2.7 IAC air supply

2000 2.7 5 speed. Engine has about 3000 miles on rebuild by previous owner. Since I bought it a few months ago, whenever I’ve started it after sitting for about 4 hours I’ve had to feather the throttle and hold it for a few minutes or it would die. Warm idle was around 1k rpm.

Decided to take off the throttle body and IAC and give them a good cleaning but when I pulled them I found a random hose underneath that was plugged. It was the IAC air hose that plugs into the air intake which was also plugged. Cleaned it all and put back together with the air hose back on the air intake (K&N if that matters) like it’s supposed to be. I had the battery disconnect during all of this.

I start it back up and the rpm goes straight to 2500. I let it run for awhile hoping it would settle out but it went on for minutes and I shut it off. I tried starting it a few more times with the same result. Couple rev shots and putting it in gear and it never came back down.

I disconnected the air hose and plugged it like it was when I found it. It did come down in idle but it’s still around 1200 rpm when warm. I can’t find any vacuum leaks and I tested the IAC with a multimeter when it was off the truck and it was in spec.

Being that the rpm shot up when the air hose was hooked up does that mean the IAC is no good even though it tested fine?

 

Try cleaning the maf sensor......

on the cold air injection.....people should take a class on how to clean and re-oil em...youtube..

about half use way too much oil on that.......too much oil equals coated maf sensor....
on my 2.4 your only supposed to use 1 and half oz.....and let it spread out uniformly over nite before you install it...

its easy to hook power leads to iac and test whether that vane is opening and closing correctly......bunch of vids out on how to do that...


If none of the simple stuff works.....maybe take some pics all around the intake, TB, and air intake tube, let others see if they see anything weird or connected wrong...

 

I cleaned the filter but did not oil it. I also cleaned the MAF. It was really dirty but I got it real cleaned up.

 

And then next step would be watch live data with a scan tool...
and look watch going on inside engine from the different sensors...

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I do have that exact scanner.


I will do some more video watching but it still seems funky that when I hooked up the air hose from the iac I was idling so high.