Howdy,

I was having surging issues with my ac on and figured it was the iac valve. Swapped it out and that's when the fun began. Idle shot up to between 1500 and 2100. Figured it was a bunk iac valve brand new and put the old one back in. Same situation. It then threw a P0507 code....idle higher than expected. Did some research and one of the possible causes was a vacuum leak. So I busted out my homemade smoke machine and did not find a leak. PCV valve is good. EGR is good. FPR does not have fuel leaking out of the vacuum hose. I pulled the throttle body and cleaned it up (I had done this last year so it wasn't bad) Cleaned the maf sensor...pulled the egr valve and checked that....it appears ok. Not sure where else to go. I think I read o2 sensors may be at fault. I have a nelson tune with the rears turned off. I also have obd link ii to look at o2 voltage and what not. Not sure what I'm looking for there, although the voltage does move around a lot. Any ideas?

 

Did you put the oring/seal on the iac valve, and what are your iac steps at, o2 sensor voltages should swing back and forth between i wanna say .2 and .9 mv on the scanner if you have a vacuum leak or iac is open too far you will probably be staying on the lower end of the scale which iirc is lean..... O2 readings shouldnt affect youre idle though......

 

Yup. O ring is on iac valve. I don't think I can read iac steps with the reader I have. I'll take it to autozone tomorrow and check with their scan tool.

 

They will normally just pull codes, not show data...

 

Guess I need to find a reader that will show iac steps.

 

That or unbolt it pull it out with it connected turn key on abd make sure it moves..... The wires have a tebdency to break inside the connector

 

I'll give that a shot. Thanks.

 

sitting at 193 counts with key on, and down to 70ish with key off. I couldn't see it move however. If I connect a multimeter to the plug what kind of voltage should I be seeing?

 

That is ridiculously high.... Your counts with it running should be about 50-60 or so.... Try reconnecting the iac and disconnecting your tps sensor turning the key on and then turning the key back off and reconnecting the tps

 

Ok, before I read your post, I reinstalled the old iac valve, disconnected the battery for an hour of so and fired it up. iac count went to zero and rpm hovered around 1500. During that time I sprayed maf cleaner around the manifold, egr, etc to see if I could spot a leak. No rise in rpm, so I think I can rule that out. I datalogged it, but I think the file is too large to upload, so i will do another log...shorter this time and see if I can post it.