Idle down issues

ELAWREN

MEMBER
TOYOTA PICKUP

2002 Toyota Tocoma 2.7 99000 miles:
After driving highway speeds (60 to 80mph) 15 miles or more, engine will not idle down for 2 to 4 minutes. Idle speed will hold at approximately 1500 rpm or surge from 1000 to 2000 rpm for two to four cycles then hold at between 1400 to 1800 rpm. I have always changed air filter and cleaned throttle body assembly at 30k miles intervals. This problem started at approximately 55000 miles and I have struggled to find solution ever since. There is no codes when tested and engine check light is OFF. Any thoughts?

4 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Find the idle air control valve and the EGR open it up and clean all its passages. Also test the closed and wide open throttle voltages on the throttle position sensor.

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Friday, October 26th, 2007 AT 3:04 PM

RASMATAZ

MECHANIC
75,992 POSTS

Got your PM-have you check for vacuum leak and the idle up solenoid- also might want to check the fuel pressure. Toyota's has 3 different ways on controlling fuel pressure very sophisticated and complicated system.

Also test the coolant temperature sensor probably locked-up on open loop mode and the computer is getting the wrong signal and dumping fuel at it when not needed. And also the oxygen sensor waiting for it to switch so it can take over the fuel adustment in closed loop.

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Monday, October 29th, 2007 AT 7:32 PM

ELAWREN

MEMBER
2 POSTS

I have checked for vacuum leaks and have found none or anything that could potentially become a leak in the near future. Dealing with suggestions in order: Idle speed sensor, is that the sensor or control device on the idle air valve? Best place to test fuel pressure is. And what pressures should I see? I will check coolant temp sensor. What is the normal ohm reading cold and should decrease to. Hot?

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Tuesday, October 30th, 2007 AT 6:57 AM

RASMATAZ