2005 V6 Mustang Starts, Runs 2-3 Seconds, Then Dies

[juba]

The car just died while driving. I initially suspected a broken fuel pump because it just stalled out.

The fuel pump pressure has been tested. The error code pointed to a throttle body issue. I replaced the throttle body, but the problem persists.

It was also suggested that a bad alternator could trigger that error code. The alternator was indeed faulty and has been replaced, but the problem remains.

I thought maybe the injectors are getting too much fuel, so I replaced the Fuel Rail Pressure Sensor (FRPS), but it didn't help. The fuel filter has also been replaced with no effect.

The PATS (theft light) is working normally: it illuminates for 3 seconds and then turns off.

Currently, the car isn't throwing any error codes. It starts, runs for 2–3 seconds, and then dies. After several start attempts, there's a strong smell of gasoline.

I'm honestly running out of ideas and I don't know where to look next. Does anyone have any suggestions on what else could be causing this? Any help would be greatly appreciated!

 

[juba]

Small update: MAF tested, no effect

 

[86GT351]

Lets start from the beginning. What Trouble codes do you have?

 

[juba]

Lets start from the beginning. What Trouble codes do you have?

The codes were P0340 and P0344. After replacing the throttle body, the codes haven't come back and it hasn't thrown any codes since then.

 

[tomkat22]

Those codes point to a problem with the camshaft sensor. I've always heard a bad CPS will make an engine run rough but not shut it down completely. Now a bad crankshaft position sensor will shut down an engine dead in it's tracks.

 

[juba]

We took out the crankshaft position sensor earlier also, and tested it with a multimeter, and it did show some readings

 

[tomkat22]

If you hook up a scan tool (even a cheap one) to the OBD connector,go to the live data's RPM reading,crank the engine and if it shows 100-500 RPMs then the PCM is getting a signal from the CKP and you should look elsewhere to solve your problem.

 

[RGLL]

When my 2006 V6 was randomly stalling, it turned out to be the crankshaft position sensor wiring harness chafing on the metal PCM mount bracket, and it was just the shield braided wire that was touching when I would make a hard left turn. At first I couldn't believe that the shield wire would cause an interruption in the signal but multiple google searches said it could, so I rerouted the CKP harness which was about 8 feet long as it went through the main wiring harness, I used new shielding tape and went directly from the CKP sensor to the radiator mount grounding points and no more random stalling. So check your wiring harness thourghly for chafed areas. I found mine as I was putting the PCM back in after spending $450 to have it and the instrument cluster bench tested.

 

[juba]

Thank you all who have commented, every information is needed, this is so "mystical"

I just get a better "tester" to show what is actually happening.... there's few observations:

• Fuel Pressure: Stays 260–300 kPa while running. Spikes to 436 kPa the exact moment the engine dies. To me, this suggests the PCM is cutting the injectors while the pump is still pushing.
• Sync: CMP/CKP Sync stays "YES" while running. It only drops to "NO" after the RPM hits zero. So, I'm ruling out bad crank/cam sensors for now.
• Codes: Getting B1557 (Ignition Run/Start Circuit) and U1900.
• PATS: Theft light is NOT flashing rapidly.

Alternator was bypassed during this test to rule out AC ripple.

Any ideas?

 

[juba]

If you hook up a scan tool (even a cheap one) to the OBD connector,go to the live data's RPM reading,crank the engine and if it shows 100-500 RPMs then the PCM is getting a signal from the CKP and you should look elsewhere to solve your problem.

When the car starts, the rpm goes to near 800 (pic 1, engine is running), for some reason fuel pump is going 75 %, but it happens after the engine stops (pic 2), just wondering why so.