Idle issues. I think...
 

Hello Blazer forum! I've come to pick your brains. I have an 01 Blazer (4.3) and have had intermittent issues with idling in park, and engine speed in drive, at stop. All the symptoms (dying when stopping or at idle, surging while driving, throttle sticking at high RPM's) pointed to the TPS. I also noticed a misfire which was the cap and rotor. Although I found I need a new distributor. I changed the TPS and it made no difference. The only way it'd run is if I kept my foot on the gas. So to Jimmy rig it for a quick fix, I wrapped a zip tie on the throttle body, so it'd keep the throttle open just a bit. And it worked fine for a couple weeks. Then it started idling at over 2000 RPM's. So I took the zip tie off. And it ran perfectly fine for 3-4 days. Then the low idle/dying started again. So another zip tie went on. Now, its a crap shoot as to what it does. I'll get a high idle, then it runs normal. It'll run normal, then decide to high idle. I do have some slack in the throttle cable, so maybe that's it? But I have no idea where else to look. I didn't think to disconnect the battery when I changed the TPS, so maybe I messed it up?? Any advice is appreciated!! Thank you!

Unplugging the battery or not shouldn't matter. I've unplugged my connectors hundreds of times, never messed one up leaving the battery hot.

Doesn't sound like the classic fuel pressure symptoms, but it's a free, easy check to do, even if to just rule it out.

Fuel pressure is good. The pump is only about a year old so I hoped it was ok. Another thing I forgot to mention was, it has erratic shift points from 1st to 2nd. Sometimes it shifts at 4-5 mph, sometimes it'll wind out to 20-25. Also has an occasion where it won't shift into overdrive, but nothing is constant.