Bosch Jetronic Maf

[Project205 0]

Hi,

 

I have checked the resistance readings for my Jetronic MAF at idle position between pins 5 and 7. The expected result is 60Ohms, mine came in at 200Ohms. (ref: article on 205drivers.com)

 

Obviously this means a higher resistance, which could mean dirt on the track or worst case a worn track. My GTi has covered only 23,000 miles so if I open the top of the unit, I would hope a careful clean will fix this.

 

What I am interested in is:

1. what should I clean it with (I have been advised to avoid carb cleaner, too strong)

and

2. what effect would this additional resistance have in terms of the idle at this position - i.e. what message would this send the ecu? I imagine it would think it the air flow is higher than it actually is and that additional fuel should be thrown in?

 

Love to hear your thoughts and suggestions on cleaner.

 

Thanks

[rallysteve 22]

Hi,

 

I have checked the resistance readings for my Jetronic MAF at idle position between pins 5 and 7. The expected result is 60Ohms, mine came in at 200Ohms. (ref: article on 205drivers.com)

 

Obviously this means a higher resistance, which could mean dirt on the track or worst case a worn track. My GTi has covered only 23,000 miles so if I open the top of the unit, I would hope a careful clean will fix this.

 

What I am interested in is:

1. what should I clean it with (I have been advised to avoid carb cleaner, too strong)

and

2. what effect would this additional resistance have in terms of the idle at this position - i.e. what message would this send the ecu? I imagine it would think it the air flow is higher than it actually is and that additional fuel should be thrown in?

 

Love to hear your thoughts and suggestions on cleaner.

 

Thanks

 

Hi there, to clean it use either some rubbing alcohol or some electrical contact cleaner. Not too sure about your second question, but i thought the AFM only came into play when above idle. Thought idle fuel was dealt with by the SAD and throttle switch.

 

Cheers Steve

[welshpug 1,737]

The SAD has nothing to do with fuelling directly, its purely the AFM + Throttle Switch and a speed signal from the distributor.

 

The more the SAD is open (i.e cold engine) the more the flap on the AFM will open due to more air going in.

[Miles 331 1 Cars]

If you do open it up be careful what you seal the lid with as allot of RTV's corrodes electrical parts

[Project205 0]

If you do open it up be careful what you seal the lid with as allot of RTV's corrodes electrical parts

 

Thanks for the advice guys.

 

Any suggestions on sealant?