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2001 V6 4.2 auto F150 no power AT ALL at low rpms

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Old 04-29-2012, 04:14 PM
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2001 V6 4.2 auto F150 no power AT ALL at low rpms

okay, so i have a f150 automatic with about 80k miles. out of no where it just lost all power.
i have since replaced the camshaft sensor and synchronizer together
(it was all chewed up from the sensor falling apart inside).

replaced the the dpfe sensor aswell as another sensor thats attached to the passenger side of intake manifold with two lines running.
(1 vacuum line runs behind intake towards another sensor on driverside near brake booster that i couldnt locate at oreily or autozone).
it does react when i disconnect that same plug on that sensors aswell as all other sensors. (idle becomes rough).

i've had the tps sensor replaced, and a sensor on the of the manifold near the throttle body i dont recall the name of it.
ive disconnected the exhaust manifolds before the cats.
cleaned and tested maf.
seafoamed the hell out of the vacuum lines and intake manifold..
i removed throttle body and attacked it with seafoam and q-tips and it is not clogged at all.
i've removed all intake manifold vacuum lines while truck idles to check for pressure and vacuum pressure is present (strong vacuum pressure actually)
i also checked a T-valve near the battery and it has strong vacuum pressure aswell.
coil pack, plug wire set, spark plugs all new.
new egr valve.
new fuel filter, pump primes and pressurizes well.

truck still gives me the p0104 code, differential pressure high output circut code.

basically truck idles good, once i apply any amount of throttle it lags a bit.
as soon as i put it in gear rpm drop below 1k and never come up at all.
as i give it gas it struggles more, until i let off the throttle seems like the engine catches up or theres a momentary sweet spot where the truck feels normal and moves forward about a foot than back to the usual struggling.
it really happened out of nowhere.

any suggestions.. i feel that ive exhausted all my options i can think of.. only thing i can think of is taking it to the dealership and having there shop investigate the issue soo please if there's anyone that can point me in the right direction?
 
  #2  
Old 04-29-2012, 05:08 PM
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It sounds like your IAC valve (Ford actually calls it an Idle Air Bypass valve)
isn't working for one thing. That would cause the idle RPMs not to stay up when you
put it in gear. I'm not sure if it would cause the stumble when you accelerate though.
 
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Old 04-29-2012, 05:27 PM
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thats new too, i just couldnt remember the name of it off the top of my head. its the valve attached to the top of new the throttle body, somewhat has the shape of an injector sort of.
 
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Old 04-30-2012, 10:09 AM
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still nothing, ive cleared the code and it continues to do the same thing.
continues to run as if either its running with now power as soon as it goes into gear and for a split moment when letting off the gas it reacts normally and leaps forward a foot or so as the RPMs drop then its back to rought idle in gear.
 
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Old 04-30-2012, 11:30 AM
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Start all over. Your in confusion.
What codes do you get?
If 104 is one code, it involves the Mass Air meter circuit.
If this circuit is faulty the motor won't make any power without the signal from the air meter telling it how much fuel will be needed per the rpm/airflow.
Normal idle is about 650 +/- 50 rpm hot.
IAC has little input above about 1000 rpm as it's main function is to control idle only.
The camshaft position sensor controls fuel injection timing and must be set in and 'timed' correctly on a v6 motor.
Somewhere here you have something wrong.
 
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Old 05-02-2012, 11:12 AM
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could it be that i stabbed the cmp off a tooth that would have it running the way it was?
it started with the cmp being crapped out.. i'll post a picture of it. kind of ridiculous how it failed. i'll recheck the way i stabbed it. i beleive i stabbed at tdc. is there a particular way of doing it? ignition on/car off disconnected cmp for 10 seconds.. etc, etc...?
 
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Old 05-03-2012, 12:51 AM
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Get a copy of a Haynes manuel.
Look at pages 6-11 and 6-12.
 
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