Is the mass air flow sensor dead?

How do i test the idle air control valve, mass air flow sensor & throttle position sensor.?

• i have a 95 maxima. my problem is when i start the car in the morning i have to hold the gas for a few mins. otherwise it turns off. the rpm just drops. When the car warms up its runs great, no idle problems. i went to a mechanic and got a diagnostic test reading IACV, egr valve and knock sensor came up. i did a full tune-up, changed the knock sensor, egr valve & checked for any vacuum leaks. i have an ohmmeter & want to check ths mass air flow sensor, throttle position sensor & idle air control valve. can anyone explain how to use the ohmmeter on the IACV, MAFS & TPS, the connectors on the all 3 sensors have three pins. please explain the steps before i spend more money on repairs.

• Answer:

  You are probably wasting your time and money with this. Fuel injected cars work totally backwards from carburetted cars. The "gas" pedal is really the "air" pedal. If you must add more air to keep the engine running, then you probably only have a dirty idle air control valve. Locate it, remove it, clean it with Gum-out spray. This little gizmo is responsible for a host of invisible idling and running conditions. When it is not running right, it can CAUSE egr trouble, knock sensor trouble, and other hard to find woes. Over time, it can even cause expensive exhaust system trouble, including catalytic converter wear. While you are at it, clean the throttle body and plate. Also, check for the proper operation of your engine temperature switch. There is one that sends a signal to the CPU to tell it what temperature to use for adjusting fuel/air mixture. Use ONLY genuine Nissan parts. While you are at it, clean as many engine sensors that you can find. Check the wiring harness at the MAFS and the TPS. Most of these things will throw a code if they are malfunctioning. The things that most often cause trouble do NOT trigger a response from the OBD II. Good Luck!!When you have cleared things up, install a set of the new ND Twin Tip spark plugs. Your fuel mileage and power will go up. Good Luck!!