I'm using my buddies sn here
I have an 86 2-10 truck, it's a 2.8 tbi, now it starts up fine, sometimes i give a bit of gas and it responds fine, then other time it will kind of missfire, buck. Mostly it has problems when i'm at like 1/4 throttle and when decelerate, it is really hard to brake, like i'm losing vacume, engine doesn't sound too good either, then after a few seconds idling it calms down and i have regular brake pedal feel. I've just done all the brakes, fuel filter, plugs, igniton wires, pulled back the timming a little ( the proper way with the wire pulled) and tightened up and richneded a little the tps sensor which was loose, water temp sensor the basics. I haven't found any vacume leaks haven't look too too hard, it idles fine, this is a recently rebuilt enine from the guy i bought.

I think it is fuel pump or egr valve/ solenoid, it does tend to get a little hot, but i know the rad is ****ty and replacing that, what does it sound like to you guys???