Maf

[peterchurch]

Hi,
on a couple of occasions I have had a fault on my car. The simptoms are:

The engine sounds like it is misfiring / rough

It will only rev to 3,000

No power...

It only ever happens when the car is cold...

Switch off the engine and restart and the fault is gone

I have had the car in for an A service and had the MAF sensor checked while it was in

I readings were

Standing (engine off) ...

air temp 15 oC
Engine Temp 11 oC
Injection duration (bank1) 0.00 ms
Injection duration (bank2) 0.00 ms

Standing (Engine Running)

air temp 13 oC
Engine Temp 18 oC
Injection duration (bank1) 6.73 ms
Injection duration (bank2) 6.42 ms

No error codes stored...


Any thoughts ?

Regards,

Peter

 

[Dieselman]

But what were the MAF readings?

 

[peterchurch]

Those were the Maf sensor readings... the engine temp is the temp reading according to the mass air sensor ...

 

[Captain Peacock]

Hi,
on a couple of occasions I have had a fault on my car. The simptoms are:

The engine sounds like it is misfiring / rough

Could this be the same fault, sitting in traffic after 8 mile journey, in D holding with footbrake, decided to flick it into P till traffic set off, as soon as I put it in P I got a misfire, rough idle, put it back into D, tickover was ok, back into P same thing again misfire/rough idle. if I pressed the throttle It seem to die [in P]and no throttle responce, once I set off it has never done in again. I have had trouble with the key transponder battery connections a few days ago, could that affect anything, any thoughts, would the faults store??

 

[peterchurch]

Could this be the same fault, sitting in traffic after 8 mile journey, in D holding with footbrake, decided to flick it into P till traffic set off, as soon as I put it in P I got a misfire, rough idle, put it back into D, tickover was ok, back into P same thing again misfire/rough idle. if I pressed the throttle It seem to die [in P]and no throttle responce, once I set off it has never done in again. I have had trouble with the key transponder battery connections a few days ago, could that affect anything, any thoughts, would the faults store??

It does sound the same sort of engine resonce although mines only ever from cold I would have expected them to register as a misfire on the respective cylinders, But my car had no errors at all yesterday despite having it happen on Thursday

 

[Dieselman]

Those were the Maf sensor readings... the engine temp is the temp reading according to the mass air sensor ...

But that is meaningless info. What you need is the volume of air passing the MAF compared to specified data.

 

[peterchurch]

But that is meaningless info. What you need is the volume of air passing the MAF compared to specified data.

oh! will need to ask the chap when I get my disks and pads changed next week...

 

[zerocool]

maf doesn't normally log a fault when it goes wrong,the symptoms you are giving point towards the maf sensor.
normally we have a spare one in the workshop which we use a testing tool

 

[peterchurch]

maf doesn't normally log a fault when it goes wrong,the symptoms you are giving point towards the maf sensor.
normally we have a spare one in the workshop which we use a testing tool

Cheers I will go and get one, and try it out. At least if it doesn't cure it I know that my maf will never fail while I have a spare in the garage

 

[peterchurch]

I got the MAF Swapped today and I would guess that It has been buggered from the day I bought the car !!! I can now get ESP to kick in just by booting the car hard in a straight line I got told off for pulling donuts (ESP off) in a gravel car park on the way home

Loads of fun