S-10 Forum banner

86 2.8l really high idle

4K views 13 replies 3 participants last post by  jimmykicker 
#1 · (Edited)
Not sure if I should post here or the 1st gen forum but:

1986 2.8l 2wd blazer. When running it's like you foots on the gas. When driving it'll take off on it's own. To the point where I can get up to 60 and never touch the gas pedal. Replaced IAC and TPS. Rebuilding throttle body today, needed it more than the current issue but figured I'd throw that out there to. No vac leak, that I can find. Maybe I'm just missing it idk. No CEL. Throttle cable dosent seem to be hanging up. Any ideas what I could be missing?

TL/DR:
ended up being egr related.
 
#2 ·
Spray around the throttle body and the intake with either water or carb cleaner. If water and it finds a vacuum leak, the engine will cut out. If you use carb cleaner, it will kick up. Some people freak out about the water, but I've done that trick for decades. Doesn't hurt a damn thing.
 
#6 ·
Checked your timing to make sure your distributor hasn't slipped?
 
#8 ·
Update: blocked off egr hole and plugged vac line and it calmed down to normal, while in park. Still high rpm while in any other gear or neutral. Nothing to the extent it was though. Gonna replace egr next week and see if that helps. Hard to believe a bad egr causing all this, but....idk. I'm not a mechanic. Also haven't checked timing like mentioned before either. Idk how.
 
#9 ·
Thanks for the update. Let us know how you resolve it.
 
#11 ·
Update 2:
New egr installed. It came with a bunch of washers to go in one of the holes. Wish I'd have gotten a pic. Anyway, I knew when I went to install the washer fell out. So instead of trying to find the one that was supposed to be there I just grabbed the next closest size(smaller hole) and used that instead.

Anyway, there's been a whine/whistle ever since, on top of the high idle issue. I assumed it was the hole in the washer being too small. So, I fished the one that was supposed to be installed it from the depths of the top of the motor, close to the firewall. Removed egr and not only did I have the washer thing going on the gasket slipped on one side so it wasn't sealed good and was blocking the rectangular port on the edge valve. Installed correct washer, took my time to make sure gasket was where it was supposed to be, and..... Problem solved.

Normal idle in park. Normal idle while driving. Now it's tune up time cause she's skipping something serious 😂 if it ain't one thing it's another, I guess.

Thanks for y'all's help/input.
 
#12 ·
Excellent! Thanks for the follow up man. So often these things get fixed and they're left open-ended. Good info!
 
#14 ·
This community has helped me so much over the last 16 years I even became a lifetime member.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top