Correct me if I am wrong but if the throttle plate is closed, you plug off the IAC motor & it idles down, where is it getting air from? Randy

No I didn't completely cover the hole 80 to 90 percent. Yes plate is closed going to check timing now.

no i think you have found your problem,,if it idles good with 10-20% of the iac valve blocked,,,then what is the reason for having a large air intake at the iac,,,keep looking for a vac leak,,like randy was thinking

I am back thinking vacum also but here is what I did couldn't ck timing (never let your kids in your tool box .....light isn't working now)but got it in service mode no codes other than 12. Pulled then plenum retorqued bolts on intake they were a light looser than I would have liked book says 30lbs they were about 25lbs but still not right also checked iac plug two have power steady but two have nothing and book says all should be blinking power. Vacum is still a little low to be 10 to 15 that motor says 15 to 18 on pressure .
Thinking next think is to pull intake off and put new gasket on. What does everyone think worth the time.

alright manifold is good can not find any vacuum leak.but back to the iac was rereading manual and it says all for wires should be blinking from ecm it is mefi 3 ecm I only have 2 wires that are hot and they are both always on not blinking. could this be a ecm that is bad? just don't want to throw a ecm at it

all new stuff help idle is still high but we were trying to figure out if cover most of iac would idle fine ran great stopped it and now it wont start steady beeping.............when the key goes on have not looked any further yet doesn't sound like I am getting much of anything other than it cranks. it is a mefi3 manual says it should not be steady beeping

alright think the computer is out it has a steady beep when you turn key on and pulling code 51 on ecm. just happy I can stop looking for a vacuam leak lol I have replaced every gasket on intake..
with a code 51 I have read the ecm is just shot but where do I go to get ecm it is a mefi 3 and local deaqler wants 1500 for the computer alone as he said they don't make them any more. what is my best way to go here?