Ambient Air pressure sensor question, sluggish D2

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genarrover

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Hello, I have just acquired a Disco 2 td5 auto off my friend. It has a bell auto services installed vgt turbo, boost box, decat, egr remove, full stainless turbo back, bigger intercooler and I cant believe how awful it is. I have nanocom on it and am looking around. I live at sea level and the Ambient Air pressure sensing is showing approx 890kpa, I also have a large hill behind my house and it is adjusting by about 10 kpa across 400 feet. Expecting 1013kpa at sea level, would this create a massive lag at low rpm?
 
Clean it with contact spray and forget about it as long as it works cos as you have a boost box which alters the MAP reading the AAP reading is almost useless, important is to not be open or closed circuit to send the ECU to default ... the 1013Kpa is a standard refference pressure used for calculations, the ambient pressure is variable according to weather conditions...if you want to check the AAP sensor's accuracy compare with a barometer reading
 
Last edited:
sierrafery said:
Clean it with contact spray and forget about it as long as it works cos as you have a boost box which alters the MAP reading the AAP reading is almost useless, important is to not be open or closed circuit to send the ECU to default ... the 1013Kpa is a standard refference pressure used for calculations, the ambient pressure is variable according to weather conditions...if you want to check the AAP sensor's accuracy compare with a barometer reading
Click to expand...

Hello, thanks for that, good advice. I looked at the boost box and decided I didn't like it so I chopped it off and bypassed, hey presto! Disco went great! Off to the shop! On leaving the shop (10 mile) driver demand problem logged low (current), won't clear. nanocom showed MAP as 0.0v 100kpa going home at 30. :) At least it is properly broken now. Before that it was showing 1.23 bar and 620 on the MAF on throttle going great. Anyone got a good place to buy map sensor? Thanks
 
You might need to adjust down the watstegate if you got rid of the boost box cos it can go to overboost now so if it cuts out under heavy load adjust the rod to be longer a bit.,, usually driver demand fault code is triggered by faulty throttle position sensor
 
sierrafery said:
You might need to adjust down the watstegate if you got rid of the boost box cos it can go to overboost now so if it cuts out under heavy load adjust the rod to be longer a bit.,, usually driver demand fault code is triggered by faulty throttle position sensor
Click to expand...

Indeed, overboost right away, nanocom cleared it. Bad connection on my part for the MAP fail, fixed it. What is the threshold for overboost. I have also noticed the egr and wastegate modulation are still active, what hardware do I need to disable them as they are redundant?
 
You need a proper remap with uprated MAP sensor to suit that VNT turbo, you can't disable EGR or wastegate modulators management other way ... the overboost limit with std fuel map is 242Kpa
 
genarrover said:
Indeed, overboost right away, nanocom cleared it. Bad connection on my part for the MAP fail, fixed it. What is the threshold for overboost. I have also noticed the egr and wastegate modulation are still active, what hardware do I need to disable them as they are redundant?
Click to expand...
I didn't see it hit 242 but will look in the log file, someone either alive or bell did the remap and egr/wg delete so I would have hoped they did what was paid for. Guess not....
It logged the overboost but didn't go bag to limp
 
It doesnt go to limp on overboost, the ECU reduces fuelling for a short time untill the MAP reading is restored to normal... the real thing is a remap with increased overboost limit and higher pressure MAP sensor, the boost box thing is not "healthy" at all
 
genarrover said:
I didn't see it hit 242 but will look in the log file, someone either alive or bell did the remap and egr/wg delete so I would have hoped they did what was paid for. Guess not....
It logged the overboost but didn't go bag to limp
Click to expand...

Hear hear! I haven't looked in it yet but I can guess, lack of modulation disturbed me straight of, being an audi 20v owner. I've found the td5 map editor suite and need to look at it. what hardware can properly do the delete/map?
 
sierrafery said:
It doesnt go to limp on overboost, the ECU reduces fuelling for a short time untill the MAP reading is restored to normal... the real thing is a remap with increased overboost limit and higher pressure MAP sensor, the boost box thing is not "healthy" at all
Click to expand...
Please excuse the quote myself thing, don't quite know the forum front end.
On reflection, I felt the fuel cut when it didn't like my planted foot.
 
That map editor of nanocom can be used only if the ECU is NNN..... type(post 2003 modells), doesnt work on MSB, dont bother too much with that EGR and wastegate modulation thing, it doesnt affect anything at all, just appears in the live data and it's not about hardware to get rid of them but about a fuel map which can be loaded with nanocom or if it's MSB ECU the chip must be changed
 
sierrafery said:
That map editor of nanocom can be used only if the ECU is NNN..... type(post 2003 modells), doesnt work on MSB, dont bother too much with that EGR and wastegate modulation thing, it doesnt affect anything at all, just appears in the live data and it's not about hardware to get rid of them but about a fuel map which can be loaded with nanocom or if it's MSB ECU the chip must be changed
Click to expand...

I will have a look at the ecu type, age suggests MSB. If that is the case I will be back! :) Cheers!
 
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