[V8] Mass Air Flow Sensor

[Jeff Goldberg]

My '91 has been down for a long time . The car runs fine cold.  The
colder it is the longer I can drive it.  It also idles fine.  As
soon as temp gauge reaches the  mark between 50c and 100c it starts
to surge/miss with no power.

 

 I did a little troubleshooting today and found the voltages on the
MAF to be out of the ranges called for in the manual.  

 

I'm getting the following voltages:

 

Key on, engine off is 1.4v, Bentley says "must be between 1.3v and
1.6v"  so OK here

 

Idle is 2.46v,  Bentley says "approximately 2.5"  it would seem OK
here

 

Apply throttle 2.6-2.8v, Bentley says "voltage must increase to 3 to
5 volts."  NOT OK here

 

I was getting even less at throttle on my first test and cleaned the
MAF contacts with 1500 grit paper and got 3.2 volts when it was
cold.  But it seems the warmer it gets the lower the voltages go and
2.8v is max that I am seeing with the engine warm.

 

Is a used one a good choice?  A search of the net turned up
directauto.com offering a rebuilt one for $152.80.  Anyone have any
BTDT with rebuilt MAF sensors?

 

Jeff