Pages: [1]
Author Topic: Stock Jetta high maf Q  (Read 2985 times)
TijnCU
Hero Member
*****

Karma: +60/-4
Offline Offline

Posts: 690


flying brick


« on: November 24, 2015, 02:31:41 AM »

I started working on a Jetta Automatic with numerous errors and heavy fuel consumption (avg 9km/l). After fixing the hardware issues, I scanned it code free.
Took it for a drive, and logged it. I had multiple attempts, but the logger kept crashing for some reason. I only had limited time before the car had to be returned, so not much data is collected.

What I could see was that the MAF was way too high, but I confirmed the mapping to be stock. LTFT is +12%, STFT around 2%. It does not make sense to me that the corrections are positive, since it is overfueling badly.  My other ecu's correct LTFT to negative numbers when rich. The high maf is causing PS_w to go sky high, flooding the cilinders with petrol (injector DC over 100%  Grin) and also running less timing than optimal.

Just to confirm before spending 150€ on a new MAF: can a defective MAF cause these high readings? I have previously only had them reading low.
The MAF is an OEM bosch wideband model (06A906461L) that matches the car, I checked the sensor inside as well to be sure. After 100km, there where no fault codes present.
********
Update: this car has been fitted with a new maf, and was then sold before I could do another log.  Lips sealed
Consumption was still bad according to the owner, but don't know if there was any improvement.
Case closed Shocked
« Last Edit: December 16, 2015, 06:37:27 AM by TijnCU » Logged

Pages: [1]
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.012 seconds with 16 queries. (Pretty URLs adds 0.001s, 0q)