I have a 99 Dakota 3.9 2WD 5 Speed. I will explain my day when the outside temp is below 50 degrees. I start it up and there is a breif hesitation while cranking. Then it fires up good. I drive about 5 miles and it starts spark knocking like crazy. Running on 1 cylinder. And the Tachometer is flipping out. Bouncing from 0 to 6000. Then after a mile of keeping the pedal to the floor, it suddenly smooths out and runs perfect for the rest of the day.

On a 30 degree day, forget it. It won't even start. It sounds like it is trying to fire but its like the timing is out.

60 degee day, it runs perfect.
The check engine light comes on if it dies but only gives a misfire code.
The dealer took a quick look without diagnostic and said "the computer needs replaced. Give me $500" But I don't have the money for guess work. Other dealers want $50 to check the computer.

Please help. This truck is driving me crazy. Its a great truck and a gas saver, but if I have to wear my coat in the morning, then I drive the gas guzzler instead.
Thank you

 

I have the IDENTICAL problem. Did you get any solution to this?

 

i dunno what it could be...try checking all the spark plugs, if ones damaged and so forth replace it, if it still does it, either the timing slipped for some reason, or somethings goin on with the pistion, check all your spark plug wires to make sure non of them are shorting out or have cuts in the wire. i dont know if a severly clogged fuel filter or possibly a dying fuel pump would do that or not? sorry im not to much help

EDIT: also check the distributer and starter, i had an s10 that whenever **** under the hood got wet, like when i took it through a car wash it would run like that then die, and wouldnt start

 

I would give it a complete tune up. replace cap/rotor, plugs, wires and that will help out alot.

 

Sounds like condensation getting in the distributor cap to me. Replace the cap/rotor/plugs/wires. Make sure the cap is sealing properly.