Hi everyone, just looking for some help with a high idle issue with my c2500
 

I hope not to get bashed for not searching but I have searched multiple forums and I'm just curious what others would do. My truck is an 88 c2500 I bought from my grandfather but from what I gather it has an engine out of a 90 chevy truck... it has a high idle condition and I've been having trouble getting it down .. I've checked for vacuum leaks and non exist other then if the intake itself is leaking .. I didn't get a chance to check the egr valve but will tomorrow.. I'm thinking about buying an aldl cable and resetting the thottle adjustment cause I'm not sure if the tbi is original to the engine or ecu... and help or opinions is appreciated.