Next, you'll need to read and record any diagnostic fault codes. Chrysler made doing that yourself much easier than any other manufacturer. Cycle the ignition switch from "off" to "run" three times within five seconds without cranking the engine. Leave it in "run", then watch the code numbers appear in the odometer display. You can go here:
https://www.2carpros.com/trouble_codes/obd2/p0300
to see the definitions, or I can interpret them for you.
If there are no related fault codes, be sure you're pressing the accelerator pedal 1/4" during cranking. If that doesn't help, we're going to need a scanner to view live data. There's three key pieces of information we'll need. First is the "idle steps" the Engine Computer has placed the automatic idle (AIS) speed motor to. Normal is around step 32. If it's at step "0", minimum throttle hasn't been relearned yet.
Next, we need to see the state of the crankshaft position sensor and the camshaft position sensor. On my Chrysler DRB3 scanner, those are both listed as "No" or "Present". Both will be "No" with the ignition switch in the "run" position. They must both switch solidly to "Present" during cranking. Aftermarket scanners will have some similar terminology to show when those signals are being received by the computer. If one stays on "No", that is the circuit that must be diagnosed.
Don't overlook low fuel pressure. A simple squirt test at the test port is not sufficient. It only takes a few pounds of pressure to create a strong spray. As I recall, your truck requires around 45 psi fuel pressure. That should be checked with a fuel pressure gauge.
Let me know what you find.
Tuesday, January 31st, 2023 AT 10:29 PM
