Wild Timing Advance and Retard? 2003 5.4L 2V
09-10-2015, 06:03 PM
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Wild Timing Advance and Retard? 2003 5.4L 2V
I've been chasing a problem on my 2003 F150 with the 5.4L 2V engine with 105K miles. It has thrown lead codes on both banks (P0171/0174), misfires on #1 and #7 (P0301/307), shuttering, sputtering, awful MPG, and overall just runs like ****.
I know it's not the MAF, not the plugs/wires, not the EGR, not a vacuum leak, and shouldn't be 02 sensors according to what I've read. I unplugged the battery and now I have the P1000 Drive Cycle Code that won't clear, even though I drove the truck up to the mountains and back (150 mile trip).
A new revelation is that under load and at low RPM (light accel at 55mph and 1800RPM) the timing starts swinging erratically from advanced +20 all the way down to +8 and +5. The big misses seem to come when the timing drops significantly and it shouldn't drop at all if the RPMs are increasing, right?
Does that mean it's one or both of the timing chain tensioners? I can't think of anything else that it could be. Even if it is a vacuum leak, would that cause the timing to swing like that??
Just looking for some input or if anyone has done this repair.
I know it's not the MAF, not the plugs/wires, not the EGR, not a vacuum leak, and shouldn't be 02 sensors according to what I've read. I unplugged the battery and now I have the P1000 Drive Cycle Code that won't clear, even though I drove the truck up to the mountains and back (150 mile trip).
A new revelation is that under load and at low RPM (light accel at 55mph and 1800RPM) the timing starts swinging erratically from advanced +20 all the way down to +8 and +5. The big misses seem to come when the timing drops significantly and it shouldn't drop at all if the RPMs are increasing, right?
Does that mean it's one or both of the timing chain tensioners? I can't think of anything else that it could be. Even if it is a vacuum leak, would that cause the timing to swing like that??
Just looking for some input or if anyone has done this repair.
Last edited by BroncoBundy; 09-10-2015 at 06:13 PM.
09-10-2015, 06:12 PM
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I also replaced the fuel filter about 10K miles ago and fuel pressure was good from the fuel rails, but only tested in park with various RPM. If it was the pump, is there anywhere in the OBDII that it shows fuel PSI? My Acton reader doesn't show anything but trim.
09-11-2015, 11:56 AM
#3
Yes these engine have varying timing. So thats not your issue. You like have a few bad coil packs and possibly it maybe time for ocygen sensors. I recently was chasing a similar issue. It just so happen to be a bad MAF.
09-11-2015, 02:55 PM
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Okay that is good to know about the timing. I played COP roulette a few months ago when trying to diagnose so I'd be surprised about a coil issue. What is strange is that sometimes it'll fine but usually when the AC is on it gets really bad.
09-11-2015, 03:37 PM
#6
Once again its more than likely COPs. If they are factory and have over 100k miles replace them along with a qaulity plug. IE motorcraft, Denso, or NGK. If injector coils were going bad it would only do it when at operating temp and would do it all the time.
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09-11-2015, 05:48 PM
#9
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Wild Timing Advance and Retard? 2003 5.4L 2V
A complete cycle of the computer is required clear the P1000. It's nothing to worry about. It takes all types of driving not just a 150 mile trip.
The computer does NOT read fuel pressure in any way shape or form. Have you swapped 1&2 coil and 6&7 to see if the issue moves to the new placement?
MAF, Vac Leak, FRONT 02 Sensors, Low Fuel Pressure all can cause lean conditions. Just cause you can't see a vac leak doesn't mean it's easily seen or found.
Wayne
The computer does NOT read fuel pressure in any way shape or form. Have you swapped 1&2 coil and 6&7 to see if the issue moves to the new placement?
MAF, Vac Leak, FRONT 02 Sensors, Low Fuel Pressure all can cause lean conditions. Just cause you can't see a vac leak doesn't mean it's easily seen or found.
Wayne
09-11-2015, 09:13 PM
#10
Wild Timing Advance and Retard? 2003 5.4L 2V
Originally Posted by Carcrazygts2
Once again its more than likely COPs. If they are factory and have over 100k miles replace them along with a qaulity plug. IE motorcraft, Denso, or NGK. If injector coils were going bad it would only do it when at operating temp and would do it all the time.
Speaking from experience here, it absolutely can be erratic. Chased this issue down on my number 8 cylinder a couple months ago. It was an injector.