MasterofDisaster
Senior Member
My car is one of the newer 08s. Few weeks ago, my 3V was running rough. Changed the plugs, and it ran better, but still rough. CEL came on, AutoZone said it was P0303 misfire #3 and gave me a list of coil on plug prices. Like a dummy, I replaced the coils, it made no difference, and the CEL illuminated again.
I could hear the injectors were working, so I was out of ideas. A local shop said they traced it to a bad injector driver for #3 in the ECM. It took about two weeks to get a remanufactured ECM.
Finally the car was ready around 2:30 pm on Friday. I fired the car up and it seemed a little rough, as though it had a cam in it. I passed it off as maybe the computer needed to relearn something, and I drove about five miles before CEL came on again. Went back to the shop. The tech ran some diagnostics and said it was a coil. He installed a new one, but then there was a fouled plug which he replaced. I finally had the car fixed at 5:15 on Friday.
As I drove home it just didn't seem completely right. Today I followed the idle relearn procedure, and the car runs like new.
Owners manual says
This afternoon I checked the OE coils that I had replaced for no reason. The primary circuit resistance on all 8 coils was .7ohms. The secondary resistance ranged from 5.27 to 5.38ohms.
The local Ford dealer told me that my car could use
8r3a12a650 - PB
8r3a12a650 - RB
8r3a12a650 - VB
8r3a12a650 - ZA
9r3a12a650 - MB
9r3a12a650 - NB
9r3a12a650 - VA
I could hear the injectors were working, so I was out of ideas. A local shop said they traced it to a bad injector driver for #3 in the ECM. It took about two weeks to get a remanufactured ECM.
Finally the car was ready around 2:30 pm on Friday. I fired the car up and it seemed a little rough, as though it had a cam in it. I passed it off as maybe the computer needed to relearn something, and I drove about five miles before CEL came on again. Went back to the shop. The tech ran some diagnostics and said it was a coil. He installed a new one, but then there was a fouled plug which he replaced. I finally had the car fixed at 5:15 on Friday.
As I drove home it just didn't seem completely right. Today I followed the idle relearn procedure, and the car runs like new.
Owners manual says
Because your vehicle’s engine is electronically controlled by a computer,
some control conditions are maintained by power from the battery. When
the battery is disconnected or a new battery is installed, the engine must
relearn its idle and fuel trim strategy for optimum driveability and
performance. To begin this process:
1. With the vehicle at a complete stop, set the parking brake.
2. Put the gearshift in P (Park) (automatic transmission) or the neutral
position (manual transmission), turn off all accessories and start the
engine.
3. Run the engine until it reaches normal operating temperature.
4. Allow the engine to idle for at least one minute.
5. Turn the A/C on and allow the engine to idle for at least one minute.
6. Drive the vehicle to complete the relearning process.
• The vehicle may need to be driven 10 miles (16 km) or more to
relearn the idle and fuel trim strategy.
• If you do not allow the engine to relearn its idle trim, the idle
quality of your vehicle may be adversely affected until the idle
trim is eventually relearned.
some control conditions are maintained by power from the battery. When
the battery is disconnected or a new battery is installed, the engine must
relearn its idle and fuel trim strategy for optimum driveability and
performance. To begin this process:
1. With the vehicle at a complete stop, set the parking brake.
2. Put the gearshift in P (Park) (automatic transmission) or the neutral
position (manual transmission), turn off all accessories and start the
engine.
3. Run the engine until it reaches normal operating temperature.
4. Allow the engine to idle for at least one minute.
5. Turn the A/C on and allow the engine to idle for at least one minute.
6. Drive the vehicle to complete the relearning process.
• The vehicle may need to be driven 10 miles (16 km) or more to
relearn the idle and fuel trim strategy.
• If you do not allow the engine to relearn its idle trim, the idle
quality of your vehicle may be adversely affected until the idle
trim is eventually relearned.
This afternoon I checked the OE coils that I had replaced for no reason. The primary circuit resistance on all 8 coils was .7ohms. The secondary resistance ranged from 5.27 to 5.38ohms.
The local Ford dealer told me that my car could use
8r3a12a650 - PB
8r3a12a650 - RB
8r3a12a650 - VB
8r3a12a650 - ZA
9r3a12a650 - MB
9r3a12a650 - NB
9r3a12a650 - VA
