TyyB

04 f150 5.4L. Truck drove fine all day and parked it. Started it back up and noticed it idling rough and shaking, step on the gas and it seems to have half power. Finally it spit out codes for Mass airflow sensor, misfire, and cam positioning sensor. I replace the cam sensor cleaned the MAS. Still ran rough. The wires on the mass airflow wiring harness were kind of chewed so we moved the wires around and it started to run normal and rev fine, codes cleared and no more issues. Revd it again and check engine started blinking and it spit out 8 more codes. Mass airflow. Timing over retarder, P0012, Misfire in cylinders and a few others.

Truck runs fine for a while after messing with the wire harness and then goes back to running junky again. Who ever owned the truck before me had electrical tape over all the wires and 2 wires were just twisted together like after they were cut or something. Could the wires be the issue? I made the wires have a somewhat clean connection and same thing happens. It'll ruun fine and then start idling rough. Any help would be great thanks.

TyyB

Just an update. Pulled my codes again this morning and now its reading
P0010
P0020
P0135
P0155
Po443
P0446

Tommy J

I would be suspicious of the MAF wires if you can get it to stop by messing with them. How did you fix them? It almost seems like a bad coil on plug but that may be the symptom of the bad mass wires. See if you can get them secure enough to at least rule them out

TyyB

So ruled out the MAF wires as we have them stable and not moving around. Next guess is possible ECU is bad?

Michael Johanson

Okay, so runs fine when cold, and when warmed at runs like crap?
Mike

TyyB

Replace a burned fuse! All codes cleared and now it idles fine... however it feels like its running only on half an engine and wont rev past 5k RPM. No check engine light but it did throw the code P0012 without the engine light on.

TyyB

Replaced my VCT solenoid on bank 1. Got rid of the tick over there and fixed my issue. Truck runs great now.