High Idle?

MARK BASLER

MEMBER
2001 TOYOTA TACOMA
2.7L
4 CYL
4WD
MANUAL
160,000 MILES

The truck listed above idles normally upon starting as the vehicle warms up the idle goes up also. 1,800 RPMs. I have cleaned the throttle body, replaced the MAF, IAC TPS and the PCV valve and the upstream O2 sensor. The trucks RPMs would go up and down and after replacing the O2 sensor that seemed to fix the fluctuating RPMs. It continues to run high. I have disconnected the battery for 24 hours to try and reset the computer and have had it reset at Auto Zone and will get a code that says that it's the MAF sensor. I have tried two other MAFs and neither fixed the problem. I have checked for vacuum leaks with parts cleaner and found nothing. I am out of ideas on how to fix this truck. Please help.

Thank you,

Mark

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

You should check the air intake tube for cracks and vacuum leaks and if okay It sounds like the PCM is bad.

Here are two guide to help us fix the problem:

https://www.2carpros.com/articles/engine-idles-too-high

Use the guide when the engine is cold only:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Here is the PCM location and how to replace it in case you need it. Check out the images (below). Please let us know what happens. I would search google or eBay to find a rebuilt unit which will come preprogrammed.

Image (Click to make bigger)