Hi guys,
I hope you can help me with this one. I have a TOYOTA Prado with a 3.4l 5VZ FE engine. The truck has 100.000 miles on it and about 6 months ago it started reving up quite high during cold starts. Most of the time the CE light would come on with code 33 (IAC).
Since then I replaced the IAC, the CE light doesn’t come on anymore however the idle speed is still high when the engine is cold (about 1800 RPM) and when it's hot (about 1050 RPM).
I have also replaced the cold start temperature sensor, cleaned the MAF, cleaned the TB and checked for vacuum leaks.
The weird thing is that there is a condition where the idle speed is right. That is when the engine gets completely warmed up and I turn it off for a couple of minutes, then when I start it back up again it revs nicely at 750 RPM. If I then start driving it will never come back down to that level.
Another weird thing I noticed (after changing the IAC) is that when the truck is moving while in neutral the idle speed is slightly higher than when the truck comes to a complete stop. It's like the ECU determines that the truck is moving and "orders" a slightly higher idle speed. I did not have this effect with my old IAC valve ……
I am now totally confused since I think I have no place else to look for a "cure". I hope you could advise.
Cheers
I hope you can help me with this one. I have a TOYOTA Prado with a 3.4l 5VZ FE engine. The truck has 100.000 miles on it and about 6 months ago it started reving up quite high during cold starts. Most of the time the CE light would come on with code 33 (IAC).
Since then I replaced the IAC, the CE light doesn’t come on anymore however the idle speed is still high when the engine is cold (about 1800 RPM) and when it's hot (about 1050 RPM).
I have also replaced the cold start temperature sensor, cleaned the MAF, cleaned the TB and checked for vacuum leaks.
The weird thing is that there is a condition where the idle speed is right. That is when the engine gets completely warmed up and I turn it off for a couple of minutes, then when I start it back up again it revs nicely at 750 RPM. If I then start driving it will never come back down to that level.
Another weird thing I noticed (after changing the IAC) is that when the truck is moving while in neutral the idle speed is slightly higher than when the truck comes to a complete stop. It's like the ECU determines that the truck is moving and "orders" a slightly higher idle speed. I did not have this effect with my old IAC valve ……
I am now totally confused since I think I have no place else to look for a "cure". I hope you could advise.
Cheers
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