just a needle lift sensor to give the EDC ECU info about the start of injection.You can just replace it.

OK, I'm a little less confused now, it's not an injector at all then. Is it the equivalent of the CID sensor that tells the ECU whether the engine is on rev1 or rev2 of the four stroke cycle (i.e. the camshaft sensor) ?

Why is it referred to as the fourth injector ?

 

[lanmjdun]

It is an injector with a lift sensor. It tells the ECU when the injection cycle is happening compared to the crankshaft position - and that is the extent of my knowledge on that subject!

 

[eightinavee]

It is an injector with a lift sensor. It tells the ECU when the injection cycle is happening compared to the crankshaft position - and that is the extent of my knowledge on that subject![/quote Yep,when the injector commences injection it squashes a piezo crystal which outputs a small voltage - can be viewed on a scope.The engine ecu uses this info along with the 36-1 waveform from the crankshaft position sensor to calculate actual injection timing and can advance or retard the pump timing.This is after comparing other sensor values such as coolant temp,boost pressure,driver demand etc,etc.
It is also used in the event of the crank sensor failing,which results in a high idle speed as it is not as accurate as the crank sensor esp on overrun as fuelling is completly shut off.
B.T.W. Stew,why are you replacing the injector ?

 

[stew.g]

im changing it as iv swapped the engine and its running like a bag of ****e,on tickover its like its running on bout 3 cylinders,i know the engine is fine as i drove the donor car for bout three months to avoid this situation ?!?!,the fourth injector is the only thing i didnt swap,am i clutching at straws here or could it solve the problem?,any advise would be grateful.

 

[eightinavee]

Without hearing it running its difficult to say what is wrong,if it is only on 3 cyls then changing one injector is not going to help.If the needle lift sensor has failed on your existing injector the engine should still run on 6,albeit not at 100%.I think you need to get some help from a decent diesel person,if you have a Bosch injection specialist near you they would be the ones to ask.Although your car may not seem that old,not many people have much product knowledge with Bosch EDC and the majority of cars now are common rail,so finding the right help may not be easy.