2.9 missing, code 66

[94xlt4.0]

my 90 b2 2.9 has a miss through all rpms and runs rough and even stalls out if you dont give it some gas. it has a code 66 which leads me to the maf (vane air flow/mass air flow signal low). for one what does it mean? and two how do i test the maf to make sure thats whats bad?

 

[lodden758]

try this and see if it helps, not sure if your's is like this. http://www.berrysweb.com/clean_your_maf.htm mine in my 89 has it on the fire wall with a vac running to it off the throttle body. and i believe mine is called the map senser and your is the newer maf thats on the the air intake hose like in the link posted

 

[94xlt4.0]

yeah i already tried that and it didnt make a difference

 

[n_grimm]

You said it is missing thru all rpms. Does the engine shake like one cylinder is missing? If so I would try to determine which cylinder it is by pulling one plug wire at a time. That will give everyone an idea as to the kind of miss you are referring to.

 

[94xlt4.0]

plugs and wires are all new, new cap and rotor, timing set at 10*, new tps. the only thing not new is the maf which is why im asking how do to test it, also will a maf from my 94 4.0 work on the 2.9?

 

[Psychopete]

plugs and wires are all new, new cap and rotor, timing set at 10*, new tps. the only thing not new is the maf which is why im asking how do to test it, also will a maf from my 94 4.0 work on the 2.9?

Unless you can flow a known amount of air flow through it, there is no reasonable way to test it - but can at least check for +12v and ground to the sensor. However, the DC voltage to the computer should read as the air flow does.

Edit:
No, you won't want to use that mas from your '94.

 

[94xlt4.0]

ok, i tested the maf according what i found on alldata and the was "bad" allegedly so it has been replaced. the b2 will idle fine now but sounds like a slight miss still. im going to pull the plugs to inspect them and test the resistance on the wires. if they are fine then the problem may be coming from my cat that has been gutted by the previous owner. it always had a slight lope like it had a cam but i attributed that to the cat which is what may be what i hear now. its dark and raining now so hopefully a road test tomorrow or the next day