Air Mass Meter

[PFS]

Hi,

Just trying to sort out a prob when cold starting. Runs like it's only firing on 3 for a few minutes then all fine.

Question is, what does the sensor on top of the air mass meter do ? cos if I disconnect the plug from it nothing changes ? the engine runs fine with or without it.

To date, I have cleaned out the throttle body and it's nice and shiny clean. Replaced the ecu temp sender on the top hose and fitted new plugs and sprayed damp start on the leads.

In case it was a water leak into a pot, I have removed all plugs and spun the engine over 30 secs before starting. This made no difference to the cold start prob. The plugs are running a good colour and are not wet or oily. The Engine is an 8V 2.0 ltr ADY and does around 38 -40 mpg on a run at sensible speeds. No oil in water and no water on dip stick. Done 150K. Any tips much appreciated.

Cheers
Scotty (PFS) I tried to log iin as scotty but someone has beat me to it...so I am PFS on this forum.

[rubjonny]

if it runs just as well without it plugged in, then its working fine. try disconnecting the lambda probe next. if it runs better without, replace it.  ecu temp sensor is also a prime suspect, as is coil. crank sensor may be faulty, but generally it would run bad all the time rather than get better once warm

[PFS]

hi,
Many thanks for the info, will try the lambda probe next.
Dumb question, but if the engine works without the air mass sensor - is it not needed ?  I cant get my head round that one .
Sorry to sound thick, just a novice at these things ( was brought up on moggie 1000's and A35's ) and SU carbs that I could understand.!
Cheers
Scotty

[javalin]

no - you need the lambda/O2 and the air mass meter (MAF) to get the ECU to fuel the engine correctly.  All that un-plugging them does - its make the ECU substitute default values for them.

Sounds like you also need to change the rotor cap and arm, but also sounds a bit compression'y.

James

[PFS]

Hi,

Forgot to mention, new disi cap and arm have been fitted. they were well worn.

will check cylinder compression (cold) next.

thanks.

[javalin]

interesting.  Let us know what you find...

J

[PFS]

Well,  I seem to going backwards now as 2 miles from the home the engine oil and ign lights came on and the engine just died   

It started ok at the first attempt but then ran very lumpy - so I dashed home while I could. This is a new symptom for me.

Any ideas would be much appreciated.

Before this happened I was going to check compressions but have not done that as yet. I was also going to check the 2 relays which get mentioned in many post.  I can see the fuses but how do you get at the relays ?

Cheers

[rubjonny]

kinda sounds like crank sensor, if the cable looks ropey get it replaced

[PFS]

Thanks - will check it out in the morning.