Hello,
I'm helping a friend with his 99 F-150 4x4 with the 5.4 motor. The truck lost power on him the other night going up the hill to his house. It will start and idle, but would not have power to go when in gear.

I pulled 7 codes and tried to drive it. It would idle rough for me and it would rev up, but once in gear, it ran poorly and misfired. One code noted misfire on cyl. 4 so i replaced the plug and coil pack. Two of the codes were for the Oxygen sensors so we also replaced them.

Again i started the vehicle and it idled great ( no misfire) and reved up quickly. Once i put it in gear, it klunks in and still has no power. When you give it gas, it acks like it is running on 4 cylinders or like when you are driving a 4 speed and you are lugging it in the wrong gear. I was able to back it up and pull it forward, but no power at all..

I also checked the fuel pressure and it was at 32psi and rose to 38 when reved up.

The tranny codes are:
P1747 Manf.control, Transmission
P0750 Shift solinoid A Malfunction
P0755 Shift solinoid B Malfunction
P0743 Torque Converter Circuit Electrical

Thanks in advance for the help and advise.

Still Parked and Won't Go!!

Joe

 

I'm no expert on the transmission but, with the codes that you have for it and the symptom, I would guess that the transmission is in trouble or shot. Sounds like it is in 3rd gear and can't shift down to 1st or 2nd. Good luck!

 

Check the electrical connection to the trans on the passenger side of the trans. If it is unplugged or has a poor connection it will set those codes and start off in 2nd gear. Both shift solenoids off = 2nd gear.

 

I will have him look at the wires and make sure that he has a good connection at the transmission. The part that confuses me is that the truck will idle good and rev up in park, but it sputters and stumbles once in gear. I know on the older cars you could still take off in second, this thing does not even want to go anywhere.

Would anything from the codes effect computor to make the engine run poor or to make it stall. One other thing, the overdrive light was flashing on the gear selector.

Would any other engine problems cause the tranny to code? I was thinking of checking the commpression to make sure the valves and head gaskets were good. What are the symptoms if the convertor is really plugged up?

 

Check the fuse that supplies power to the transmission electrical system. I forget which one it is, check your owner's manual.

However, if it blows, your exact symptoms will result.