Got a weird issue. Truck runs fine. But lately, when im idling i cant touch the gas and hold it under 1900 rpms. It instantly jumps up to 1900. Only works when im in drive or reverse then i can hold it at 700, 800, 900, etc.. any ideas? Im thinking throttle cable or something like that. I have a new iac on it, since i had a problem with it dieing randomly at idle.

 

what year, engine, mods ?

 

Thought i had all that in a caption thingy at the bottom. Its a 99 laramie 4wd with the 46re. And 5.9l gas.

 

And only mods are i beleive its a 3 inch intake. And dual exhaust.

 

Possibly throttle position sensor.

 

Rite on. Ill test her out and see if i cant find anything. Thats the only sensor i could thing itd be as well. Ive replaced most just not that one. Thanks peps!

 

I tested the old tps.
Idle- .33v
WOT-1.97
i also have a hughes intake with throttle body. I looked through there manual last night, since i also have a whistling after heavy throttle. The truck also does not have a warm up mode. If i start it cold in the morning it shoots up high then almost instantly drops to idle. Thats when i try to hold the idle at 1000 or so in cold weather to warm up faster but it wont let me, instead it goes to 2000rpms.

 

TPS readings are wrong. There is a problem there. Low value is good, high value is not.

 

Maybe i tested the wrong wires. Manual isnt to helpful since it only says the middle wire is the feed to the pcm and everything else refers to using the DRB. So i probed the middle wire and the left wire as ground, towards the front. That was my reading on the 9v scale i used for my voltmeter. I replaced the sensor and still nothing.

 

Also when i bought the new tps the old one i had that came on the truck was adjustable, drilled out. And i took off that adjuster for the iac PO had hooked up.