So I just had the 2.3 in my '88 rebuilt after sitting for about a decade with broken piston rings, and it seems like the guy I paid to take care of that headache for me did a pretty awful job. So here's what happens - on a cold start, the engine (usually) fires right up, and idles great. But, if you leave it for a few minutes, the RPM starts bouncing and eventually it'll die. It also will die almost everytime you press the brake pedal, regardless of how well it was running beforehand. If I'm lucky enough to be able to get it up to speed, once it hits about 45-50 MPH, it's like it has nothing left to give - it takes keeping my foot to the floor in 4th at about 2800 RPM to achieve that speed, and it won't go any faster than that. It's been a long time since I had this truck on the road, and I know it's a pretty gutless engine but I don't recall it being THAT slow. I've done my best to check for vacuum leaks, and cleaned out the IAC valve but found nothing wrong with either and I don't know where to go from here. I'm really hoping to be able to solve this problem myself because I've already spent about $8k putting this thing back together between buying parts I needed and tools I needed, plus having the engine and trans rebuilt so I'm a little short on cash right now.