1UZ-FE with Rough Idle, mm the IAC?

The 1UZFE EGR Delete Kit is available for sale here.

Zorlac

New Member
Messages
4
Location
Santiago, Chile
Hello everyone
I always read the forum and helped me a lot in the project finished a while ago a toyota hilux with 1UZ-fe motor (a 1992 SC400) coupled to a 4x4 R150F.

At first it has gone great, nothing to say the engine is great, I have only one drawback which unfortunately has now become more often

"sometimes" when I starting the engine cold, the engine starts to idle a little more rapid than normal, then in use as the vehicle warms up more and the temperature rises in the idle stops at traffic lights , etc.

the beginning I thought it was normal, then I remembered the self-diagnosis, because
Since you make the conversion, the CEL is on 90% of the time
so using the OBD1, it throws the following codes:
21, 27 and 29,
According to the table
Main O2S & Heater Signal, Sub O2S Signal and Sub O2S,
My project doesn't have CATs., just a 2.5' Y Pipe with a Magnaflow muffler.


The strange is that this engine was bringing just 2 O2S, I assume they were the primary, for sure replace both issue a new pair (Denso), immediately noticed a slight improvement, but both the CEL remained on and sometimes again what happen accelerated idling.

A few days ago reading about this, saw others out there that it has happened that the OBD1 code does not throw when failure comes from the Idle Speed ​​Control, Idle Air Control or Valve,then one day already came with the failure, do the process of removing the piece, clean (was kinda dirty) and voila I starting the engine and departed as never before had left, very soft quiet.

They spent 4 days the engine to behave in Wonderland, and now has returned to the initial symptom, since I turn it on in the morning begins slowly climbing the rpm, the idle is high (no rocks, only the minimum is high )

'll do again tomorrow cleaning the IACV, to "check" that's the fault, if I prove again that you think could give the matter closed and buy a IACV for this engine?

The major obstacle is that I have reviewed and new valve that is very expensive compared to other products for this engine, and is apparently only for this engine it uses, the vvti is not the same.

Stay tuned to see your wise experience and I suguieren before screwing

Greetings !!
 
Sub O2 sensor DTCs would not affect idle speed.

While 21 is a primary O2 sensor, and in theory, it may lead to engine playing tricks. Try disconnecting both primaries, and discnnecting the battery for a couple minutes to reset ECU. Run engine with both primary O2 sensors still disconnected and see if your problem appears again.
 
Sub O2 sensor DTCs would not affect idle speed.

While 21 is a primary O2 sensor, and in theory, it may lead to engine playing tricks. Try disconnecting both primaries, and discnnecting the battery for a couple minutes to reset ECU. Run engine with both primary O2 sensors still disconnected and see if your problem appears again.

Thank you!

It works as you said
, now still have the cel on, but,the engine sound like a cat sleepng :)
Finally,im so happy

regards

:D
 
Glad I could help. Now that you know it's primary o2 sensors playing tricks you may want to replace both primaries with the original ones or at least known good substitutes like denso dox-0109
 


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