MAF sensor
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From: In the shop cutting something up
MAF sensor
Is there any way to test the MAF. I for this online:
TESTING
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Make sure the ignition key is OFF.
Connect Breakout Box T83L-50-EEC-IV or equivalent, to the PCM harness and connect the PCM.
Start the engine and let it idle.
Use a voltmeter to measure the voltage between test pin 50 of the Breakout Box and the battery negative post.
Replace the MAF sensor if the voltage is not 0.36-1.50 volts.
But I don't have the "Breakout Box T83L-50-EEC-IV or equivalent" and I don't have any idea what it is
My truck is still running bad, (I was outside measuring how long of a line I need for the fuel pressure guage I got), and I started it up and unplugged it, it didn't run any different. But the "check eng." light came on. It hadn't came on befor.
TESTING
--------------------------------------------------------------------------------
Make sure the ignition key is OFF.
Connect Breakout Box T83L-50-EEC-IV or equivalent, to the PCM harness and connect the PCM.
Start the engine and let it idle.
Use a voltmeter to measure the voltage between test pin 50 of the Breakout Box and the battery negative post.
Replace the MAF sensor if the voltage is not 0.36-1.50 volts.
But I don't have the "Breakout Box T83L-50-EEC-IV or equivalent" and I don't have any idea what it is
My truck is still running bad, (I was outside measuring how long of a line I need for the fuel pressure guage I got), and I started it up and unplugged it, it didn't run any different. But the "check eng." light came on. It hadn't came on befor.
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Joined: Aug 2000
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From: Lockport, NY USA
The breakout box is a little boxy thing that comes with a refrigerator sized box of wiring harnesses that you install between the ecu and the ecu connector. It lets you monitor the voltage of every single engine circuit while it's running.
Your maf can cause the problems you are describing. The check engine light came on when you unplugged it because the engine is sensing an open circuit.
First you need to make sure that you have no vacuum leaks or breaks in the air tube. If any air is getting into the engine without going through the sensor it will not run right. Second, with the engine running you can lightly tap on the top of the maf and see if the truck stumbles or runs different. You could also take the sensor out of the truck and blow through it while checking hte voltage of the sensor circuit with a voltage meter, i don't have a schematic so i can't tell you which pins you need to measure from. Those are about the only easy tests you can do at home, unless you have a scantool or an ocilloscope.
-Jon
Your maf can cause the problems you are describing. The check engine light came on when you unplugged it because the engine is sensing an open circuit.
First you need to make sure that you have no vacuum leaks or breaks in the air tube. If any air is getting into the engine without going through the sensor it will not run right. Second, with the engine running you can lightly tap on the top of the maf and see if the truck stumbles or runs different. You could also take the sensor out of the truck and blow through it while checking hte voltage of the sensor circuit with a voltage meter, i don't have a schematic so i can't tell you which pins you need to measure from. Those are about the only easy tests you can do at home, unless you have a scantool or an ocilloscope.
-Jon
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From: In the shop cutting something up
One of the guys I work with has a Mac scan tool.
I hooked it up, no codes, but I did notice the O2 was showing no volts. I replaced it, but it didn't help.
I have also pulled off a vac. plug off the intake, it didn't run any different.
I hooked it up, no codes, but I did notice the O2 was showing no volts. I replaced it, but it didn't help.
I have also pulled off a vac. plug off the intake, it didn't run any different.
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Joined: Aug 2000
Posts: 1,623
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From: Lockport, NY USA
After you replaced the o2 can you read voltage from it now?
If you created a vacuum leak, by pulling the plug on the intake, and it didn't run different it's possible you have a vacuum leak somewhere. Try spraying some penetrating oil or carb cleaner around vacuum lines and the intake manifold gasket. if the engine rpms change when you spray a spot you have found a leak.
You would really need a Ford scan tool to diagnose a maf problem the generic aftermarket scanners don't give you half as much info and tests as the factory ones, they won't even read all the codes, they only pick up the codes mandated by the government.
-Jon
If you created a vacuum leak, by pulling the plug on the intake, and it didn't run different it's possible you have a vacuum leak somewhere. Try spraying some penetrating oil or carb cleaner around vacuum lines and the intake manifold gasket. if the engine rpms change when you spray a spot you have found a leak.
You would really need a Ford scan tool to diagnose a maf problem the generic aftermarket scanners don't give you half as much info and tests as the factory ones, they won't even read all the codes, they only pick up the codes mandated by the government.
-Jon