I have a 97 Blazer 4X4 with a 4.3 The truck had a high idle, and it was hard to stop, also it would take about 3-4 seconds to get the drive gear to engage and I was pulling the codes P0507 and P0131, so i bought a new idle control valve and installed it. When I first started the truck the RPM's reved way but it did come back down to a some what normal idle, when shifting in to drive it went right in and all seemed well, but now the truck is running like crap, here is what it is doing and I'm getting the P0507 and P0131 again.

1. when I first start the truck the idle revs up and comes back down
2. I wait for the idle to come down before shifting in to drive and after I shift in to drive it revs back up and then comes back down
3. While drive at 80kph I can take my foot off the gas and the truck stays running at 80 cause of the high idle.
4. While driving if I put the truck in neutral it revs up, if I give it a quick shot of gas to get the RPM's down they go higher and stay there till i pull over and come to a complete stop.
5. When i come to a stop light or sign the truck is running at a high idle and is hard to stop but after I stop it will come back down after 2-3 seconds.

Was there something i should have done with the ICV when I put it in. What can I do.

 

I find it hard to believe, no one has any ideas on this one.

 

Please do not bump a post unless you have already waited 24 hours. Rules are rules.

What have you found through searching since 9AM this morning?

When you installed the IAC valve, did you clean the throttle body? Specifically the bore that the IAC valve operates in?

Here are the diagnostic sheets for the two codes:
P0131 - HO2S Circuit Low Voltage Bank 1 Sensor 1
P0506/P0507 - Idle Control System RPM Lower/Higher Than Expected

 

sorry if I seem a little impatient but I have a 2500km drive next month for work and if I don't get this money pit working right I loss my income for the year, again sorry but I need this truck running right fast.
I will read through the links you gave me and see that I can figure out and get back to you.

After reading the links that swartlkk post, I have a few more questions.
Before I changed the IAC I was having trouble with the truck chugging, well to make a long story short a friend told me that my cat might be plugged, so I took it off and it was so I hollowed it out and put it back on, now with that said, with what I read in the 2 links, is it possible that my O2 sensor with a hollowed out cat is causing the P0507 code to show up, and can any one tell me witch sensor is " bank 1, sensor1".

 

The presence/absence of the catalytic converter should not impact the idle speed of the engine. Did hollowing out the catalytic converter have an impact on the condition at the time?

B1S1 is the driver side upstream O2 sensor which is located in the y-pipe just below the driver side exhaust manifold. A search for "oxygen+sensor+location" should return a schematic view of the O2 sensors in your truck which will have 4 total O2 sensors.

Have you thoroughly cleaned the throttle body? How about the EGR valve?

Have you checked over all of the vacuum lines?

If you have access to a scan tool, you can take a look at the IAC sensor counts to see where the PCM thinks the IAC sensor is. If it is at zero, then the IAC is all the way in (or at least the PCM thinks it is).

Please edit your post to keep in compliance with the rules of the forum.

 

I'm not sure what you want me to edit, If you let me know I will.
Thanks for the help.

 

The EGR valve being stuck open doesn't really manifest the same conditions your are experiencing, but it is a fairly quick, easy, and inexpensive check just to be sure.

You will have to look at the live data to see the IAC sensor count.

I will PM you about the 'edit' thing.

 

Here is something else for you to ponder. About 4 months ago I rebuild the tranny, before i rebuild the tranny it sat for about 1 year. Is it possible the problem is coming from when I rebuild the tranny cause of what is happening.

1. While driving if I put the truck in neutral it revs up, if I give it a quick shot of gas to get the RPM's down they go higher and stay there till i pull over and come to a complete stop. If I'm just creaping alone it won't come down I MUST come to a compete stop.

 

I really don't see how the transmission would cause those symptoms.

Have you checked to see if the throttle is sticking?