89 Dodge ram

Im not sure on what is going on im new to working on mopar motors......the truck will run but it wont idle unless your foot is on the gas!! any ideas???

Coronet 500

Is your's TBI, Throttle Body Injection system? These things help with an answer. It sort of looks like a carb on a low manifold.

89 Dodge ram

not sure if it is or isnt but im pretty sure it is!

89 Dodge ram

if is TBI whats a solution to fixing it and if its carborated whats a solution to fixing it? trying to figure out a solution for either or cause im not sure what it has at the moment!

Coronet 500

Not simple but here we go. There is an Idle Speed Controller actuator (ISC) that receives 2-6 Volts from the Single Board Engine Controller (SBEC). This "motor" actuator will click and move as the key is turned to the ON position. It moves in and out adjusting throttle blade position (engine speed) as load changes due to A/C on Power Steering etc. or if the engine is cold. If you disconnect the electrical connector while idleing, engine speed should change (when idleing properly).
My guess is the actuator is stuck in the retracted (powered on) position. Don't try and compensate by turning screw out, if it becomes unstuck your engine speed will go very high. The procedure for adjustment is to disconnect coolant temp sensor and ISC connector and set speed to about 2800 rpm then when reconnected should retract to normal idle and modulate as engine load and conditions vary. Good Luck.

78D200

What work have you done to the motor recently? Has it been sitting for a while or used everyday? Have you adjusted/changed anything? Could be a vacuum leak with either TBI or a carb. Being an 89, I would be willing to be it is TBI but you will need to check and make sure.

Chrystal Ann Saabye

i have issue replased throttle positioning sensor fuel regulator fuel pump, filter and cleaned computer plugs truck still fires right up idles for a few seconds then idle drops n truck dies all plug wires n timongs right just wont idle will if i lightly press gas pedal

Iowan

I don't know if it has a idle air valve but if it does sounds like it's not working properly.

xaza

I just went through this issue on my 360 after replacing spark plug wires. Found a crack in vacuum line at throttle body. I would start with the most simple task and check all vacuum lines and repair any leaks.

RacerHog

Also perform a check of the Idle speed motor if so equipped...