Member Since: 11 Nov 2022
Location: Chester
Posts: 8
Discovery 4 None Start After Injector Seal Replacement
Hi all,
Long time lurker here but going straight in with a problem for the first post, usually I find the answer im looking for but not today.
Recently I developed a misfire, according to the GAP fuel rail pressure at idle during this was 6,292 PSI rising to circa 12000 when I blip the pedal. Fault code registered "P0302-00 (AF) Cylinder 2 misfire detected" but ran ok if you treated it nicely.
Few days later it starts to cut out as the misfire is worse I can hear some chuffing from the engine bay and now registering "P0087-21 (AC) Fuel rail/system pressure - too low - General signal failure - signal amplitude<minimum" as well.
Take the plastic off and low and behold the bottom right injector (passenger side) was spitting out plumes of combustion gasses and fuel. So I think that looks like a leaking fuel injector.
Removed the injector and the top O ring is brittle and crumbled, and the washer looks like a bit of a bodge job, clearly a washer drilled out to fit as the hole was oblong and you could see drill marks.
Replaced all 3 of them (return pipe, O ring and washer) with genuine seals, after cleaning with seat reamer and wire brush etc and fitted it back in, torqued to 9nm.
Car now cranks with a clunk every few seconds like the starter solenoid is firing or something, but it does not start, there are no fault codes present at all and no obvious signs of leaks.
Highest fuel rail pressure while cranking registered on the GAP tool is 1,123PSI.
Battery at rest was 11.8v dropping to 8.75v at its lowest during cranking.
Charged the battery over night on the car same thing, battery showing same results so ive took it off the car and am charging it now on a better victron energy charger (registers very low / deeply discharged).
My question is what could it be and have I missed anything anywhere in the process, could it well be the battery is a dudd or is it coincidence?
Feedback is most appreciated.
Edit - It was due a service so ive replaced fuel filter, oil filter, oil, air filter and pollen filter as well (britpart filters) if that adds anything. 2014 SDV6
14th Nov 2024 2:04 pm
disco chris
Member Since: 25 Apr 2022
Location: London
Posts: 281
Did you prime the fuel filter before fitting and /or follow the normal fuel bleed procedure? Potentially the fuel filter renewal has meant the engine isn't getting sufficient fuel although I would have thought this was register a fault code...
Are the connectors to the new fuel filter definitely in the correct locations?
I'm not an expert but those are the things I would be checking first, if you're confident your work on the injector itself was sound.
I'd probably also look to renew the battery too as it sounds like yours is on its last legs.
14th Nov 2024 3:12 pm
PAGreen82
Member Since: 11 Nov 2022
Location: Chester
Posts: 8
Thanks for the reply.
Yeah im clutching at straws a bit with the battery by charging it again, will replace it regardless, I guess im trying to rule out low voltage as a reason for possible low fuel pressure.
I'm no time served mechanic or anything but the seals were easy to replace and I put it back in clean to correct torque so cant see there being an issue with that unless im missing something.
I did not fill up the fuel filter before fitting, I just unscrewed it swapped the sensor over at the bottom and screwed it back in tight to be honest. No other hoses or connectors were taken off the housing.
I have attempted to bleed it after refitting the injector via the valve on the top of the engine and switching the ignition on and off, all be it with a bicycle pump adapter.
Fuel did come out but not at any high pressure, more a constant dribble, that may be down to the small gauge hose on the adapter or it be normal for all I know.
14th Nov 2024 3:29 pm
disco chris
Member Since: 25 Apr 2022
Location: London
Posts: 281
The battery voltage sounds very low so I would suggest replacing it as a starting point... from memory it should be about 10.5v while starting so 8.5v sounds insufficient. That could be it...
If that doesn't work I'd be swapping the fuel filter again, maybe with a genuine or OEM part instead of Britpart. Also clutching at straws with that one but I'd be deferring to someone's superior knowledge at this point
14th Nov 2024 4:20 pm
Jimbob42
Member Since: 23 Mar 2022
Location: Leicester
Posts: 183
Could just be fuel filter not primed. Can take a good few ignition on/off cycles to get them to pick up.
14th Nov 2024 5:21 pm
PAGreen82
Member Since: 11 Nov 2022
Location: Chester
Posts: 8
Morning all, well I left it on charge over night, charger was saying it had reached float stage and had a good charge.
Recoded the battery to car and jumped the fuel pump relay for a few mins with the schrader valve open and was running clear.
Crank attempted about 3 maybe 4 times, battery was resting at 12v vault dropping to 8.25v, I can smell a little fuel towards the end of the cranking cycle and battery warning light and steering angle sensor fault is coming up.
