Thanks. Going to plug back in...
Datatek
Well-Known Member
But it still doesn't go so you have missed something. Needs proper diagnostics IMO.
Graculus
Well-Known Member
Have you looked at what P0088-nn actually means? it's overpressure.
The LTB references P0088-17 specifically, which your generic code reader won't be able to pick up, and certainly won't be capable of the reset routine - if it's just a generic code reader.
The measurements certainly do exist, some have to be done manually with a voltmeter, some have to to be read as live values from the Engine Control Module.
I fail to see how a genuine HPFP you claim to have fitted is 'saving time & money' given the three-figure cost of just that item, the fuel pressure sensor is only available with the fuel rail, again, a significant cost.
Which manual are you referring to? the owners manual? The HP fuel pump lockout is cleared automatically when using the manufacturers diagnostics other systems, such as Autologic etc. have it as a separate routine.
I've given you the information - and asked for information back to progress the diagnostic path, which has seemed similar to how I'd imagine banging my head on a brick wall would be, so put your '40+ years with an absolute hate off all modern electrics etc.' to one side, go back to basics and have a read of the LTB I've provided.
I'll let someone else take over from here, Ive lost interest frankly.
Advanced factors list and sell the sensor separately. Thanks for your help so far.
Yep. That is on the list to look at too. As advised we are going to take the plunge and get a GAP IID tool. Have refrained before as often change our vehicles, and so our generic tool for all vehicles has always sufficed. However if can fix this issue may keep RR as its alright! Apart from not going!!! Also going to do the modification to the pressure sensor wiring harness. Won't cost us and rules it out.
Absolutely! I have missed something, and scratching my head as to what. Proper diagnostics will def help, and so going to invest in a GAP IID tool. My generic one is great, and very useful for giving an idea. TBH I change cars quite regularly and so never invested in a specific one. Our Merc ones and JD ones at work are fantastic. Have a step by step guide to what you are doing and everything. They are manufacturer supplied only. Quite like this RR, and this is the first major issue in 3 years. If can sort this will probably keep for a while yet. Missus likes it for towing her horses too. While waiting for tool to arrive will do the mod of the pressure sensor wiring harness, as that won't cost me and at least can rule out. Wondering on the CKP too, but going to wait for tool...
Camshaft sensors don’t tend to throw a code unless they are FUBAR.
If their signal line is just ‘off’ on volts, it won’t start.
You can back-probe them to test.
Still no joy. We have gone through everything from the very beginning. Full tank of fuel. Gauge reading correctly. New fuel filter. Genuine. New sensors. New Bosch HPFP. Fitted and timed correctly. LTB01083 modification done. New CKP. Fuel rail sensors replaced.
Some live readings... Fuel rail pressure sensor 91psi ignition on. Crank no change.
FR pressure sensor 0.3v
FR temp sensor 2.1v
Fuel volume control valve 15.3%
There is no fuel getting to the rail. No fault codes coming up anymore. At our wits end! Any other suggestions?
Some live readings... Fuel rail pressure sensor 91psi ignition on. Crank no change.
FR pressure sensor 0.3v
FR temp sensor 2.1v
Fuel volume control valve 15.3%
There is no fuel getting to the rail. No fault codes coming up anymore. At our wits end! Any other suggestions?
Please can you tell me more on that? We cant find where it would be or an option for it. GAP iid tool... Thanks
Not that we can find... looked in all the usual places and cant find one or find info on there actually being one...
What I meant was we cant find it as an option on our diagnostic tool. Or in which menu to look under. Hopefully someone can shed some light on that.
Ok. So this making my head hurt trying to work out what is happening here! And following pipes... Again... right back to the beginning but remembered something that I thought was really unusual, but put it out my mind. Why I don't know. I noticed fuel coming out of the return line from the HPFP. And today when going back over everything, took the return line off at the secondary pump, where fuel was coming out, under pressure, from the return line. So basically the fuel flow is being reversed! Return line from the tank is blowing fuel out. Only thing I can think now is the in tank pump has gone wrong...
Pipes on the wrong way somewhere? 
Graculus
Well-Known Member
https://www.landyzone.co.uk/land-rover/cranks-but-not-starting-2012-4-4-tdv8.396187/#post-5782280
It may also be simply fuel returning from the injector spill line which connects to the return, the non-return valve will require some pressure to actuate, removing the return line from the HPFP will cause that pressure to vent from the line there.
Have you tried blanking off the injectors at the fuel rails one at a time to see if one injector is excessively passing? there is a minimum requirement of 10 bar at cranking for the injectors to atomise sufficiently. I've seen a lot of Audi 3.0l V6 diesels brought to a halt by a defective fuel injector passing back to tank excessively, not many 4.4TDV8's though.
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Dont think so. We did check, but they are all different sizes and so can really go on in one way. Besides, nothing had been touched before it cut out, so doesn't explain why it suddenly cut outPipes on the wrong way somewhere?
Haven't blanked off injectors yet, but that could def be something to try. Does seem unlikely though as fuel isn't getting there. Next week when off of nights... Did think about the non return valve too, and if that is open would allow fuel through... Spoke to LR today who are equally perplexed. They said we have done everything they would and they wont take it in to look at! Suggested a diesel specialist such as PB Asher.
