the other day going down the highway i noticed that the truck was keeping itself going. like i had the cruise control on. . it was idling at about 1200 goin down the highway with my foot off the gas. when i got to where i was going and left it park and after a couple minutes it died back down to where it should be. Just now on the way to the store and back it was doing the same thing except when i left it in park it didn't die down it just sat there above 2k. Could this be the result of a TPS ( Throttle Position Sensor) going bad?

Could a bad TPS cause a loss of power? You hit the gas but doesn't go anywhere because the sensor is bad it doesn't know where the throttle really is? I noticed that while it was idling high that it would actually shift at about 4k which isn't what its been doing if anyone read my other post titled "Overall Pain".

 

i would have to agree on the TPS.. get yourself a chilton manual or the factory dakota manual off the board, take a multi meter and test it out, remember to use ohms scale

 

the weird thing is, is the check engine light is not on. I have the service manual but i can't find any where that says how to test it

 

look under fuel system, it's there

 

sounds like the TPS. and not every sensor throws a code when they go, they just give false readings

 

Sounds like it could be a vacuum leak as well.

 

I would also suggest vacuum leak because I removed it to pour sea foam in this cause it to idle higher.

 

just went out again and still with the high idle except this time the engine light came on. Code 1294. Which it says could be three different things or all three. It says idle not reached in gear or something to that matter, vacuum leak, or IAC. Little confused here. lol. If the TPS is making it idle high then it would throw that code because normal idle RPM isn't being reached, correct? But then it could also be those other things as well. What should i be looking at? Why? and how do i test it if at all possible?

 

So, i'm lookin at either the TPS or IAC. i know how to test the TPS, but how would i go about testing the IAC. Also, while i'm driving down the road with my foot off the gas and it idling high it cuts out for a quick second and picks back up. Like, if its idling itself at 1500 going down the road with my foot off the gas it'll die down to about 1200-1300 and then pick back up. It feels like its going to die.

 

Check all of the vacuum lines coming off of the throttle body and intake manifold.