Mazda MPV start-run intermittent issues


#1

I have a 2000 Mazda MPV that has had the same problem 3 times this past month. First, it won’t start unless I hit the gas pedal (fuel injected, don’t normally have to do this). Then, it won’t hold the idle unless I keep one foot on the gas. Yes, I have to drive with two feet in order to stop. If I stop without keeping my foot on the gas, the engine cuts off. Then I have to start it up again - while giving it gas. After driving it for about 20 minutes, it stops doing this and runs fine. It has done this 3 times this month. Full tank, empty tank, it doesn’t matter.



I took it to the shop the first time this happened. It was running fine by the time I got it there. They ran a computer diagnostic and found nothing. I also put one of those fuel system cleaners in the tank after the first episode.



What is this?


#2

You may have a faulty Idle Air Control valve and/or a dirty throttle body.

When was the fuel filter last changed?


#3

[b]The problem might be with the idle air control circuit.

There’s a component on the throttle body called the Idle Air Control/Air By-Pass motor. What this device does is allow air into the engine anytime the accelerator is released so the engine can idle. If this component sticks or malfunctions, the engine can be hard to start and will stall when the accelerator is released.

When you step on the accelerator when stopped, you slightly open the throttle plate on the throttle body. Doing this allows air to enter the engine so the engine continues to run. So you’re basically substituting the defective IAC/ABP motor with the throttle.

Since you say this problem goes away after 20 minutes of driving, the IAC/ABP motor might be sticking from deposits. And once it heats up works normally.

The first thing to try is have the IAC/ABP motor removed and clean it and the idle air bleed port on the throttle body. Reinstall it, and see if this fixes the problem. If not, then the IAC/ABP motor may require replacement.

Tester[/b]


#4

Tester,

Thanks for the details. I will have that done. You don’t happen to have a shop in Virginia, do you?