Guys, what i'm telling here is based on my engineering knowledge and a deep study of the Td5's engine management corroborated with loads of articles i've read on the web and several tests made by myself on my own car, you can keep it simple or aknowledge the complicated theoretical reality which is that even if it runs and
it seems it runs OK such kind of ''hybrid'' can have a shorter life in time but i can't tell why they did it or why they did it this way(maybe it's just about costs), to take it step by step:
1. starting from here:
it started as a question as to why they fitted a 15p instead of another 10p.are they better engines...are the heads less or more likely to crack,etc etc.
the answher for why: from what i've seen there are more used 15P engines on the market than 10P and strangely cheaper , which can be quite normal as 10Ps were used between '99 - early 01' and 15Ps between 01-07(between -04 - '07 on defenders)
about the possibility of crack: IMO yes, especially with the wrong management a 15P engine is more likely to crack cos the working temperature of the injectors is higher as the pressure is higher but there's no difference in the head's material or building technology, the whole management software is conceived to bring an optimal functionality and the addaptive strategy embeds an overheat protection too which on the Eu 3 modells starts with a comparison between the ambient air temp and the coolant temp readings(if you put a Eu3 ECU into a Eu2 car you'll get coolant temp fault code due to the lack of the AAP sensor's temp reading on the Eu2 modell)... so i'm saying that 15P engine with Eu2 ECU/map is exposed to the risk of overheating not even a visible one cos the gauge leaves the middle at around 115*C which means the engine can run between 100 and 110 without you even notice it and that in time will ''tenderise" the head cos only at 110C the electric fan kicks in to help cooling(and non-aircon modells dont even have it)
i like to keep the nanocom on instrument mode-first page to see the coolant temp(dont ask me why

) when i make longer trips when it's warm outside and in the hottest days the coolant temp on mine(10P) is 91*C... check yours too in a warm day and maybe you'll realise that it's hotter than that...IMO anything above 95-100 becomes risky
on a long run especially if the cooling system is not PERFECT...and there are many things involved inn that too
there is a timing issue too due to the different injectors as the green top injectors are different and the timing is part of the map loaded in EEPROM and differs from Eu2 to Eu3 (read the attachment and maybe you'll understand)...that's why the balance might not be the best too
it would be interesting to make a statistic of how many cracked heads or failing injector seals are from bad managed 15P engines and how many from 10P engines
2.
The possibility of a replacement (ie 2nd hand) engine harness having problems is quite high and costly, plus the ECU and AAP - you might be talking £500 plus and for what?
If she runs OK leave well alone I say. There will almost certainly something that comes along that WILL need fixing, so hold back that 'spare' £500 I say.
i've never said to use second hand harness only second hand ECU, and if somebody can afford i say it's better to make things 100% right...and it seems that @
cambridgecockney can afford as for the price of a new ECU(£529.99) which he seemed to be up to get it he can buy a new engine harness + a second hand ECU + a 4pin AAP sensor which strangely is much cheaper than the old 3 pin one
based on what i said about injectors and ECUs and fuel maps i hope you can agree that it could be a difference between the feeling that it "runs OK" and the fact that it runs perfect and riskless

... what i explained above it's just the top of the iceberg believe me but i dont have the mood to write the whole theory here
3.
Ok cheers.
a)is there a number ecu you recommend as i noticed there are several different nnn ecu types for manual.
b) also if i can find newer engine loom where do i put 4th wire.
c) where do i find Eu3 nanocom map wizard.
a) there are only 3 NNN ECUs compatible with manual D2:
NNN000120, 500020 and 500250, there are slight issues with the first two as they were used on defenders too and there's a not perfecly engineered thing with the clutch switch input which is the other way around on defenders albeit i saw several well working on D2s...anyway IMO better than a Eu2 one... the 500250 is exclusively D2 dedicated and forget what i said about the maps cos it's not the case here as the problem is to be remapped for 10P engine which it can't accept just the other two can...so if you can source a second hand
NNN500250 that would be my choice.... wait for the opportunity you dont have to hurry just make sure you have a perfectly working cooling system and the additional colling/aircon fan is in working order ... to sustain my theory there are more threads but one of the most relevants is here
NNN ECU PROBLEM - Page 2 - Australian Land Rover Owners
b) the newer engine loom has the 4't wire and the plug for the 4 pin AAP sensor included that's why you need it... but if you get hold of a 4 pin plug from a braker and you will go for that mod i'll tell you how and where to connect the 4'th wire
c) unfortunately i couldnt make tests on my own as it's 10P but there is a map wizzard in nanocom evo's menu which can be used(info attached)...for how to use that you have to ask somebody in the nanocom forum if you want or even here maybe you find somebody to guide you better than me cos i know it only in theory
i rest my case now cos it may become boring i just wanted to explain why i said what i said to show that i'm not just speaking in vain and i dont have a fetish on making people to misspend money
if you have any questions feel free to ask but i'm not gonna start a debate on what i said cos i know it's right and i dont need to demonstrate it... i mean well and that's a fact
