TD5 disco 2 maf and ambient air temp sensor

Dieseldog57 · Nov 11, 2020

Absolutely no power, couldn’t get up hills in second, diagnostics were reading wrong I.e map sensor showing 119.9c temp and very little range of pressure. Maf sensor showing zero. Now all reading correctly and sounds awesome (straight through exhaust and no cat)

berg450 · Nov 15, 2020

sierrafery said:
AAP(ambient pressure) = real ambient pressure on barometer in kPa, around 100 must drop up to 2 units to 3000+rpm, more decreasing of that value related to the acceleration should indicate that the air beyond the filter is less than required

Today I have run a diagnostic using my nanocom just to see if all parameters are correct. I have found AAP around 96 under heavy load (96.3 at 604 MAF, 3500rpm, turbo 215Kpa). Does it mean something is wrong, or it is still within limit?

sierrafery · Nov 16, 2020

berg450 said:
Today I have run a diagnostic using my nanocom just to see if all parameters are correct. I have found AAP around 96 under heavy load (96.3 at 604 MAF, 3500rpm, turbo 215Kpa). Does it mean something is wrong, or it is still within limit?

215 - 96.3 = 118.7kPa(below 1.2 Bar) boost which for a facelift is a bit low. At 605 kg/h sucction you should get close to 1.35 bar. In what shape are the intercooler hoses ?, aren't they soft ? also check how many threads are between the wastegate rod and valve(should be around 13 from factory), the diaphragm and spring in the valve and turbo hoses are getting ''tired" in time so tighten the locknut to 11 threads and see then, if it feels better then IMO it's time for a new valve and eventually new silicone hoses. Do you still have EGR ? If yes that can be another issue so check if the valve and the MAP sensor are not gunked up.

berg450 · Nov 16, 2020

sierrafery said:
215 - 96.3 = 118.7kPa(below 1.2 Bar) boost which for a facelift is a bit low. At 605 kg/h sucction you should get close to 1.35 bar. In what shape are the intercooler hoses ?, aren't they soft ? also check how many threads are between the wastegate rod and valve(should be around 13 from factory), the diaphragm and spring in the valve and turbo hoses are getting ''tired" in time so tighten the locknut to 11 threads and see then, if it feels better then IMO it's time for a new valve and eventually new silicone hoses. Do you still have EGR ? If yes that can be another issue so check if the valve and the MAP sensor are not gunked up.

I already have silicone hoses but the original ones also showed same values. Egr removed, Map new one, decat pipe. Wastegate rod is already on 12 thread.
A year ago i have checked the system for leak, measured turbo pressure at inlet manifold, seemed to be ok.
I suspect turbo as it was renewed by previous owner by using a new cartridge (not the best quality according to a turbo specialist who checked it about 2 years ago).
The car runs fine, the only thing i still miss is the power on low rpm.....

sierrafery · Nov 16, 2020

Then you should think about a remap for that, i would try https://stormtuning.com/ , from all i've read on forums they develloped a kind of "hybrid" fuel map for Eu3 engines where the MAF sensor is completely neglected but the car runs beautyfull based on reviews(off course i can't explain more as it's not public info which is understandeable even though i dont undestand how it's possible) i trust them so one less thing to worry

berg450 · Nov 16, 2020

sierrafery said:
Then you should think about a remap for that, i would try https://stormtuning.com/ , from all i've read on forums they develloped a kind of "hybrid" fuel map for Eu3 engines where the MAF sensor is completely neglected but the car runs beautyfull based on reviews(off course i can't explain more as it's not public info which is understandeable even though i dont undestand how it's possible) i trust them so one less thing to worry

I forgot to mention that the car has remapped by the previous owner (i have no details about it) and the MAF is less than a year old and genuine.

sierrafery · Nov 16, 2020

I understand that but as long as you dont know exactly what kind of remap was made it's a lottery... it can be(i'm alost suret that is) a generic injector duration remap which is ''old school'' and not the best. They are making AFR remaps these days, if you have a base of knowledge for these things you'll understand the difference from here https://discotd5.com/td5-tuning/injector-duration-maps

berg450 · Nov 16, 2020

regarding on remap. I was also thinking about it in the past (as I do not know what kind of map I have) but it is not so easy from hungary. Even I have Nanocom, I do not want to risk having a bad (interrupted) software upload and having a dead ECU. My nanocom is not so "stable" many times frozen and if it happens during mapping then I am in deep s...t (as far as I know

).

sierrafery · Nov 16, 2020

There were some "glitches" with that when the ''operators'' didnt back up the battery with a charger then... i dont think it can end up with ''dead" ECM, eventually you'll have to upload the original map again, i've done it only two times, both times with success for friends so i'm not an expert in this area... check the nanocom forum for more info but if you want the best and convinced to spend on it you can send the ECM to UK for remap, with DHL it can get there and come back withing a week or so.

berg450 · Nov 16, 2020

Thanks for the idea, maybe I will try it. But before I will double check if my turbo is in good shape (do not know yet how, maybe I will take it to a specialist again for checking) otherwise the remap will be useless (or at least not as sufficient as it should).

TD5 disco 2 maf and ambient air temp sensor

Dieseldog57

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