please help

[Spikey]

I have just replaced the rubber air inlet for a metal one and also taken the boost solenoid off. Ran it and it cuts out. Unplugged the afm and it runs fine. Plug it back in and it cuts out. I have not touched the afm. What could it be?

 

[Pulsey]

Have you dropped the afm or knocked it? They can be very fragile

 

[pulsar brum]

they are very fragile indeed and sensitive umust have tapped it replace the air flow. then tryit again. i couldnt be asked to change mine so i went for a link ecu and runs flowless

 

[Spikey]

Do the symptoms sound like the maf? How come it revs fine with no afm connected? Thought it would overfuel.

 

[PobodY]

That is an odd one - you should only get limp mode with no AFM connected.

 

[Spikey]

Well i put the std rubber induction pipe back on and its running fine.

 

[geoff pine]

So you just need to work out whats so different that it gave you those symptoms have you moved it to close to the turbo ? have you used a straight pipe with no bends ? is the wire now stretched tight just some ideas .

 

[Spikey]

used a Alloy pipe with only one bend. But that should no make a Difference?

 

[PobodY]

Could be a turbulence issue. Nissan use a MAF which might get upset by non-laminar flow - basically it uses a hot wire which then has a change in resistance when the air passes over it; if it's not flowing nicely across it because of turbulence, then it gives a dodgy signal.

This may sound odd, but try turning the MAF around so that the hot wire is in a different position; that might be enough to get a good signal out of it.

 

[jambo_gtir]

Surely if there was an issue with turbulence, it would occur after the sensor, as the sensor is the first thing the air passes through?
what's the ID of the new pipe? if it's larger than the the standard then that might cause issues?
Might sound obvious but don't forget the standard pipe has vaccume pipes plumbed in to it (Re-circ valve, boost solanoid and engine breather i think)...... if you put a new metal pipe on and it doesn't have those it might cause issues.