Hi had problems with air flow sensor few years back, think some one showed me where to find it & check to see if that was the problem.But i can't remember what they said now. Any way symptoms are the same so can any one help me please.

 

losing power

 

Am I correct that you are losing power during acceleration?
What is model year and mileage?
I have two (2) passats ('90 16V and '98 1.8T) and both air flow sensor units are located in the same area as the air filter.
The '90 unit has the flow sensor incorporated into an aluminum housing whichhas the fuel distributor and intake air boot assembled and mounted onto the upper air filter housing.
The '98 Passat flow sensor is an independent or stand aloneunit which is position on to front portion of the air filter housing.
The '90 unit have had various issue with loss power;
A) Misfiring in cruising modewhenambient temperature and humidity (80°F/60% humidity) are high. Replaced air flow sensor and problem resolved
B)Intermittent misfiring in cruising mode, non-temperature/humidity related, eventually breaking down. Replaced fuel pump and problem resolved.
C) As problem as "B" without the break-down. Air horn boot had cracked resulting in vacuum leak and problem resolved.
D) Presently '90 is misfiring under load once engine/coolant temperature at normal operating temperature. Checked out fuel system, differential, and residualpressurefueldelivery/flow and electrical circuit allare within spec. Replaced coolant temperature sensor problem still present.Next step is toreplace oxygen and knock sensors should have completed by midweek. Still not resolved will check-out the vacuum system and fuel injectors.
After that only thing let is a faulty fuel distributor, air flow sensor, or the Motronic system.