Failed inspection
09-10-2012, 05:24 PM
#16
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The oxygen sensor loop is regulating, not good enough to pass inspection, and not bad enough to get fault code 23.
Today I found a simple way to measure how good the loop is working, I used a Fluke DMM with Min/Max/Avg function. See pics. One is for the 968, and one is for my winter car. The winter car is perfect 0.45 volt average.
The spark plugs are OK.
Do you have a part#?
If I remove the tank ventilation hose on the manifold (a 5mm vacum leak) the engine almost stops, and runs very lean, about 0.2V average voltage. What does that tell me?
I think all calculations incl. temperature is integrated in the AFM. The output unit for the AFM is typical kg/h.
This is easy to test, just disconnect the sensor and the engine runs like warm, see Workshop manual.
Today I found a simple way to measure how good the loop is working, I used a Fluke DMM with Min/Max/Avg function. See pics. One is for the 968, and one is for my winter car. The winter car is perfect 0.45 volt average.
The spark plugs are OK.
you can get a cheaper volvo afm for half the price of the porsche one. works great
then induce a vacuume leak
DME thinks the air temperature is colder (denser) than it really is so need more fuel to go with it (MAF air temp sensor, NTC1, wrong
DME thinks the engine temperature is cold and that cold enrichment is called for (engine block temp sensor, NTC2, wrong
09-10-2012, 07:01 PM
#17
The oxygen sensor loop is regulating, not good enough to pass inspection, and not bad enough to get fault code 23.
Today I found a simple way to measure how good the loop is working, I used a Fluke DMM with Min/Max/Avg function. See pics. One is for the 968, and one is for my winter car. The winter car is perfect 0.45 volt average.
The spark plugs are OK.
Do you have a part#?
If I remove the tank ventilation hose on the manifold (a 5mm vacum leak) the engine almost stops, and runs very lean, about 0.2V average voltage. What does that tell me?
I think all calculations incl. temperature is integrated in the AFM. The output unit for the AFM is typical kg/h.
This is easy to test, just disconnect the sensor and the engine runs like warm, see Workshop manual.
Today I found a simple way to measure how good the loop is working, I used a Fluke DMM with Min/Max/Avg function. See pics. One is for the 968, and one is for my winter car. The winter car is perfect 0.45 volt average.
The spark plugs are OK.
Do you have a part#?
If I remove the tank ventilation hose on the manifold (a 5mm vacum leak) the engine almost stops, and runs very lean, about 0.2V average voltage. What does that tell me?
I think all calculations incl. temperature is integrated in the AFM. The output unit for the AFM is typical kg/h.
This is easy to test, just disconnect the sensor and the engine runs like warm, see Workshop manual.
Yep, MAF sensors compensate for temperature and actually do measure mass as you say. Sorry, was thinking AFM there for a minute.
Glad ruling out cold enrichment will be so easy.
'Spark plugs are OK' meaning not too sooty?
How's your search for a known good MAF coming ? :-)
Recall that is what it took to fix the high CO on my C4...
