Member Since: 17 Sep 2013
Location: doncaster
Posts: 53
discovery 3 injector fault
As most know i bought a d3 2.7 with a brokern cam after having heads repaired and refitting everything .the vechical started up great then after a few seconds it dropped onto 5 clyinders and smells very diesaly .bluey smoke from rear .soon as i unplug number 2 injector smoke clears .but before i go buy another
Dose anyone know the correct rail pressure st idiol..injector pressure of injector.
And clyinder compression .
As im hoping its a injector and not a bloody valve ....any help be greatfull.oh ps do these siemans injectors need coding when replaced
7th Oct 2013 4:34 pm
will247
Member Since: 05 Jan 2013
Location: York
Posts: 709
Check out my on going thread, shows the figures on page 2
http://www.disco3.co.uk/forum/topic101568.html26 and on the 4th LR..
Series 2a 1963 88'' 2.25 Derv as original with Galv chassis
Disco 1 1996 V8 on LPG (sold now)
Disco 3 2005 TDV6 S (sold now)
Disco 4 MY15 XS Commercial
7th Oct 2013 4:49 pm
powernut
Member Since: 17 Sep 2013
Location: doncaster
Posts: 53
Cheers nice read there .but mines a bit differnert ill try explain to all bare with me on this
After having heads checked and headgaskets fitted along with other parts .all built up and fuel injectors were refitted in the correct order .
Engine starts first turn of key .but running on 5 clyinders with (eye stinging blue smoke ) .i assume unburnt diesal
I plugged my autocom fault reader in .and every injector shows in the region of 650 but number 2 clyinder shows 1300 .soon as i upluged the injector smoke instainly clears ..so assumed a faulty injector .so i thought if i swop 2 injectors around just to see if pressure offset balance would change .
It dosent for some reason still shows the same value of 1300.
I then checked the compression and the same 2 clyinders .
I was hoping might have been a valve issuise ..
Any idea why this onr clyinder shows a high value ..evern when injector is swoped for one reading 650
As the battery has been off for a while .is it possible a ecu issuise to cause this
Odd thing starts boost and miss clears soon as engine rpm is lifted just aboue idiol but the blue smoke dosent .until i unplug the no2 injector and smoke clears... i can add some graphs if anyone can advise as i dont think its a injector fault
7th Oct 2013 9:02 pm
tomtom86
Member Since: 09 Mar 2013
Location: Here and there
Posts: 590
What about if you ignore the offsets and unplug the injector when it's in another cylinder, does it still stop the smoke or I s the smoke coming from cylinder 2 no matter which injector is in there?
7th Oct 2013 9:20 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
I may have misinterpreted your first post but do not disconnect the wiring to an injector when the engine is running. If the injector happens to be open it will do serious damage to your engine.Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 17 Sep 2013
Location: doncaster
Posts: 53
Cheers robbie good point .yet when a injector is unpluged how dose itstick open with no voltage to it.
Regards injector soon as no2 is unplugged smoke clears only on that clyinder.
When 2 injectors were swopped around ( from a lower reading 650) still smokes and shows the same reading of 1300 on that same clyinder ( hope this sounds a little clearer)..(no2 constantly shows the missing and blue smoke )
May just remove rocker cover and camshafts and relif the hydrolic lifters or renew them incase one is sticking .( yet as compression shows fine on both .im not 100percent its this .
7th Oct 2013 9:42 pm
tomtom86
Member Since: 09 Mar 2013
Location: Here and there
Posts: 590
I wouldn't have thought it would show an injector imbalance due to a lifter sticking as the Ecu wouldn't pick that up. Has it got any stored fault codes? You checked the voltage readings to each injector plug and that the wires/terminals are ok?
7th Oct 2013 9:50 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
powernut wrote:
Cheers robbie good point .yet when a injector is unpluged how dose itstick open with no voltage to it.
