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C. Walker, Jr.
C. Walker, Jr., Auto Mechanic
Category: Ford
Satisfied Customers: 710
Experience:  Shop training and experience.
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My 2004 F150 won't accerrate fast it keeps jerking each time

Customer Question

Hello my 2004 F150 won't accerrate fast it keeps jerking each time I press the acceptor down completely
Submitted: 1 year ago.
Category: Ford
Expert:  C. Walker, Jr. replied 1 year ago.

This can be caused by a few different things. It could be an issue with the throttle body do you have some carb cleaner? We can clean and retest. If not do you have a scan tool to check for codes if not the local auto parts stores will do this free if you can make it there. We need to pinpoint the problem. It could be bad fuel faulty fuel pump or even spark plugs. If we can get the codes it will make it much easier but either way let me know and we will fix it.

Customer: replied 1 year ago.
No code come up
Customer: replied 1 year ago.
Only the blinking theft light
Customer: replied 1 year ago.
I have scanned I still don't get any code
Expert:  C. Walker, Jr. replied 1 year ago.

Check for battery voltage at the fuel injectors on the Red wire at any fuel injector connection with the ignition switch in the Run position. If the circuit does not indicate battery voltage, check fuse 2.34 (20 amp) of the central junction box for a blown, missing, or poorly connected fuse. If fuse 2.34 has no power to it with the ignition switch in the Run position, check fuse 2.28 (5 amp) of the central junction box to verify it shows power with the ignition switch in the run position. Also remove the powertrain control module power relay from its holder in the central junction box and verify two of its terminals show power with the key in the run position. Install a jumper wire between terminal 3 and 5 of the relay to determine if power comes back to fuse 2.34 indicating a defective power relay. If the RD wire of the fuel injector shows full battery voltage, check the Brown/White wire of the fuel rail pressure sensor to verify it shows 5.0 volts with the key in the run position. If the BN/WH wire at the fuel rail pressure sensor shows to be less than 4.9 volts with the key in the run position, disconnect other powertrain control module sensors fed the 5.0 volt signal and look for the voltage on the BN/WH wire to come back to 5.0 volts indicating a shorted sensor. This would include the power steering pressure sensor, the throttle position sensor, and the fuel tank pressure sensor. If the vehicle reference voltage signal is still low with these devices unplugged, verify battery power is present to the powertrain control module on the RD wires at pins 51, 52, and 53 of the C175b (middle) connector. Also check the BN/WH wire for a short to ground in the harness before condemning the powertrain control module.

Customer: replied 1 year ago.
Is possible that the PCM is bad even when the car can move if I accerate gradually
Expert:  C. Walker, Jr. replied 1 year ago.

That is a possibility I dont want to just throw parts at it though. But if you follow the testing you will know for sure if it is the pcm or not.

Customer: replied 1 year ago.
Ok I will check all the fuses
Expert:  C. Walker, Jr. replied 1 year ago.

Excellent I hope it is just a bad connection and not the pcm but either way we will figure it out.

Customer: replied 1 year ago.
Assuming the worst, what happens if it is the PCM that is bad
Expert:  C. Walker, Jr. replied 1 year ago.

If the PCM is bad you need to get a replacement. I recommend getting a used one if possible to save on the cost. New they can run about 800 from the dealership but I know you can go online and get it much cheaper.

Expert:  C. Walker, Jr. replied 1 year ago.

If it is the PCM make sure the replacement matches the numbers. You will not have to program the used replacement if it is the same. Saving you that fee.

Customer: replied 1 year ago.
I will try and get back to you tomorrow
Expert:  C. Walker, Jr. replied 1 year ago.

Perfect!!