Stratus - No-Start/Starts-Then-Stalls Diagnosis 🔎

Got it: starts only with throttle, then dies. After cam/crank sensors, fuel pump, and starter were replaced, we’ll zero in on what the PCM needs to keep the engine running: correct cam/crank sync, adequate fuel pressure, stable idle air control, and no theft/ASD cutout.

Quick questions (just two) ❓

• 🧰 Do you have any current check-engine light codes (even pending)? If yes, list the codes.
• 🛠️ When it dies, does the red “security” light flash, or does the light stay off?

High-probability causes on your Stratus 🎯

• 🧩 Cam/Crank sync or sensor type issue — These engines need correct sensor type and air gap. Aftermarket sensors often cause start-then-die. Wrong spacer/shim or tone wheel damage can cause sync loss after a few seconds.
• ⛽ Fuel pressure low or bleeding off — New pump doesn’t guarantee pressure. The 2.4L needs about 49 psi (regulator in-tank). A pinched line, weak pump, or bad fuel filter/regulator module can cause stall.
• 🌬️ Idle Air Control (IAC) stuck shut — If it only runs with the pedal, the IAC may be stuck or the throttle body is carboned up. IAC = a small valve that controls idle airflow.
• 🔌 Automatic Shutdown (ASD) relay drop — If the PCM loses a valid cam/crank signal, it cuts injector/coil power via the ASD. Relay or wiring faults mimic this.
• 🔒 SKIS (factory immobilizer) event — If equipped, a key/security fault can allow a brief start then stall. Watch the security light.
• 💨 Large vacuum leak — Split PCV hose or brake booster hose can cause immediate stall without throttle.

Targeted checks you can do now ✅

• 🧪 Fuel pressure test: At the rail Schrader valve, key-on/engine-crank. You want ~49 psi steady. If much lower or it drops to 0 fast after stall, suspect pump module/filter-regulator or a leaking injector. A fuel pressure gauge is a tool that screws onto the rail valve.
• 🔦 IAC and throttle body: Unplug the IAC at the throttle body, inspect connector pins; remove IAC and clean its pintle and the throttle bore with throttle-body cleaner. Reinstall with a new gasket if torn. A stuck IAC will cause “runs only with pedal.”
• 📏 Cam/Crank sensor specifics:
  • Use OEM (Mopar) or NTK/Delphi. Many aftermarket sensors on this engine cause stalls.
  • Inspect cam sensor spacer/paper gasket—this sets air gap. Missing/extra thickness changes signal.
  • Check the crank sensor O-ring seating; if not fully seated, the air gap is wrong.
  • Inspect the crank sensor harness near the exhaust/axle for rub-through. A short opens when the engine moves.
• 🧰 ASD relay test: In the PDC (under-hood fuse/relay box), swap the ASD relay with another identical relay (like A/C clutch) for a quick check. If it now runs, replace the ASD relay.
• 🔍 Vacuum leak sweep: With it briefly running, listen for a loud hiss. Check the big hose from the intake to the brake booster, and the PCV hose at the rear of the valve cover. Pinch a suspect hose—if idle improves, that hose leaks.
• 🧠 Scan live data (simple checks):
  • Look for Engine RPM while cranking (should read ~200–300 RPM). If zero, crank sensor/signal issue.
  • Check Short/Long Term Fuel Trim at idle (if it will idle). Massive positive trims = vacuum leak/low pressure.
  • Watch TPS percentage at rest (should be ~0–2%). If it reads high, the PCM may not control idle.

If you want me to guide the next step 🧭

• 🛑 Safety: Work in a ventilated area, chock wheels, and keep sparks away from fuel.
• Reply with your codes and whether the security light flashes. I’ll give you exact next steps (including which wire pins to test) for your Stratus.