Golf tdi pd 100 (ATD)

[hsntdipd100]

The way i am testing the Mass Air flow is connecting the vehicle to Vag com get the menu up rev the engine at stnad still and that then measures the air flowing threw the MAF sensor and that is whats wrong the reading on my vehicle is low even when i put a new MAF sensor on my vehicle. somthing is causing the readings to stay low on the air mass meter.

To reset the learn values i get it done from awesome gti they connect it to vag com and there is a button on the screen which says reset. I have seen them reset it but not sure on exact steps. do get what i am saying? lol

[Nutty]

You are testing the MAF incorrectly

Air system part I: MAF

• Go into Engine measuring block 003
• Start Logging data
• In a high gear (4th/5th), give full throttle from 2500 rpm up to 3500rpm.
• Find and Open the Log file in Windows Explorer
• Graph MAF actual -vs- rpm in Excel
• The MAF is OK if the actual value is at least 850-900 mg/h at 3000 rpm.

Half way down the page ;-)

http://www.ross-tech.com/vag-com/cars/tdi.html

[hsntdipd100]

Hi, ure right u get a better reading when u get on road than stand still but even out on raod and on rolling raod the MAF sensor wont give out more than 650-700 mg/h even with a new air mass meter? i get a power increase but readings still low.

I have discoverd an air noise form the back on my engine as if its leaking from around manifold or intake am going to get that cehckd tomorw u rekon that can drop the readings? Its sounds right i think as if some sort of air is escaping from some where becuase I have changed nearly every sonsor on the vehicle. Fingers crossed hey!cheers.

[hsntdipd100]

I have found out that the down pipe flexi is leaking, i know this can result in power loss but how much would you say? hmmmm

[dod1e]

If you are loosing boost then that will definately cause a loss of power and result in low power, as less air fed into engine = less oxygen for combustion = less power and less exhaust gasses to drive the turbo = less overall air flow through the engine = viciuous circle resulting in the symptoms you describe.

Dont know the ins and outs of these specific engines but if yo u can measure the MAF readings surely you can measure the boost readings?

If the ECU measures lower boost then it probably restricts fueling also to prevent black smoke.

Dod

[Nutty]

I have found out that the down pipe flexi is leaking, i know this can result in power loss but how much would you say? hmmmm

If im reading this post correctly, you have had the car into awesome gti a few times for them to check out your problem, they have failed to notice this defect but carried on to reset the ECU with VAGCom

I assume by the term down pipe you mean the exhaust system ? the down pipe is placed after the turbo, where did you get the info that a leaking flex will result in power loss, If the flex were leaking enough to cause you a problem you would be able to hear it straight away.

[hsntdipd100]

awesome gti just say book the vehiclein an every time i go thr he jus walks around wiv a spanner and a maf sensor and then goes toilet and says its stange? every time then they say book it in for another hour to me i thikn ther jus takin the 'p i tipple s' i herd air leaking from the back of the engine so i took it to the local garage and he told me ure exhaust dwn pipe has gt i leak i cehked it and its blowin air.

I have orderd a miltek large bore down pipe should be here soon. Wud u kno why or what cud cause a MAF snsor 2 read low? cheers.

[dod1e]

Appologies, I assumed you meant the pipe from the turbo to the intercooler. If you can hear a gas leak from the exhaust is it coming out under a lot of pressure?

Maybe there is a partial blockage in your exhaust, such as a coked up cat convertor which would cause you to lose power, and may have caused the leak.

Again, i'm guessing.....

[hsntdipd100]

possibility, well i have ordrd a large bore down pipe (miltek) it has the high flow cat. see how it goes fingers crossed, in terms of MAF readings i am still stuck! i dont kno what to do. cheers.

[dod1e]

well, if there is a restriction in your exhaust, this could restrict overall airflow through the engine and give low MAF readings.....