longshanks Posted August 24, 2017 Share Posted August 24, 2017 Hello all. Wondered if anyone can shed any light on an issue I seem to have with my Disco td5. I bought a Td5 disc a while back. It was a spares or repairs but was running and being used by the previous owner until the mot ran out. The guy I bougjtbit from said it was running but wasn't running right. He had changed the injector loom as there was oil in but had not cleaned the ecu plug out. So I put the problem down to this, not knowing much about the td5. I have now done all the jobs needed for mot and have started to focus on getting it running right. The problem seems to be there's what feels like a slight miss around 1700 rpm. It starts on the button and ticks over fine . I have cleaned out the ecu plugs , fitted a de-egr plate . Cleaned the map sensor replaced the mass air flow sensor as the other one was faulty. Changed the injector washers and o rings. I have plugged in my hawkeye and it shows no faults . Checked the live data and everything seems ok apart from the cylinder roughness which fluctuates quite a bit at the point where the miss starts approx 1700rpm. It blows no smoke at all even when the misfire starts. I have also checked the injector codes and they are all correct and in the same position as the hawkeye says. Does anyone else have any suggestions on what I could next. (Apart from hit it with something heavy or set fire to it !) Any advice would be greatly appreciated. Thanks Neil Quote Link to comment Share on other sites More sharing options...
sierrafery Posted August 25, 2017 Share Posted August 25, 2017 Hi, did you adjusted well the injector clearances after you changed the washers? Quote Link to comment Share on other sites More sharing options...
Snagger Posted August 26, 2017 Share Posted August 26, 2017 I'd start by putting a can of injector cleaner in with half a tank of fuel to keep the concentration up, and when near empty, use a good quality fuel and see if it starts to clear up (I like BP Ultimate). My RR (Tdi) started playing up with a small surge and stutter at about 1800rpm after I tried a weak mixture of brand new vegoil in the diesel (about 20% blend), and cleaning the system through helped considerably (the pump eventually had to be rebuilt, which was what finally fully restored normal operation. So, bad fuel is a very plausible candidate. Quote Link to comment Share on other sites More sharing options...
longshanks Posted September 15, 2017 Author Share Posted September 15, 2017 Sorry for the late reply sierrafery. Yes they were adjusted correctly . My mate has some auto data software on his laptop and were adjusted to the specified tolerances. I will try some injector cleaner aswell see how it goes. Quote Link to comment Share on other sites More sharing options...
sierrafery Posted September 16, 2017 Share Posted September 16, 2017 Autodata is not accurate when it comes to the Td5, it's full of mistakes(i compared it with RAVE that's how i know), on most of the other PD/EUI engine the clearance is half turn back from bottom but for the Td5 is full turn, ask the mechanic if he remembers how he did it, if no fault codes logged and the injector roughness is not the best the most suspect is the fuel pressure, remove the fuel pump and clean the mesh filter from it's bottom cos if the washers were leaking that will be full of crud, eventually check the strainer under the FPR or measure the fuel pressure with a gauge inserted instead of the FT sensor in the FPR Quote Link to comment Share on other sites More sharing options...
longshanks Posted April 26, 2018 Author Share Posted April 26, 2018 It' been a while but eventually got round to doing a bit more investigating on the disco. I tested the fuel pressure as suggested and got a reading of 4 bar but I thought I would swap over the pump just to rule it out. I took out the fuel pump and got hold of another second had pump (vdo). At the same time I replaced the filter head and changed the valves inside too. Purged the fuel system she started with no problem, So took it for a spin. The replacement pump however was very noisy so wasn't sure how long it would last. The misfire however seemed to disappear! Great so i thought . About 5 mins later she started spluttering then cut out and refused to start . Managed to tow it home and set about re-fitting the original pump back in. She now refuses to start. I have no fuel pressure at all , I have removed the feed pipe to the fuel press reg and bugger all is coming out ! Tried the purge cycle and no amount of purging produces any fuel to the engine ! I have a quarter of a tank of diesel in which I would have thought was enough to get her going. I have also tried a new pump , checked and swapped relays, fuses,power supply etc. Please help before I torch this car ! Quote Link to comment Share on other sites More sharing options...
sierrafery Posted April 28, 2018 Share Posted April 28, 2018 First of all can you hear the pump running? Quote Link to comment Share on other sites More sharing options...
longshanks Posted April 29, 2018 Author Share Posted April 29, 2018 Sorry for not getting back sooner sierrafery . I think it' sorted. To answer your question yes the pump was running . I had flow from the low pressure side of the pump,but no low pressure return. I am presuming that's why I had no feed coming from the high pressure side as I presume the low pressure side of the pump feeds the high pressure side. I got underneath and traced all the fuel lines to check they were going to the filter head in the correct positions. Turns out the return from the fuel cooler and the low pressure return were on the wrong sees of the filter. The car has always run like a pig since I owned it. Now I know why! Swapped pipes over and eventually with the help of jump leads and my van we got it running ( after lots of cranking and purging . ) we removed the air bleed valve during swapping pipes over just to see if it made any difference. I have now re-fitted a new one as there was lots of air in the fuel lines again after leaving it overnight and was a pig to start. She started no problem this morning so here' hoping it' sorted now. Haven't road tested yet but the miss-fire has gone now . I will be testing it today so will let you know how it goes later. Thanks for your replies. Cheers Neil Quote Link to comment Share on other sites More sharing options...
longshanks Posted May 2, 2018 Author Share Posted May 2, 2018 Finally road tested the car and it' running the best it has ever done. It appears it was probably pipes to the fuel filter housing fitted the wrong way round. Thanks for the replies. Cheers Neil 1 Quote Link to comment Share on other sites More sharing options...
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