High idle (1300 to 1500 RPM) 96 B4000

[speedbump]

Hello, I used the forum to fix the inconsistant idle I had with my truck. I bought the truck at a lien sale so I don't know the history except that it was very cheap The truck itself is in decent shape and is a good project for me to tinker on.

At first, the idle would go between 400 and 1500 RPMs. Once in gear the idle would go to the 1500 RPM range and the damn thing wanted to go... NOW!

Using another thread here as a reference, I replaced the IAC valve. Now the idle is consistently at 1300 to 1500 RPMs no matter what I do. I was getting an error code for the ECT sensor so I replaced that hoping the problem was cured, but nope. I just got done replacing the spark plugs and wireset too. This was to cure a cylinder misfire, but was hoping it might do something too... not so much.

I know I can't manually adjust the idle, but is there anything else that someone can recommend. Thank you.

 

[speedbump]

Bump.

 

[akoutdoors]

If Donnie Strickland cant diagnose it, sell it for parts!

 

[schlutzer]

check your vaccum hoses. mine for the brake booster was cracked and caused the high idle for whatever reason $2 later all fixed

 

[Beanmachine7000]

check your vaccum hoses. mine for the brake booster was cracked and caused the high idle for whatever reason $2 later all fixed

+1... Sounds like a massive vacuum leak...