I recently got an '01 with the 3.9L v6. Love the truck, but it doesn't seem to be running quite right. It has 45K miles and has been well maintained. It has a really rough idle in park, which smooths out when stationary in drive, but you can tell it's still there. Also, it hesitates and bogs down like it's gonna die when you put your foot in it from a stop. Once it gets moving about 5mph, it smoothes out and runs fine. I've tried changing the plugs and wires, checked the dist cap, replaced the bypass hose, switched to 89 octane and run a bottle of 44K fuel tx through it. Still no significant improvement. Any advice? (other than someone telling me I should have gone with the V8! ) Thanks!

 

OK...finally broke down and took to dealer. Tech said whoever had truck before me tweaked the throttle body idle set screw. He said the throttle body is factory set, and is unable to be corrected aftermarket. So now what...replacement of entire assembly? Will a JET chip help correct this?

 

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That's what I had in mind. I'll see what I can scare up...thx.

 

BTW...I've heard that putting a throttle body assembly from the 4.7L V8 in place of the 3.9 OEM TB will drastically increase performance and HP. Anyone heard of this? Is the mainfold compatible?

 

I don't think you can take the TB off the 4.7 but the 5.2 TB will fit, it's a few mm larger is all, I don't think it's drastic and it would prob only be a wide open trottle thing. Anywho on the Throttle positioning sensor thing, there is nothing to set on the dakotas really, I mean it has 2 screws on it, no adjustments. I would just replace the sencor and see if that fixes it, all I know that could be done is either bend the sensor I guess or place a resistor inline somehow. I have seen some throttle body tweaks on the net for those trucks but it seems ignorant. THis is going to sound insane too but just before the battery died on my 2000 dakota with a 3.9 it was doing some crazy stuff like not idleing, hesitating, and well thats prob about it, shortly after the battery wouldn't start the truck, new battery and all is well. It's some food for thought, computers are sensative to that type of thing. Hope this helped!