What Does The Airflow Meter Do?

[sffans]

I have a 93 es300 And I was just wondering what the purpose of the air flow meter is? Could a bad airflow meter keep your car from running if you give it gas? When i plug mine in it makes the car die. Thanks

[Kauz]

As the name implies, the Mass Air Flow Meter measures the volume of air going into the engine. The engine's computer uses this information to maintain the ideal air/fuel ratio of 14.7-to-1. If this meter is not functioning properly, then your car will not run optimally or not run at all depending on how off the meter is. You could swap the Mass Air Flow Meter with another car if there is one available as a way to confirm the source of the problem.

[wwest]

I have a 93 es300 And I was just wondering what the purpose of the air flow meter is? Could a bad airflow meter keep your car from running if you give it gas? When i plug mine in it makes the car die. Thanks

The primary purpose of the MAF/IAT, Mass Air Flow and Intake Air Temperature, combined module is to control the enriched mixture level that is typically used above idle, and especially at or near WOT. The "upstream" exhaust oxygen sensor is used to control the mixture at idle but with the mixture enriched above idle and outside the range of the oxygen sensor the MAF/IAT is used.

At idle the MAF/IAT and oxygen sensors are cross-checked against each other, but the oxygen sensor signal RULES at idle.

Go back and plug the MAF/IAT sensor in while the battery is disconnected, wait ~5 minutes and then reconnect the battery and the engine should now start and run.

[sffans]

OK thanks I tested the maf and it is bad so Im getting anthor one tomorrow will let you know if that cures the problem Thanks

[Toysrme]

I so highly doubt that unless you've ripped the wire harness out by accident.

[sffans]

Got a new maf and it did not cure the problem. Not sure what to do next.

[Toysrme]

it's because whoever is troubleshooting your car doesn't know how it works to begin with. take your new afm & get your money back.

check for vacuum leaks, then check the fuel pressure

[sffans]

the car idles fine its just when i give it gas or plug in the maf that it dies. Would that be a vacuum leak or fuel pressure? I could not find a leak or hear one. all the vacuum lines are good. Yes and i will get my money back on the maf. Any more help would be greeted. Thanks

[Toysrme]

check for vacuum leaks, then check the fuel pressure

and to add to that, your engine won't run at all without the afm connected for more than it takes for the coolant to come up to temperature.

you're running solely on the cold start injector & residual fuel pressure. When the AFM is not plugged in you loose the fuel pump (The activation switch for the fuel pump relay is not connected & tripped), and the injector pulse widths stay at 0.0ms. As in.. they don't squirt fuel.

[sffans]

So your saying the maf needs to be plugged in and i must have anthor problem other than that?

[sffans]

Hey I just got the car running and it runs great. It was a bad maf and the shop had the timing belt put on wrong. Just fixed it all myself. Bought the car for 1000 and the kid did not know what was wrong with it. He paid 1300 to have new water pump,radiator, timing belt and some misc. done.Put 60.00 into it and now have a nice car. Thanks everybody for the help.