Hi there,

​​​​​I have a 2007 dodge dakota 4.7L that is acting weird. When driving home today it started shuttering, stumbling, or hesitating when accelerating around 30-35mph. It wasn't a hard acceleration, but it was not coasting.

My first thought was the throttle position sensor. I am ruling that out for now because I just replaced that about a year ago because my engine was cutting out at 70ish mph. Can it really be going bad this early?

Then when driving it later tonight, I didn't feel it doing anything while moving, but when I came to a stop at a light I could feel the engine doing the same thing as before. This time it was much more noticeable because we weren't moving at all, so it was forcing the car to shake a little and lurch.

After that I can effectively rule out the tps because I was idling right? Normally the sensor only fails when the throttle is at a certain position, which couldn't be at both idle and accelerating.

My third idea is the camshaft sensor. That seems like it could be causing all of the issues I'm seeing. What're your guys' thoughts?

My last idea was the idle air control. I can rule that out because my issues happen both at idle and accelerating, right? Is this still a possibly because I was not accelerating very hard when the issues happened?

Any help would be much appreciated, I don't want to just start replacing every part and hoping.

Thanks,
Jake

 

Was it replaced with an OEM sensor or an aftermarket sensor? If aftermarket, I would suspect it even more, rather than rule it out...These trucks are known to not like aftermarket engine sensors.

The throttle position of Idle is still a throttle position to be sensed...The sensor could theoretically fail at idle, part-throttle, wide-open throttle, or any/all ranges in between. Since not all failures are "equal", I wouldn't rule it out simply because it could be failing in more than one spot.

Could be too. is the check-engine light on?

I'm not 100% sure, but I believe that unless you've got the throttle at least moderately open, the idle air control valve may still be metering some air in until the throttle valve ("butterfly") is open far enough to supply all of the intake needs.

If, theoretically, the idle air control valve failed at or near the "closed" position, then not only would it cause significant stumbling while idling at a stop (which, as you said, the condition was more noticeable at a stop), but it may also cause stumbling while moving under light acceleration and/or steady speed when the engine is (or may be) expecting the idle air control valve to supply a portion of the intake air when the butterfly supply isn't enough.

If the RPMs seem to act normal as you rev the throttle at least moderately beyond fully-closed (but is only showing problems at and near fully-closed), then I would probably first rule out the camshaft & crankshaft sensors because failure of either would seem much more catastrophic to engine performance at every RPM.

If the stumbling problem truly only presents at/near closed throttle, I would primarily suspect the idle air control valve...And possibly secondarily (but not as likely if there's no accompanying RPM surging), the throttle position sensor. (And if the latter is aftermarket, get that out of there ASAP because if it's not already causing these problems, it may cause others in the future.)

 

I would agree with everything above that erau said, and I will add, when was the last time your throttle body was cleaned?

 

Yes it is aftermarket:
http://m.oreillyauto.com/h5/r/oap/si...osition+sensor

No it's not on. And no error codes have been thrown.

​​​​​​ That's really good info to know.

To get the oem tps, do I need to go to the dealership?

I should also note, I just drove it and I didn't notice anything. Both times this has happened has been after driving a short bit, stopping for a short period (5-15 min) and then driving more.

 

Honestly, I'm not sure. This is my wife's truck and she's had it since she was 17 (she's 25 now). I'm going to guess probably never, unless it normally happens in a tuneup/oil-change situation.

 

put some hightest 93 in it and take it for a beater, could just be some crap gas with water in it.

 

You can order OEM parts online. Here is one site which is good.

 

You can (which you may be able to call and they'll ship it to you, depending on the dealer), or there are some websites like dakotaff mentioned.

That could be indicative of when a micro-sensor (like the TPS) works well when cold, but not so well when hot as internal sensor tolerances change...But that's only speculation. I'd get that aftermarket one out of there first and foremost, then see what happens.

And as dodgeman1977 mentioned, if the throttle body ports have never been cleaned after so many years (which isn't a normal step during a fluid change, but possibly during a so-called "tune-up" depending on the servicer), then that idle port in which the idle air control valve operates may be excessively gunked up beyond the limit that the valve can compensate. However, I believe that in such an instance, it's supposed to throw a code/activate the check-engine light.

 

Another thumbs up on replacing TPS with OEM. I have found that you just can't use cheap parts in these trucks or any newer vehicle for that matter. The on-board computers are adjusting to very tight logic tolerances and cheap parts just don't have the legs to perform as needed.

 

The issue had gone away for about a week, but it showed up again. This time my wife was driving on the interstate with the cruise set, then she started to go up a hill and she pressed the gas pedal in further than the cruise had it set. That's when she started to feel the truck doing weird things.

I'll get the tps replaced with oem asap, because it's seeming like that is a probable cause, right?

​​​​​​The thing that still troubles me is there is no check engine light nor any error codes.

Thanks,
Jake