Disco 2 Rough idling TD5

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Ok, when my coolant temp reaches 85° fuel temp is 45° (as in the file i shared earlier). Probably should be closer together then, engine was 'hot' when i did these readings.
 
Even that 20* seems a bit high to me while above 30 is unexplainable as the measurement is made on the FPR which is attached to the head and the fuel cooler is on the return... the fuel map was conceived for a medium difference of around 10 degrees, that's confirmed by nanocom guides too, see page 2
 

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I checked 8 logs from different vehicles cos i have many in my database and the biggest difference with hot engine was around 20*C in one case so the 40*C difference is still unexplainable, in most cases the difference is between 10 - 18 degrees with engine at normal operating temp(around 90) though it would have been relevant to know the outside temp when the readings were saved which i dont know

Fist of all on a cold start in the morning after the vehicle stood all night the ECT and FT readings should be very close cos the whole vehicle is at the same temp, then the difference will grow as the engine gets hotter, for example one log from my vehicle which was taken from cold start(not in the morning but after about 2 hours rest) ECT = 32, FT = 27 then after a long run ECT/92, FT/75 but there were moments with ECT/88, FT/79 so i'd conclude corroborated with other reading too that roughly between 10 and 20 is a normal range.... i can't find any logical explanation for a higher than 20 degree difference in a running engine what ever i do.
 
sierrafery said:
I checked 8 logs from different vehicles cos i have many in my database and the biggest difference with hot engine was around 20*C in one case so the 40*C difference is still unexplainable, in most cases the difference is between 10 - 18 degrees with engine at normal operating temp(around 90) though it would have been relevant to know the outside temp when the readings were saved which i dont know

Fist of all on a cold start in the morning after the vehicle stood all night the ECT and FT readings should be very close cos the whole vehicle is at the same temp, then the difference will grow as the engine gets hotter, for example one log from my vehicle which was taken from cold start(not in the morning but after about 2 hours rest) ECT = 32, FT = 27 then after a long run ECT/92, FT/75 but there were moments with ECT/88, FT/79 so i'd conclude corroborated with other reading too that roughly between 10 and 20 is a normal range.... i can't find any logical explanation for a higher than 20 degree difference in a running engine what ever i do.
Click to expand...


Loud and clear ;).

So they both rise pretty consistent, changing the FT today :).

Thx!
 
I have checked some earlier files and seems that during summer time and after longer run (higher air inlet temp) the diff for me also close to 15-10 *C.
But 40 surely high...
Attached two charts. 1st is a recent one done about a month ago, the 2nd one during summer when the engine was already hot.
upload_2020-12-15_16-3-35.png
 
Last edited:
berg450 said:
I have checked some earlier files and seems that during summer time and after longer run (higher air inlet temp) the diff for me also close to 15-10 *C.
But 40 surely high...
Attached two charts. 1st is a recent one done about a month ago, the 2nd one during summer when the engine was already hot.
View attachment 225214
Click to expand...

Hi,

Charts are awesome! Did you make those with the nanocom CSV viewer or something else?

I can't install the nanocom software on my laptop (work laptop and the thing sees it as possible harmfull...)

Thx!
 
Allright!

I changed the fuel temp last night and did a test run.
Original problem is still present :).

Fuel and Coolant temp stay about 30-40° degrees apart, I took a laser thermometer at it and the coolant is pretty accurate but the fuel temp seems higher then the sensor shows (the new one!). Could this point towards an issue within the FPR? I spoke to a local garage shop specialized in landys and he said we might have to look in that direction..

Also noticed that the exhaust manifold is leaking a bit, so a warped manifold is present as well, could this indicate the cause of the original problem? It's not a dramatic warp, i can just start hearing it whistle a bit and see it leaking (form of small tiny bubbles.. :confused:??) at cilinder 5.

I attached the data file (pdf) from the test run with the new sensors.

Thanks guys!!
 

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Laurensvh said:
Hi,

Charts are awesome! Did you make those with the nanocom CSV viewer or something else?

I can't install the nanocom software on my laptop (work laptop and the thing sees it as possible harmfull...)

Thx!
Click to expand...
No, I opened the data in excel and created the charts from there on a simple, easy way.
 
Laurensvh said:
I took a laser thermometer at it and the coolant is pretty accurate but the fuel temp seems higher then the sensor shows (the new one!). Could this point towards an issue within the FPR?
Click to expand...
No, this points toward an ECU misbehaviour, something happened with the ADC within it. At this point you better not invest more money untill you dont try another ECU, though warped manifold can cause the symptom you described
 
sierrafery said:
No, this points toward an ECU misbehaviour, something happened with the ADC within it. At this point you better not invest more money untill you dont try another ECU, though warped manifold can cause the symptom you described
Click to expand...

Hey,

I've tried a different ECU, the primairy problem was still there.. didn't pay attention to the fuel and coolant temps when the new ECU was in tho..

Ok, if the warped manifold my be the cause i'm gonna have that fixed first, has to be done anyway and driving with a warped manifold isnt the best idea :p .

Thx for the info guys, really appreciate it!
 
All these are possible causes which are cheaper and easyer to be ruled out but the main cause of a bad injector balance can be an injector by itself(or more) provided that the timing is 100% well set
 
Ok, gonna start with the manifold and a compression test then.

What are the chances of 4 bad injectors at once and starting at some point instantly? I'm starting to look closer to the warped manifold now (since you say it might also cause the injector unbalance).
I pushed the disco pretty hard on some points this summer, drove it to Italy trough the mountains and pushed him up steep hills to 2600m altitude, drove around the belgian ardennes and did a decent off road trip in the north of France driving hills and rutted out woods all day for 3 days. Since the problem mainly started after I blasted trough a tunnel on the way home from France I think something just gave after all that abuse over 4 weeks.

Hope to have it sorted befor the end of January..
 
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