Pulled codes now I need your help!

[GM H8R]

Basically the car idles like ***** and the check engine light in on. In short 3 days ago while cruising about the car died as I stopped at a red light and the check engine light came on. It refused to fire up without a bit of feathering of the throttle as if it was flooded and it would run but not idle. The check engine light went out on my way home but came on again as I let the car idle in the garage before it quit. The next day I started the car and went for a very short drive without a problem but the check engine light did flash at me once briefly. Yesterday I started the car the check engine light was on right away and the idle was crap and it smells a bit rich.

Today I pulled the codes (KOEO) and got :hard fault 67, continuous memory fault 41, 66, 91, and 96.

From the book:
67 = neutral drive switch circuit failure, circuit open; or A/C input high whatever the hell that means?
41, 91 = HEGO sensor signal out of range - always lean
66 = mass airflow sensor fault - below minimum voltage
96 = fuel pump secondary circuit fault / high speed fuel pump relay open

Next I cleared the codes and disconnected the battery for a few minutes, reconnected the battery and started the car. Same poor idle and check engine light.
I pulled the codes again and got: hard fault 11, continuous memory fault 15 and 66.

11 = system OK (good news)
15 = power interuption to computer memory or EEC, keep alive memory test failed (sounds OK as I just had the battery disconnected)
66 = mass airflow sensor fault - below minimum voltage (same as before I cleared the codes)

I'm thinking the problem is with the MAF, I currently have a 75mm Bullet cal for 24#. I have had this meter for about 8 years and it has been back to Pro-M once for a recal (19 to 24#) about 2 years ago. Do these things just go bad? Is there any way to check the MAF? Does anybody have any thoughts on the other HEGO lean codes?

Jason

 

[sublime29]

Hello! Since you cleared the codes.What is it running like?If still same problem I would guess the mass air flow.Just for kicks try your old one just to see what it does and if it runs check codes.Remember to clear codes be for the switch. Later sub

 

[GM H8R]

Yeah, I cleared the codes and fired it up with no change. Check engine light came on right away and the code indicated low voltage from the MAF. I don't have the original MAF to plug in and try, any other ideas?

Jason

 

[jrichker]

Code 66 MAF below minimum test voltage.
Insufficient or no voltage from MAF. Dirty MAF element, bad MAF, bad MAF wiring, missing power to MAF. Check for missing +12 volts on this circuit. Check the two links for a wiring diagram to help you find the red wire for computer power relay switched +12 volts. Check for 12 volts between the red and black wires on the MAF (usually pins A & B).

There are three parts in a MAF: the heater, the sensor element and the amplifier. The heater heats the MAF sensor element casing the resistance to increase. The amplifier buffers the MAF output signal and has a resistor that is laser trimmed to provide an output range compatible with the computer's load tables.

The MAF output varies with RPM which causes the airflow to increase or decease. The increase of air across the MAF sensor element causes it to cool, allowing more voltage to pass and telling the computer to increase the fuel flow. A decrease in airflow causes the MAF sensor element to get warmer, decreasing the voltage and reducing the fuel flow. Measure the MAF output at pins C & D on the MAF connector (dark blue/orange and tan/light blue) or at pins 50 & 9 on the computer.

At idle = approximately .6 volt
20 MPH = approximately 1.10 volt
40 MPH = approximately 1.70 volt
60 MPH = approximately 2.10 volt

Check the resistance of the MAF signal wiring. Pin D on the MAF and pin 50 on the computer (dark blue/orange wire) should be less than 2 ohms. Pin C on the MAF and pin 9 on the computer (tan/light blue wire) should be less than 2 ohms.

There should be a minimum of 10K ohms between either pin C or D on the MAF and ground.

Remember that the computer does not source any power, but provides the ground necessary to complete the circuit. That means one side of the circuit will always be hot, and the other side will go to ground or below 1 volt as the computer switches on that circuit.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

 

[sublime29]

Hello! Sounds like the mass air flow sensor is bunk.I would send back and get it fixed or check ebay for one.Guess the stang is taken some R&R for awhile later sub