Could still be an issue but with priming and bleeding but I guess im not going to know properly until I get a new battery so I have a S5 A13 BOSCH AGM battery from Tayna being dropped off today, a pig that it all happens at once but £180 is not a bad price delivered really.
While im waiting is there any way that the fuel filter could be screwed on incorrectly like not at the right location or the drain valve is located wrong etc, there's no leaks from it and is locked in tight.
15th Nov 2024 10:08 am
PAGreen82
Member Since: 11 Nov 2022
Location: Chester
Posts: 8
Well new battery went on and coded to the car, cranked up a lot stronger.... but didn't fire up.
Just a slight whiff of fuel at the end and what sounds like a starter trying to engage every 3 seconds or so.
Assuming all else above went ok the most common thing that it could be now is the fuel filter priming and air bleeding, ive done quite a bit already but can it really need that much priming and bleeding.
Maybe have to think about retracing my steps I reckon
15th Nov 2024 3:23 pm
PAGreen82
Member Since: 11 Nov 2022
Location: Chester
Posts: 8
Hi again right I took the new Britpart filter as I heard mixed reviews and put on the previous genuine one back on, the water sensor was cracked (must have over torqued it ), ordered a new one and plugged it temporarily.
Primed the filter and bled via the valve on the engine, I loosened off an injector union on both banks to attempt to bleed the high pressure end, definitely cranking stronger.
Eventually it fired up, lumpy but it was going, blipped the accelerator and it died.
Battery is now too low from all the attempts I think as it doesn’t allow the starter to attempt long enough, so it’s back on charge.
What do you reckon give it a good crank again when charged or do some more bleeding on the high pressure end (one bank did have some minute fizzy bubbles still)?
16th Nov 2024 4:50 pm
Jimbob42
Member Since: 23 Mar 2022
Location: Leicester
Posts: 183
Never crack high pressure pipes, no need to. I still say you need to prime the system fully. They can take a fair bit if you’ve ran it dry.
16th Nov 2024 4:53 pm
PAGreen82
Member Since: 11 Nov 2022
Location: Chester
Posts: 8
Cheers I’ll back off on the fuel rail side.
Sounds like I’m underestimating just how long quite some time is, I’ve opened the valve on top of the engine and it runs clear for quite some time but maybe it’s not enough.
What would a ball park would you recommend, leave it open long enough to fill a 5 litre fuel can maybe, or even leave the bleeding and prime without opening maybe?
16th Nov 2024 5:37 pm
Jimbob42
Member Since: 23 Mar 2022
Location: Leicester
Posts: 183
As long as there’s a decent stream of clear fuel that’s enough. I suspect it may just be air if the hp circuit. Just keep cranking with the system sealed. I’d say if the sensor was cracked you have just dragged loads of aerated fuel through, but that will bleed off.
16th Nov 2024 5:44 pm
PAGreen82
Member Since: 11 Nov 2022
Location: Chester
Posts: 8
Right bit of an update.
After a second time flattening my new battery I gave in and called a bloke more knowledgeable than I (The AA), i figured they’ll be able to fire it up or at least check over what I’ve done.
They took the turbo boost pipe off sprayed some quick start in it and after a few mins stalling it started up and ran a treat all be it with an ever so slight roughness.
Big plooms of white smoke bellowing out into the street they said might be a load of fuel from all my cranking that needs clearing, 30 mins later still bellowing smoke and showing signs of run away combustion.
Their diagnosis was that one of the injectors is stuck and that’s why I’m seekmy the smoke and why the rail is hard to get up to pressure.
Most likely the injector is the one I replaced the seals on but it could possibly be another one on cylinder 2 (as I have a code for a misfire on it and he’s not sure the injector I’ve worked on is cylinder 2 and it could be a coincidence) his recommendation take it back out replace with a new one and if the smoke don’t clear swap it to cylinder 2 see if that does it.
Or phone them back up and have it towed to a garage. They said don’t drive it if there’s a risk of runaway combustion
17th Nov 2024 7:11 pm
PAGreen82
Member Since: 11 Nov 2022
Location: Chester
Posts: 8
Hi all, an update.
So new injector is in and it fires up straight away under its own steam stronger than it ever was (thanks to all that helped much appreciated).
I can still see I have a bit of white smoke but thats normal apparently for a while and no way near as bad as the fog it put out prior to changing it, but im having trouble coding the thing.
I have replaced injector 2 on cylinder 4 and when using the GAP tool to update the injector code it produces an error as below when I press update, is this something anyone has seen before and is there a workaround (maybe a software update thing or does the ECU need to be flashed with an update maybe)?
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