Maf question

teeth2k

Full Member
Feb 8, 2003
908
0
sussex
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How is the best way to tell if the maf is miss behaving?
1.9 TDI
I can start the car with it unplugged

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Jay1601

Active Member
Feb 23, 2018
73
7
Specified will be the figure the car is wanting to see but google might give you a rough idea on what it should be
 
Oct 28, 2017
25
0
Ok thanks, you wouldn't know where to find the correct values ?


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When pulling from low rpm 1500 at full load in 3rd gear all the way to around 4K rev., the MAF should exceed the max. MAF spec in group 003. you're looking < 850mg/ str. The flow will drop off slightly as you reach peak power.

Might be worth looking on channels 10 and 11 to see what specific boost pressure you're getting too.

What are the symptoms that make you think your MAF is dead?
 

teeth2k

Full Member
Feb 8, 2003
908
0
sussex
Visit site
When pulling from low rpm 1500 at full load in 3rd gear all the way to around 4K rev., the MAF should exceed the max. MAF spec in group 003. you're looking < 850mg/ str. The flow will drop off slightly as you reach peak power.

Might be worth looking on channels 10 and 11 to see what specific boost pressure you're getting too.

What are the symptoms that make you think your MAF is dead?
The car wouldn't start, called out the breakdown chap who got it started with a can of lynx and said the glow plugs were at fault, took it to the garage and they said glow plugs were fine but the battery had had it, also said the maf was at fault, I had a new battery fitted and told them to leave the maf, scanned it on vcds and found a maf fault, removed it and cleaned it with some electronic cleaner, refitted, cleared the code and so far it hasn't come back, I often use the torque app and scan often for faults but unit the car wouldn't start never found a maf one.
So just wanted to check the value s


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Oct 28, 2017
25
0
The car wouldn't start, called out the breakdown chap who got it started with a can of lynx and said the glow plugs were at fault, took it to the garage and they said glow plugs were fine but the battery had had it, also said the maf was at fault, I had a new battery fitted and told them to leave the maf, scanned it on vcds and found a maf fault, removed it and cleaned it with some electronic cleaner, refitted, cleared the code and so far it hasn't come back, I often use the torque app and scan often for faults but unit the car wouldn't start never found a maf one.
So just wanted to check the value s


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You don't mean to clean them at all.

Sound a bit suspicious to me. Most likely it has been caused by using the aerosol as a cold start when the intake was disconnected and the fault hasn't been cleared.

You can run it with MAF disconnected however, the value will default to > 750mg/str. so your power will be restricted.

Hope that clears things up.
 
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