So as I enter month number 7 in trying to figure out what's wrong with my 4.7L 08 Dakota truck I am coming again to the form for some more answers that may help me fix my problem. Just a recap of what's going on for the past several months I have been having an very intermittent power loss when accelerating. It happens mostly when I am going up an incline or getting on the highway and it also happens when I let my foot off the gas then get right back on it. I can put my foot down to the floor when it happens and the truck does not respond it stays the same speed and rpm. Then about 30 seconds or so later the rpm will jump and the truck launches. So I have been all over the place trying to figure out the problem. I have taken the truck to 4 different shops, I have had the map sensor , O2 sensors, spark plug and wires all changed. I have had the transmission looked at and tested and they all assured me that it is not a transmission issue. I keep getting told that it seems like a fuel or ignition issue but yet no fix. I went out and bought a scanner and have been driving around with that and no codes have ever come up. I have preformed a fuel pressure test came back good, and the vacuum test was right where it should be, and the catalytic converter tested out just fine. So once again I'm back to square one with no idea what could be the problem.

So now the new question has anyone ever had any problem with the Accelerator Pedal Position Sensor or the Electric Throttle Body on their Drive By wire truck? And does anyone how to test them to see if they have a dead stop or are on there way out? Thanks again guys for all your help

 

Wiggle the PCM connectors and see if you can make something malfunction. Specifically #2 that's color coded Orange. If that nets nothing, tap on the PCM housing with a small hammer. Be sure to check the t-body throat and the hose going to it for any debris that might be rolling around.

 

So you hit the gas, and it literally does nothing? What if you try to accelerate more slowly?

On your scan tool, can you access throttle position? There may be some other PIDs you can view to help give you a clue.

"Stays at the same speed and rpm" -- Could this be a cruise control issue?

 

I believe the 2008's and up have an electronic throttle control instead of a direct cable connection to the butterfly valve...Therefore, if you hit the gas and nothing happens, that could mean it's not sensing the change in the throttle position. So yeah, I would agree it could be a bad throttle position sensor.

 

Yea that pretty much what happens. But it normally occurs when your past 25mph. So you would be driving and you feel like you need to go faster or get more power and you push down on the pedal and nothing happen. Whether you do it fast or slow it's the same thing no response for atleast 30-40secs, then it finally responds and goes. But the problem is so intermitiant that I would think a bad pedal or throttle body would do it all the time. But yea looks like I'm gonna have to try and replace the sensor or in this case the full throttle body and see what happens. As far as the cruise control I set it while driving and the truck acted the same way. So I don't know if its causing the problem or not .

 

If that's the case, since the cruise control doesn't require throttle input, the problem could be the throttle body itself or whatever motor actuates the butterfly valve.

 

I would look at the accelerator pedal position sensor. I would suspect that it's basically a variable resistor, aka a potentiometer. If you can get at it try spraying contact cleaner into it and work it back and forth a few times.