Home > Technical > Defender 130 TDCI Puma non starter |
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blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17448 |
I assume no DTCs? What fuel rail pressures are you seeing?
Everything about this screams VCV, I'd try another new one from a reputable supplier. By the way, how on earth do you bench test a VCV? It's a very sensitive flow-regulating valve and cannot be sensibly tested in isolation. |
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1st Dec 2022 3:42pm |
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audi1boy Member Since: 11 Dec 2020 Location: Somerset Posts: 24 |
Will order yet another VCV
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1st Dec 2022 3:48pm |
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blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17448 |
It's rather hard to determine what it is on the ECM that fuse 38 actually does, however the fact that you are not seeing 12 Volts on the fuse when the glow plugs should be on is very suggestive that the GP relay is on the blink.
I imagine that you have checked that you are getting 12V on the input to the relay from Link 1 (there are other things also fed from Link 1 so it is unlikely that the fusible link has failed without you noticing). Provided that you have power on C0215-1 from the link, check also that BJB Fuse 5 is good (this powers the main relay which in turn powers the activation coil on the glow plug relay, with the ECM providing the ground when the glowplugs are required). If the main relay is not functioning correctly you won't get glow plugs, but also I don't think the engine will even crank, so if it cranks (which I assume it does) then the main relay is probably good. Without knowing what the "GPFB" signal on the ECM actually does, it is hard to say if its absence will cause your problems. If you ad access to another vehicle you could pull fuse 38 and see if it then fails to start. You could also try applying power to fuse 38 from an external source to see if the engine than starts, but be mindful of the fact that one of the fuse's terminals is connected to the glow plugs and hence will have a low impedance to ground so a heavy current will flow. The other terminal of the fuse is the one connected to the ECM and I would expect to be a fairly high impedance, this would be the one to apply 12V if you decide to try this. I have a vague recollection that one of the large fuse holders which lies loose on the floor of the driver's seat locker is also connected with the heater plugs and doesn't feature on any of the electrical diagrams. I may be wrong on this, but it might be worth checking that there are no failed fuses under the seat. If you can get hold of one, the next obvious thing to replace is the glow plug relay. *** EDIT *** I see you've edited you previous post whilst I was typing, I am not sure what "end" means! Perhaps you've solved the problem? |
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12th Dec 2022 12:07pm |
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audi1boy Member Since: 11 Dec 2020 Location: Somerset Posts: 24 |
Hi Blackwolf thanks for the help.
So i found the glow-plug fuse had blown which was causing that issue. It was me clumsily earthing the 12v point on the engine. Changed the fuse. Still no start. I have changed the crank sensor, camshaft sensor, fuel rail pressure sensor and the vcv. Im only getting 1.5mpa of rail pressure on cranking. Immobiliser light goes out when you turn the key and arms itself when you lock it.So dont think its the immobiliser. |
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13th Dec 2022 9:48am |
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blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17448 |
Does it crank but not start, or does it not crank?
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13th Dec 2022 11:59am |
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audi1boy Member Since: 11 Dec 2020 Location: Somerset Posts: 24 |
It cranks and turns over but no start.
No fault codes either |
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13th Dec 2022 12:09pm |
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blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17448 |
Unfortunately £engine cranks but won't start" is a very common Defender TDCi problem, as evidenced by the number of threads on the subject, and there are many possible causes including:
camshaft position sensor failure immobiliser issue IPAC issue fuel supply issue including VCV ECM issue Plus probably many others. They also tend to be difficult to diagnose. That being said, the fuel rail pressures you are seeing are very low, I think too low to run the engine (I'd expect around 15MPa at idle), and you have had VCV issues. Did you change the VCV a second time, it isn't clear from your posts above? The purpose of the VCV is to control the pressure in the common rail by adapting the flow of fuel fro the LP stage of the fuel pump to the HP stage, if it is defective it can cause low common rail pressures. Similarly if the ECM, for some reason, is not modulating it correctly, the same thing can happen. Have you checked the fuel system for water, dirt, leaks, and a blocked filter? Water or dirt will kill a VCV is seconds, and if you have had water or dirt then you should change the VCV as a matter of routine. The fuel system on the TDCi is the least-monitored system by the ECM and as such an absence of fault codes tends to point to a fuel problem. |
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13th Dec 2022 12:32pm |
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audi1boy Member Since: 11 Dec 2020 Location: Somerset Posts: 24 |
Hi,
I have disconnected the fuel lines to the filter and the pump etc and blown back through. I have bled it using the Ford suction hand pump and plenty is getting up to fuel pump. I have just ordered a final Denso VCV to 100 percent rule that out. The strange thing on the VCV is there is a recess cut into the VCV for what looks like an o-ring but the o ring supplied is too small to fit into it. Just to double check which order do the seals on the VCV go? I.e working from the front to the back of the vehicle is it o-ring then flange seal? I will double check this. I put the VCV taken off this truck on another Defender and it fired and worked first time. Im now searching for Cummins 6BT to MT82 Conversion plates Last edited by audi1boy on 14th Dec 2022 6:37am. Edited 1 time in total |
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13th Dec 2022 12:39pm |
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blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17448 |
There should be single O-ring fitted to the VCV in the position shown in the photo in the first post in this thread. Between the mounting flange of the VCV and the pump body there is a gasket.
A 6BT would certainly solve any VCV issues! |
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13th Dec 2022 1:12pm |
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audi1boy Member Since: 11 Dec 2020 Location: Somerset Posts: 24 |
Sorry I meant the o-ring and gasket on the mounting face of the diesel pump.
So it looks as though the o-ring and gasket can only go on one way. but if you could confirm this is correct. I know the seal on the snout is missing as this is an old one i had that had a damaged o-ring. Thanks Pictures in gallery |
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13th Dec 2022 4:37pm |
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audi1boy Member Since: 11 Dec 2020 Location: Somerset Posts: 24 |
So I have fitted the Denso VCV and still no luck.
So changed VCV twice Crank Sensor Camshaft Sensor Fuel Rail Pressure Sensor Replaced one injector with an old one out of the engine and it does not spray Checked all fuses Blew fuel lines back through to tank with cap off Bleed fuel supply up to pump. Swapped out relays under seat and checked terminals All fuses ok Cranks but no fire. Maximum of 1.5mpa of rail pressure and injectors not firing. No fault codes other than a failed Pilot learn as it cut out mid process. Id replace the injection pump but I am concerned it is something electronic stopping the fuel supply and causing the low pressure and injectors to not open. Id put another engine in it but again concerned it could be an ecu issue |
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19th Dec 2022 9:06am |
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mwestcrew Member Since: 09 Dec 2019 Location: South Warwickshire Posts: 264 |
Try some EasyStart.
Probably get some howls of disapproval, but it might get the pump spinning fast enough to get some pressure up and allow the VCV to operate. In my experience it certainly won’t do any harm. 2011 130 Utility Body 2005 110 Van |
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19th Dec 2022 9:23am |
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audi1boy Member Since: 11 Dec 2020 Location: Somerset Posts: 24 |
Morning. Yeah Im not afraid of easy start and tried it but nothing. Will just run on the easy start and then die.
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19th Dec 2022 9:24am |
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blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17448 |
Based on what you've done I'd be inclined to think ECM or fuel pump. I've heard of more failed ECMs than pumps.
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19th Dec 2022 10:35am |
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