Air flow meter?
10-27-08, 11:19 PM
#1
Full Member
Thread Starter
Air flow meter?
Okay so I was just wondering what are the air flow meter hailers? Why do people say unplug air flow meter and see if it sparks? What does the Air Flow meter have to do with spark? Also does this mean that I would need a new Afm?
10-27-08, 11:29 PM
#2
The air flow meter measures the incoming volume of air and sends resistance values to the ecu so it can provide the correct amount of fuel.
Hailers is a forum member, not a part.
If someone told you to unplug the AFM to test spark, that would be because a disconnected AFM would keep the fuel pump from running, which would mean the engine would simply turn over, but not start.
Hailers is a forum member, not a part.
If someone told you to unplug the AFM to test spark, that would be because a disconnected AFM would keep the fuel pump from running, which would mean the engine would simply turn over, but not start.
10-27-08, 11:36 PM
#3
The air flow meter measures the incoming volume of air and sends resistance values to the ecu so it can provide the correct amount of fuel.
Hailers is a forum member, not a part.
If someone told you to unplug the AFM to test spark, that would be because a disconnected AFM would keep the fuel pump from running, which would mean the engine would simply turn over, but not start.
Hailers is a forum member, not a part.
If someone told you to unplug the AFM to test spark, that would be because a disconnected AFM would keep the fuel pump from running, which would mean the engine would simply turn over, but not start.
the engine will and does run. the reason why they say remove it when your not getting spark for some odd reason yet when you test it to the nth degree, all the tests come back positive, then the airflow meter is at fault. it has some circuit (not going to search for it) that prevent the coils from fireing.
10-28-08, 04:56 AM
#4
HAILERS
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In some cases on this forum, the person did not get spark. He then found out that if he disconnected his AFM, then he had spark. The only reason I can see for him to not get spark, is if the ref voltage to the afm was shorted to gnd or really being drawn down by an internal problem in the AFM.
A similar thing happened on this forum last week. In this case the man had no spark, and after a while, he found if the TPS was disconnected, then he had spark. He had spliced in extra wire to lengthen his TPS harness and had gotten the wires repliced in wrong. Killed the ref voltage. Which kiled the ability to make spark or inject fuel.
Most of those sensors for the engine have a brown/white wire. All those brown/white wires are spliced together inside the harness, and come from the ECU. If you have* something *dragging down that ref voltage, then the ECU can't make spark. It's easy to see if this is your problem. Just pull the plug off the boost/pressure sensor and put a meter on the brown/white wire and see if it has approx 5vdc or not. If you see something like 2vdc, tough. It ain't a gonnal make sprak. Either the ECU is corrupt or one of those items using the ref voltage is dragging the voltage down.
So you can sorta understand why someone might pull the plug off the afm. IT's an easy way to see if the afm is killing the 5vdc or not. Same with the guy who pulled the TPS plug off. It was a easy way to find out which item was pulling the ref voltage down.
A similar thing happened on this forum last week. In this case the man had no spark, and after a while, he found if the TPS was disconnected, then he had spark. He had spliced in extra wire to lengthen his TPS harness and had gotten the wires repliced in wrong. Killed the ref voltage. Which kiled the ability to make spark or inject fuel.
Most of those sensors for the engine have a brown/white wire. All those brown/white wires are spliced together inside the harness, and come from the ECU. If you have* something *dragging down that ref voltage, then the ECU can't make spark. It's easy to see if this is your problem. Just pull the plug off the boost/pressure sensor and put a meter on the brown/white wire and see if it has approx 5vdc or not. If you see something like 2vdc, tough. It ain't a gonnal make sprak. Either the ECU is corrupt or one of those items using the ref voltage is dragging the voltage down.
So you can sorta understand why someone might pull the plug off the afm. IT's an easy way to see if the afm is killing the 5vdc or not. Same with the guy who pulled the TPS plug off. It was a easy way to find out which item was pulling the ref voltage down.
Last edited by HAILERS; 10-28-08 at 04:59 AM.
10-28-08, 03:06 PM
#6
HAILERS
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Location: FORT WORTH, TEXAS,USA
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Make sure the EGI fuse is good and while looking make sure all the fuses are good.
Pull the small, white, two socket plug off the LEAD coil assy. Key to ON. See if there is batt voltage on the black/yellow wire. It should be there.
IF it's there, go to the boost/pressure sensor. Pull that plug off. Key to ON. See if there is approx 5vdc there.
I'll stop there and wait to see what you have.
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