Well I completed the head gasket this weekend, went well but had a couple issues that I will discuss in my other post. I didn't end up with any extra parts so I guess it was a success.

However, when I started the truck up it immediately idled up to 2,100 rpm and stayed there. After a short drive and warming it up the idle went down to about 1,200. Then when I went to drive it the RPMs would surge up 800 to 1,000 RPM and then back down and then back up and down and so on. It was spuratic when it was accelerating under load but the idle smooth and steady (although high.) If I drove VERY gingerly it wouldn't do this. It felt almost like the transmission would shift into neutral for a second and the RPMs would rise and then it would kick back in and the RPMs would go down. (I know it is not the transmission because I haven't had any trouble with it, that is just the best way I could describe it.) The check engine light has not come on. My first instinct tells me to check the throttle position sensor first, followed by vacuum leaks. I'm going to double check all of the electrical connectors and vacuum lines. Anything else I am forgetting that might have been disconnected or bumped during the head gasket job? The battery was disconnected for 3 days, any chance the ECM lost it's "memory" and is just trying to re-learn things? I drove it for about 20 min and it didn't seem to improve any. How about the crank sensor? Where is it located on this truck? Is the connector colored? Any ideas would be helpful. I'm just trying to brainstorm before I take a look at it after work.

Don't you just love that the truck will give you engine codes all the time when there is nothing wrong but when you do have a problem it never goes on?

 

Went out a lunch time and disconnected and reconnected all of the wires and hoses that I had to unhook to do the job and it fired up and ran fine. Must have been a loose connection with one of them. Thankfully, Lucas, the Prince of Darkness must have granted me a pass on this one.