gmbellew
Full Access Member
- Joined
- May 27, 2018
- Posts
- 1,286
- Reaction score
- 1,409
- Location
- Kansas city
- First Name
- glen
- Truck Year
- 1990
- Truck Model
- suburban 1500
- Engine Size
- 350
the idle started to hunt on me a couple months ago. I'm only about a year on the most recent tuneup, so I ran some fuel system cleaner to see if that would help. no change. so I finally got curious enough to plug in the ALDL scanner and watch some data. I noticed that at idle, I could see the TPS voltage randomly vary by up to 0.04v without any actual pedal input. the idle would hunt as the TPS voltage would vary. I couldn't find any loose connections and the TPS was not loose. I happened to have an old spare, swapped it out and all seems good after a couple test drives. Just passing this along in case it helps somebody. I guess the ECM thought I was adding throttle, and making adjustments. but since I wasn't actually opening the throttle, it was making adjustments that it didn't need to make.
