High Idle/ Cam Code

[toddrs93]

Hello I have a 2003 Ram 4.7L.

First off I am an auto technician so I am not completely lost, but 90% of what I work on is foreign cars. This is my personal truck, and my first go with the 4.7L engine.

I purchased the truck running, but with a blown headgasket. There was a questionable engine noise which may have been bearings, but not loud enough to give me a huge cause for concern. Money is tight so I decided to try to get away with just replacing the headgasket.

I completed the job and it starts right up, but idles at around 3300rpms. When you give it any gas it just bounces off 3500rpms as if its stuck in some kind of limp mode. The motor seems to sound OK though its difficult to hear with the high idle, there are no signs of any other damage.

The only code I get is a P0016, Cam/Crankshaft position correlation sensor. Both the cam and crank sensors seem fine, wiring is fine, and they were fine before. Throttle body, IAC, TPS all seem to be OK. I think the cam code is an indication it jumped time, however I have never heard of an increased idle from jumped time, and it seems to run OK. Maybe I have more than one problem but I would really like to figure out the idle.

[Chris Stewart]

Because it's a "fuelie" and not carbureted, I'd look for a big vacuum leak or the IAC stuck open.

[toddrs93]

Inspected and cleaned the IAC, appears fine.

Update, I went back in and verified all timing is correct, replaced a faulty coolant temp sensor, started it back up and its even worse. Just goes to 3500 and bounces off like a rev limiter. The only code this time around is P0121- TPS/Pedal position sensor. I replaced the TPS and no change. The only time I get it to come down is when I shift into drive. When I shift into Reverse it goes even higher, to like 5500rpms. I'm running out of ideas.

[hundahunta]

re-check your code p0121 is for a 5.7 tps code

[toddrs93]

Originally Posted by hundahunta

re-check your code p0121 is for a 5.7 tps code

I have several times, its definitely P0121. My scanner defines that as TPS/PEDAL POSITION SENSOR A CKT RANGE/PERFORMANCE

It may very well mean strictly a tps for a 5.7l

[hundahunta]

what is the tps reading at idle??

[hundahunta]

theres is the pcv hose at the back of the intake manifold make sure that is not torn or it fell off

[toddrs93]

Originally Posted by hundahunta

what is the tps reading at idle??

have not checked it but cleaned the throttle body and put on a brand new tps

[toddrs93]

Originally Posted by hundahunta

theres is the pcv hose at the back of the intake manifold make sure that is not torn or it fell off

yep that ones on there ok

[Chris Stewart]

Ok, here's the APPS/TPS Reset,
Turn the keyswitch On/don't start the engine,
Slowly mash the throttle to the floor
Slowly release the throttle
Turn the keyswitch Off.
Now start the engine.