91 F-250 5.8L Throttle issue

[soulfinder09]

To start I am not mechanically inclined however I am trying to learn how to do things on my own. I have some help from my uncle but he lives a couple hours away but will help if I get in over my head...

So when I start my truck it seems to be idling right about 1200 rpms. However if I rev the engine it will not return to the original idle it will stay where i revved up to up to over 2000 rpms. It seems to me like the throttle is getting stuck. Is there a way for me to confirm this?

 

[5.0Flareside]

with the truck not running you can push the throttle and see if it'll return to it's original location..

if it does, then you have a electrical issue.. im thinking TPS.. it's seeing it go above 1 volt and then doesnt realize it kicks back down below 1.0..

below 1 is idle and above is run.

is it idling cold at 1200?? or warm?

if warm at 1200 it's WAY to high..

 

[5.0Flareside]

You also may have a vacuum leak I'm leaning towards electrical..

 

[jbashaw]

mine used to do the same exact thing and i replaced the tps (throttle position sensor) and to change it you have to remove the throttle body so while you got it off give it a good cleaning paying close attention to vacuum ports cause they are so small the plug up easy... I'd almost bet that fix it cause i chased vacuum lines and cleaned the Iac but once i replaced tps and cleaned throttle body it ran like a New one...

 

[SuperCab]

Could be a sticking idle air control too...

Sent from my iPhone using Forum Runner

 

[soulfinder09]

Thanks for the help. I will work on it this weekend and see what happens

 

[soulfinder09]

So it got a chance to get under the engine. It seems the main problem is that the Throttle Cable Bracket and cables and springs are all old and worn out and is not kicking back to the start position. I hope replacing the springs and bracket will get it working correctly.

 

[dustybumpers]

The plastic jacket inside is disintagrating, and the spring is catching on it. I have had this happen twice. I replaced the whole cable with a new one.