By any chance, when you removed the IAC the first time, or any other time for that matter, did the oring stay on the IAC or did one of them get lost in the TB IAC bore?. And are you sure you cleaned the bore out real good.

And btw, I would NOT have adjusted it. It will adjust itself in time.

 

O ring is still in the old IAC. I removed the throtle body for clean out.
Test drive right now: Drove a couple of miles, kick in full. Same problem. RPMs increase to 1350 as per scan tool at the time of fail (freeze data)
MAP 48 KPA
coolant temp 192 degrees

When I arrived home, 10 minutes ago, it was around 1500 RPM at idle. I removed the negative battery wire and turn on the lights to reset the PCM. Wait 5 minutes and start engine again. 600 RPM !!!!!!!!! That means it doesn't matter with temp, vacuum leak or O2 sensors????? Could be the PCM itself reading false values and keeping on it???

 

Any help??

 

Back probe or check the volts of the TPS with the scan tool when it's at 600 and again when its at 1500. Should be the same if TPS is not involved in this problem. Then I'd go back and do everything that has been suggested earlier in the thread by various people.

 

I will do that ASAP ( when comeback from work) and I will let you know. Thank's

 

nobody wanted to comment on this? it's pulling a massive amount of fuel.

 

I don't think that scanner he has is telling the truth,

 

TPS voltage at idle 600RPM : 0.68 V
TPS voltage at idle 1500 RPM :0.68 V

Looks like it is not the TPS. This is a linear potenciometer. I tested before its resistance while the throtle is moving and was OK, but now we know that nothing (temp ie) is affecting the TPS reading.

No plenum leak!!! Did the test and I have pression in the vacuum gauge. Not vacuum.

Noticed again if I drive smooth, even above 2000 RPM, nothing happen, everything is normal. If I kick the truck, in a couple of block, it is high RPM again at idle. I will disconect the O2 sensors now and test again.
btw, is there any way to trace the wires from the O2 sensor to the PCM? I mean, do we know wich connector and wich number belongs to the O2 input at PCM?

 

A Haynes or the FSM download in the FAQ section will give you that info.

 

Disconected both O2 sensors. Test drive. Took more time to get in trouble but at the end, trouble appears again. When I stop the truck, RPM decreases faster than before. They recovered to 600 RPM in less than 2 minutes. Somebody has any idea?