It may have no voltage but if open when power is removed it still has hydraulic force acting on the tip of the nozzle and this is greater than the force acting on the control piston in the control chamber. They may be piezo activated but the force produced by the piezo is very small and the hydraulic balance does the real work and piezo is more akin to a trigger.
From the manual:
Quote:
NOTE :
Each Injection event is controlled by a charge and discharge cycle allowing energy to dissipate in, and recover from, the injector. Never disconnect the wiring connector when the vehicle is running. The injector may remain open thus causing engine damage.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 17 Sep 2013
Location: doncaster
Posts: 53
Nice one robbie ....i know now its not the best way .but its found were the fault lies .also this gives me an idea checking voltage from each plug ..
7th Oct 2013 10:11 pm
tommohawk69
Member Since: 20 Aug 2013
Location: Tamworth
Posts: 25
It looks like you have identified the cylinder that is at fault and I would agree that the injector is not the root cause here. In order to verify this you can check the individual spill return from each injector and compare across each of the six cylinders, but do them all at the same time.
Even if the injector is compensating to the max the return flow will be consistent with the others if the injector is in good order and the fault is within the cylinder. If the injector had electrical issues less fuel will spill and hydraulic issues mean more fuel will spill to return.
Has the oil level been checked and is there a diesel smell to the oil? Do you have a constant chuff from the exhaust or is there popping at the tailpipe? If you run without the air inlet is there any popping into the plenum chamber?
Having disconnected the injector and stopped fuel being delivered to the weak cylinder the smoking stops, meaning that the deficiency is related to the cylinder causing incomplete burning of the fuel being delivered.
A compression test and a cylinder leak test would be the next step for me but don't disconnect piezo type injectors with the engine running, I'd say you've been lucky so far. If you have access to a tool that will do an electronic cylinder balance / compression test even better.
Good Luck!
7th Oct 2013 11:39 pm
powernut
Member Since: 17 Sep 2013
Location: doncaster
Posts: 53
Hi tom as said above compression are dame on both clyinders .
No smell of diesal in the oil
And oil hasnt raised on the dipstick
Soon as injector is unpluged from this clyinder .blue smoke instantly clears
Hernce as it showed 1300
I swopped 2 injectors around from another clyinder that showed 650
I will order a spill kit and try this next
Autocom dose give injector balance of each injector on idiol.
Also forgot to meantion no2 clyinder is wet with unburnt diesal.
I contacted the formor owner .he stated everything ran well until the cam snapped on the other bank
So im going to recheck the hydrolic tappits and camlobs .as i phoned the company who checked valves all were removedchecked clean and reseated along with all the lifters and tappits relived from old oil .
Odd thing i do remember when i fist fired it was on 6 clyinders as the tappits bleed up with oil the mis got worse and started blue smoking .??
Yet shows near idenical compression on both clyinders .
8th Oct 2013 8:17 am
hugeviking
Member Since: 08 Jun 2010
Location: cotswolds
Posts: 1482
Worn/damaged valve guides ??
Andi
8th Oct 2013 7:46 pm
powernut
Member Since: 17 Sep 2013
Location: doncaster
Posts: 53
Hi pal these were apparnaly all checked and replaced when both heads were stripped repaired .( i did ring them bk up eailer today .just to double check.
So today as the spill kit hasnt arrived yet i decided to remove both camshaft and just have these double checked along with 4 new hydrolic lifters just incase it may have been a sticky lifters .
I should have meantion that when i was first started with it rebuilt it ran perfect on 6 clyinders until it was turned off to refit fan plastics .as it was restarted it had a slight miss .to a full clyinder missing .
Ps has anyone ever known the camshaft pulley on the osf bank (one with rubber bush in it to possibly move )
8th Oct 2013 8:29 pm
ChappersDisco
Member Since: 04 Aug 2015
Location: Northants
Posts: 1
What was the fix for this? I know it's along time ago but I'm having the exact same issue now...
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
