Help! Td5 90 2000 Miss Fire on Cylinder 1. I have looked through existing threads but I am drawing a blank!!

1) Showing no faults on Nanocom.
2) Each Injector fires when in 'Test mode' on Nanocom.
3) Lumpy and slightly erratic Idle, Cylinder 1 imbalance reading at idle,
4) Exhaust port stone cold on Cylinder 1 after running for a while.
5) Plumes of smoke (White but not water) when power demanded.
6) No Fuel in sump.
7) No water loss or back pressure in coolant reservoir.
8) Replaced injector loom inside rocker cover as a precaution
9) Replaced fuel filter, primed and ran with same issue.
10) Was running perfect beforehand, have googled symptons and so far i have got....
11) No oil in loom, red plug or ECU.
12) Injector coding is correct.

A) Faulty injector seals - Discounted due to no blow back into tank or sump.
B) Warped head / Blown head gasket - Discounted due to no oil loss / coolant loss or pressure build up in coolant reservoir.
C) Fuel pump / Pressure regulator defective - discounted due to cylinders 2 through to 4 are within parameters.

Am I missing something here??

Hi @T0P5Y

May seem silly, but have you thought about changing injector 1 over with one of the other injectors to see if the fault moves over as well? I assume if you change the injector codes then it should not be an issue trying this.

Cheers

neilly said:

Hi @T0P5Y

May seem silly, but have you thought about changing injector 1 over with one of the other injectors to see if the fault moves over as well? I assume if you change the injector codes then it should not be an issue trying this.

Cheers

Click to expand...

Hello Neilly,
Thank you for your reply, I am starting to sway towards a mechanical failure of the injector, maybe it is stuck or blocked etc. I am probably going to go down the route you suggest and you suggestion backs up my probable next move. I was wondering if I was missing something simple first before I start getting invasive, not used to changing Small injectors with fine tolerances though, Last week I changed 24 injectors on a V24 and they were each the size of an upright hoover!!

Thank you.

Hi @T0P5Y

If you have not seen it already, have a look here. There is a good write up on the injector removal.
http://www.discovery2.co.uk/Injector Seals.html

The other option is not to bother refitting and either try another TD5 injector in there if you can get one to use / borrow. Or just send it away for testing. Again for a true test you would need to recode, but as I understand it , an incorrectly coded injector will run , but may be rough.

Cheers

I took top cover off and reset clearances as 1/2 turn back from bottoming out
worked wonders for the misfire

Don't forget things other than fuel can cause a cylinder not to fire, low compression due to a stuck or burnt valve, insufficient air getting in. Once had this with another non LR engine and it was because the cam lobe for a inlet valve had worn that much it didn't have enough lift (hardening had gone), the hydraulic lifter had taken up a lot of the valve extra clearance but it just couldn't breathe enough. A simple compression check would check the valves, the cam is a bit more complex to measure but if you watch the valves if one isn't moving as far as the rest then that may be an indication

Also I note that that you said you had white smoke in the exhaust, that is s sign of unburnt fuel so that would seem to say that your injector is working, either that, or stuck open.

My 300Tdi had similar sounding symptoms, but after a minute of feeling a bit rough it seemed to sort itself out. Turned out injector wasn't working properly, was running lean, therefore hot and it melted the top of the piston. Sounds like you know what you are doing so will be more cautious than I was, but thought I'd mention it. Let us know the solution when you get there.