Rough idle, sudden misfire during cruising and hesitation

I took the measure as dead end at the end of the line going to fuel cooler, with this Which means it will likely give the full preassure right, therefor 8bar i guess.

I think i have the fuel lines correct as u described here is an image.

make sure that the circuit is completed as in the pic at the filter so the return from the cooler to not be instead of the LP return or the air bleed connection at the LP feed

yes on the 8 bar no T peice just saying

your true rail preassure is read from the outlet at the head with a T peice and not at the fuel temp sensor location either

anyways to low of a fuel pressure you would also experiance some sort of diesel knock ?

Well there is a sort of knock to it in combination with misfire. I am now in midst of replacing the injector seals once more just in case.

Ok, so what I didi today was replacing the injector seals, cleaned up the loom. The ECU was completely dry so nothing have gone there. I pressure tested also the head and fuel system for airleaks and it seems solid. There was slightly more power and the though the idle is still slightly rough and having a slight sound of.... misfire/detonation... or how I would describe the slight sporadic crackle, its less than before. I recorded my ride back from the garage and here is the PDF with last readings. Do they differ from the previous one in your eyes? cheers, niklas

northernbobber said:

Do they differ from the previous one in your eyes? cheers, niklas

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Not much, powerwise it's the same and there is no idle recording only a little at the beginning... what about the clutch and brake switch inputs? if these are not OK the ECU reduces fuelling .... and the fuel lines at the filter are in the good order?

damn, i forgot to check those switches. I check them tomorrow. Yeah I went thru the fuel lines to check they are set correct as you recommended. I replaced the filter housing and filter last week and all lines are coming off and going back on as they should and no leaking. I think they are ok. I get back to you tomorrow when tested clutch and brake switch inputs.

I tried the switches. Both went from OFF to ON when I depressed respective pedal. So seem to work. Then I flashed the ecu with an older map which brought it back to the super lumpy bad running it was before I remapped it. So I think that was the map that was in it then, so I flashed it back to the latest Def-110 EUROPE map and I am back where I was.

The thing is. The previous owner said they were called back for a remapping after they had bought the car as new. Nanocom MapWizard gives 3 maps for EUROPE Def-110 MANUAL. one in 2001 and two in 2002. The first in 2002 seem to be the bad map I have experienced as I now have the newest 2002 map in and it works way better. You think I should try the 2001 map? (I think that was the one they were called back from to be remapped in the first place, but I don't know if they experienced any issues wuth the original map or why there was a call back).

Is there any proven good map I could try. Does it have to be EUROPE market map or could I try an american or some other map for def-110 or could even a def-90 map work?

The remapping has made the biggest single improvement for me so far for this car (besides replacing broken parts as injectors and fuel pumps etc.) so I am kind of keen to see if that could be the root for the problem.

are the injectors with green top?.... did you try with MAF unplugged?

Yes I have the greentops. I have not tried running with MAF unplugged, I had some success unplugging the ambient air preassure sensor with the previous map (the really bad one). It calmed down the lumpiness a little but with the new map no difference really. I will now go out and record a ride with MAF unplugged...

Here is the run with MAF unplugged. Do you recon I dare to try flashing the ecu with the 2001 TD5 def-110 europe manual map?

For green top injectors any TD5 Defender EU3 fuel map is good... the problem i see in your data logs is that the air flow -boost relation is too low under heavy throttle(MAF doesnt even reach 300 and the max boost i've seen was around 0.8 bar) and the air flow reading is low at idle which can be cos the idle is a bit lower than normal too.... the whole thing looks like that engine doesnt get enough fuel into the combustion chambers which can be an injection management issue as the fuel delivery system was quite ruled out except the FPR.... that 8 bar on the return is quite suspect, undo the return pipe at the filter and if there is a valve in it simply remove it and make a drive test without it cos if it restricts bad the return it creates back presure in the FPR so less fuel into the rail ... on early modells that valve was not fitted at all.

on a well fuelled stock map Defender Td5 engine, under heavy throttle you should get MAF around 600 and boost 1.2 bar(MAP around 220) while your's is just a bit over half of that

I have the valves inserted in the filter. My previous housing was without (if you mean the red/orange valve) which caused starting issues below 1/4 of a tank. Or do you mean the white small valve?

NOT the white one cos that's important, BTW what's the fuel tune ID and config ID of the map you have now ?

Where do i find the ID info?

northernbobber said:

I took the measure as dead end at the end of the line going to fuel cooler, with this View attachment 177022Which means it will likely give the full preassure right, therefor 8bar i guess.

I think i have the fuel lines correct as u described here is an image.
View attachment 177024

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you should measure fuel pressure at the switch or using a t piece so you can see you get 4 bar under running conditions

northernbobber said:

ive done some major rebuilding and had the Def 2002 running pretty sweet for a while though the slightly rough idle remained. Suddenly today i started feeling severe hesitation at cruising speed on all gears. Still pulls strong and no hesitation when under heavy load. But slight load and cruising start to jerk and misfire. I have replaced injectors, head gasket, everything in fuel line way including filter housing which solved bad start at low tank. Injector loom etc all replaced. I was thinking about giving the injector seals one more go and see where it takes me but otherwise clueless. The idle has funny sporadic raspy sound to it coming and going, could be the misfireing. Any clues, could something else but injection cause this?

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what were replacement injectors,new,recon,tested or a unkown used set

northernbobber said:

Where do i find the ID info?

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You should be able to read it with nanocom, didnt you read the user guide?

sierrafery said:

You should be able to read it with nanocom, didnt you read the user guide?

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This is the map i have now svloe005-svtnp005.

jamesmartin said:

what were replacement injectors,new,recon,tested or a unkown used set

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Well, you might be on to something, this was my last resort if all else fails. Since they are reconditioned DELPHI injectors. When I received them 2 was out of specs and engine would just bog and not pick up revs at all. I spotted the faulty ones with nanocom's compensation values and they were replaced. Then it has been running sweet except for the rough idle and and occational feeling of misfire. SO I am suspecting there could be some other injector out of specs too... We did a test running black tops before I ordered the injectors to be sure it was an injector fault. We used the p10 injector rocker shaft with the black tops and it was rather smooth from what i can remember.