what should i do

Do any codes come up? Do you have the initial fuel-injection system on there?

no codes come up yes its a feel enj. 6.0 diesel

assume its not a diesel? is it a 5.4 or a 6.8?

question answered nevermind ha. A diesel that wont idle ewww!

is the computer seeing any data from the O2 sensor, TPS, EGR, MAF, MAP, any eyes and ears of the computer?~ a diagnostic check will reveal any inconsistencies in the data stream~

it isn't a Jasper remanufactured, they have a 100,000 mile warranty on there if it is~

Wow I almost cannot help my self here judge. how many diesel engines have oxygen sensors? No throttle plate on a diesel so it has no TPS. you have a long list of things to check my friend. I would be happy to list them but first can I ask who put the motor in?

check for fuel pressure

what is your icp reading? unplug the sensor and see if it will idle

computer is wise and knows the diagnosis, may not be sharing with a check engine light, but stores usable information. So cable throttle is what your telling me there kbro, no tps....well okay then~

No cable either. Diesels dont control how much air comes in it controls fuel. No throttle plate it takes in as much air as it can each time.

Gas pedal has a sensor on it that what it uses to add or subtract fuel