Technical What causes low Actual Air Intake Quantity on 115JTD

[SillyBilly]

Hi
Old problem: I had a smokey 'throttled' engine but have now found that the intake pipe had come off the intercooler. It now runs fine.
New problem:
When I use Fiatecuscan to check the parameters Actual Intake Air Quantity and Desired Intake Air Quantity, I find that the Actual readings are between 10% and 20% of the Desired.
I have swapped the MAF sensor with that on another 115JTD and the figures for Actual Air Intake Quantity on both are the same as they were, so not the MAF sensor.
I have checked the EGR valve and cleaned it out, though it wasn't blocked or stuck.
I have checked the Intake Butterfly valve and it isn't stuck.
I have checked the pipes and connectors.
The car passed its MOT emissions test last week
Any help would be appreciated. Help!

 

[momoe]

When you say "runs fine" do you mean it doesn't smoke anymore but is still throttled or performance is as you would expect?
If the performance is normal, then I would suspect the MAP sensor is faulty, this is the sensor on the inlet manifold at the back of the engine to the left of the EGR. This measures manifold pressure so I'm assuming this would be the sensor supplying the air quantity readings - good news is it's easily accessible and relatively cheap.
Try swapping this with your other Multipla and see what happens.

 

[SillyBilly]

Hi
It runs as I would expect with no smoke or hesitation. I will try swapping the 2 MAP sensors tomorrow
Thanks

 

[fraguzz]

have the same problem..

but the Air Q is measured by the MAF not the MAP.. maby the car is reading high boost pressure on a faulty MAP and therefore expecting more air at a given boost.. but my MAP reads 1010 when not on boost.. so dont think that is faulty..

 

[SillyBilly]

Hi
I had said MAF inmy original post but MOMOe said to check the MAP sensor so I did.
Thanks