5.0L idle Ghost

[richard444]

Guys i have a 91 5.0l efi Wire Diet set up no air pump. Art at Wire diet left the wire for the EGR valve so i left it on and hooked it up but took off the water hoses. I also
used the stock vapor canister. Now here is the issue, the car starts fine and runs good for a while but after about 15 min or so i will pull up to a stop and the idle is high about 1200 to 1500 rpm and stays there. Now if i shut the car off and restart the idle is back to normal at about 800. It will go for a while and then back up high again untill i shut it off and restart. any body have any suggestions?

[John F]

My car does that about 2 or 3 times a year for the last 8 years. I've never figured it out. I feel it's a randon mixed signal from the many bypassed sensors or a 20 year old A9L computer getting lost.