Diesel Injector with Sensor, Which One?

Sorry I can't help with the numbers but you can unplug it.
Mine failed as well but once unplugged the DDE doesn't get a signal, you will get an injector symbol on the dash and the DDE will default to another value - I could not even tell the difference.
I would still change it to get rid of the fault light but at least you loose the urgency.

Why do you need to change it ? They are an expensive but reliable item,so it helps to be sure its faulty.

Well,

I have this dreaded problem that the engine starts shacking & vibrating violently when at idle. This happens when I'm traveling for some time i.e say like more than 30-45mins. When the engine is running over 1000rpm this doesn't happen. But once it drops down the vibration starts. I've read some posts earlier and this is told as the 'Limpy tick over' IIRC.

Also i took the vehicle to the dealer, and i saw that when this shake comes, they loosened this injector (i.e injector no 4). Then the vibration got to minimal-none point. So obviously this is causing a fault. Also many have told this injector is one of the causes for this issue.

So i'm thinking about replacing this really soon as i'm quite afraid that i might damage the mounts or bolts somewhere.

Thanks fellas.

before going to a lot of expense check the bottom pulley (end of crankshaft) it has a built in cush drive/shocker what ever you want to call it. I had same problem when hot at tick over it sounded like a bag of spanners replaced lots of bits before finding out what it was when it finely gave up. the part No is STC3345
Tony

I have just had all my injectors overhauled as they were all "f^&*%d" apparently and that was with the car running fine with the odd - one every three months - of it idling roughly.

so before buying new one why not get the original overhauled?

cheers

Overhaul means repaired?

here we use a different term. We call it compressing the injectors. Yes i did compress the injectors & serviced the fuel pump. Still no success in getting this rough idle sorted out. Only a single injector has been replaced for the last 11 years, according to the dealer's records.

Will have to look into this more.

Thanks.

Go back to what I said before; unplug it.
If its the electrical aspect the problems will go away.

Overhaul if an injector normally means setting the pressure (what you call compressing) and checking the spray pattern. If the nozzle is shot you can usually get just the nozzle replaced.

Trust me that No. 4 is hellishly expensive; mine failed at the top so I had to replace it.

waveydavey said:

Go back to what I said before; unplug it.
If its the electrical aspect the problems will go away.

Click to expand...

I'll check on this tomorrow. Will do the unplugging tonight and see.

waveydavey said:

Overhaul if an injector normally means setting the pressure (what you call compressing) and checking the spray pattern. If the nozzle is shot you can usually get just the nozzle replaced.

Click to expand...

This was done when i gave the vehicle to the dealers to check on this matter. They've given the injectors + the pump to be serviced and checked for the spray pattern. After this was done, my MPG improved as well as the power output was improved.

Now this is major discovery that i made today with my HawkEye. I plugged this in was looking at the live data, specially the injected Qty of fuel. As my father has suspected, the engine was not receiving enough amount of fuel. Normally the qty goes around at 4-8mg/s of fuel and when this jerk/rough idle starts it drops to constant 0.2-0.8 mg/s. This is way too low. And intermittently 10-20 mg/s is seen to be injected.

I will check again with the connector removed from the injector.

Regards,
Gayan.

That sounds very similar to what I had - #4 was false signaling sometimes so the DDE thought there was excess fuel and compensated by shutting right in - result was that without seat belts you would have been face on the windscreen. Once it failed totally the DDE defaulted to its best guess instead of a false measurement and all was fine. I only changed it to get rid of the fault light.

Get in touch with this guy:
http://www.uniteddiesel.co.uk
I was still in the UK when I dealt with him so I don't know if he will post internationally but I really could not fault him. He knew what he was talking about, his price was very good and he even includes the loan of the socket with a window that you need to get No. 4 out.

Hi i tried to get the clip out but i couldn't. Think i'll need to take the turbo manifold out. grrr... don't like to touch uncharted territory. Will try it again today evening and see.

You certainly need to take the manifold off to take the injector out, not sure about the connection though. Try on another that's easier to get at to see how they work and try again.

Mind you the manifold really is a doddle of a job to get off and on again.

You need to be more clear about what is wrong with your engine,the needle lift sensor on #4 injector has nothing to do with the injected quantity - all it does is provide feedback to the ecu about the actual start of injection so it can adjust the pump timing to suit.Basically closed loop timing advance.The injected quantity is controlled by the ecu via the injector pump.if the engine is not mathcing driver demand it will increase or decrease the injected quantity to suit.
Unplugging the #4 lead will only make the ecu run in default using a fixed advance map according to crank sensor signals,driver demand and temps etc.

Hi guys.

Last Sunday, I found that the Nº4, plugged with rovacom, give sometimes 0 rpm, in a road test.

The car runs very slow and more sluggish that he normally runs, but only in hot days, in the night the power is back. :think: (I also a problem with engine temperature sensor 0ºC).

Do really need to change it, or it could be a bad contact?

mmm

I don't think it's the main suspect. It could be of many sensors, Oxygen, MAF, Turbo, so many things.
I would suggest you get hold of a diagnostic tool or a dealer/indie who has one and check your car with it.
If there's some sort of a problem with electrical or sensors it will show you.

If there's something else, some else must pitch in and help you cos this is as far as i can go with the info you have given.

Cheers mate.