Frustrated with Explorer!

[jodimarie]

My Explorer starts and idles fine, but stalls when I put it in gear and start moving.
I need some help!
I have replaced the fuel pump, fuel filter, fuel pump relay, regulator and bought an obd1 tester and it gave me a 543 code ( fuel pump secondary circuit fault ) I need to know what this means, and what I should be looking at to fix this problem. I would appreciate any advice offered!
Thank you!
Jodi n AZ

 

[Iron Weasel]

DTC 543
Fuel pump secondary circuit failure.

Diagnostic Trouble Code (DTC) 543 indicates a fuel pump secondary circuit failure between the B(+) supply and the Fuel Pump Monitor (FPM) connection to the power-to-pump circuit.

However, due to the internal circuitry of the Powertrain Control Module (PCM) , a left/front Heated Oxygen Sensor (HO2S) signal short to power could produce a Diagnostic Trouble Code (DTC) 542 or 543.

I don't think an O2 sensor would cause it to stall when put in gear. If there were a problem with the fuel system, then chances are it wouldn't even start, much less idle. I think you're reading an old code that was stored at some point. Clear it out, then start it back up and let it idle for a bit and then recheck the codes and see if you have any come back.

Generally speaking though, if it's an automatic and will run in Park and / or Neutral, but stalls when put in gear, it's because the torque converter is locked which means you're pretty much in the highest gear all the time and it causes the engine to stall out almost immediately when it's put into a drive gear.

 

[TOMANDPAT]

The morons at the quick change oil place replaced my air filter and left the air tube clamp loose at the throttle body. I started it and pulled out, but when I went to pull into traffic, it died. It started and idled fine, I put it back in gear and it died. I popped the hood, saw the loose clamp, had them come out and tighten it back up, and I pulled away, never to return again. Check the simple stuff, it might save you some money and aggravation
Tom

 

[jodimarie]

Thx guys, but a mechanic worked on it for 4 hours and STILL cant figure it out....