BobLoblaw

I've googled all over and a few people have asked about this issue but no answer. I live in Maine so most days are cool, any days over 85F ambient the car will start fine and idle where it should, after 15-20 mins idle will be 1500 in drive and 2500 or more in neutral. Some times so high I cant put in gear, where I have to turnoff engine, get out and push on cruise control cable sheave which will close throttle body control rod. Starts fine and then goes high again. Bought one of those "burping" funnels to make sure no air in coolant system. Temp indicator comes up and goes to its usual position. Runs like a champ except for this single issue.

Opened and inspected throttle body and it was clean on both sides. Valve freely moves.

I've read it might be fast idle thermo valve or idle air control valve, but symptoms don't match my experience. No surging or check engine lights. Check for vacuum leaks with spray carb cleaner but nothing found. I was thinking there might be an ambient air temp sensor somewhere that provides an input but don't see any on intake ducting- that makes most sense to me, as coolant temp should stay relatively constant with thermostat.

It is old and odometer stopped about 10 years ago with 220K on it and I use it as a daily driver. My wife has been bugging me to get rid of it for years, but I like the car more than her.

angrysmileyface

Have you checked to see if the cruise cable is binding? I had a problem where the cruise cable was causing the car to rev up and down only after driving. Disconnecting it alleviated my problem. Also as for your stuck idk, try snapping the trip reset a few times while shoving a key in the main reminder slot. I've discovered on my 95, it's the main reminder function that hangs up the odo

BobLoblaw

Thanks for reply. Are you thinking cruise cable from pedal or actuator to throttle body- that one looks easy but isnt because I can figure out how to remove cable for intake air valve shaft sheave. Cable has a swaged on "ball" that moves with accelerator cable.

As far as odometer it was hard bound on trips ending in 999 & 1/2 and reset wouldn't give me the extra to get to zero. Every once in a while a good bump like sped bump would get in going again, but so long ago bot reaaly a concern these days

BobLoblaw

In case anyone is googling same symptoms I can say for me it was disconnecting the cruise control cable. Over a 100 today and idle rock solid. It took me a minute to figure out how to get cable out of the throttle body sheave. Couldn't see it without mirror and lite but there is a slot the cable fits thorough. Thanks angrysmileyface, saved alot of trouble shooting and parts changing. Don't know why cable binds up at certain temps, could probably get into coefficients of expansion and stuff, but simply don't care. Cable off in 5 minutes and car good for another 20 years.