Just purchased this truck with "mechanical problems". Truck will not start without Either... and when it does start it has a miss at idle! Revs in neutral were sticking around 2k but are not now.

Truck is 2005 Auto with 200k miles. Heres what weve done so far...

Replaced Batteries
Replaced Fuel Filter
Drained Fuel tank and added 1/2 tank fresh fuel
Replaced Air filter

Codes are...
P0251
&
P2509

Fuel pump seems to be working fine.

Any Ideas???

 

Check wiring harness behind ac compressor, several have been found to be rubbing bare spots and causing erratic conditions. Hope this helps you out.

 

P2509 Power down data loss error (bad batterys or connections)

P0251-CP3 PUMP REGULATOR CONTROL (Fuel control actuator)


Ignition on, engine not running.
Disconnect the Fuel Control Actuator (FCA) harness connector.
Connect an incandescent test light across the Fuel Control Actuator driver circuit and the Fuel Control Actuator return circuit at the fuel control actuator harness connector.
Observe the test light.
The ECM will perform a self test of the circuit which should momentarily flash the test light brightly, one time, approximately 20 seconds after being connected.

NOTE: Check connectors - Clean/repair as necessary.



NOTE: Compare test light brightness to that of a direct connection to the battery.



Did the light flash brightly?

Yes
Replace the Fuel Control actuator

 

OK we changed the FCA and pressure relief valve with no change in symptoms. Found the problem was #4 injector was not firing and 2 others are cracked causing the miss! Replaced #4 with a new one and truck starts with the key but still has a miss to it. We'll be replacing them all very soon.

Thanks to all that responded...

Josh