I have a 93 Dakota with a fuel injected 3.9. When cold the truck will barely idle (about 300 rpm), it'll back fire, and pushing on the accelerator doesnt really do anything. Also the idle air valve is sucking in a dramatic amount of air. If I unplug the map sensor, the idle air valve calms down, the backfiring stops, and it idles smoother, but it usually dies. If I let it warm up for 30-40 minutes, it's perfect like nothings wrong.

I've tried throwing money at it, but nothing's helped.

Replaced:
idle air sensor (twice), egr valve, 2x coolant temp sensors, crank sensor map sensor (twice), ecu, Fuel pump, Fuel filter, Plugs, wires, cap rotor (twice), distributor pickup, battery, muffler

I also cleaned the throttle body, ran a bunch of different fuel system cleaners, checked all vaccum lines, added more ground wires, checked for oil in the intake

Any ideas?

 

Considering you have already stuffed $20's down your intake to try and fix the problem I would say also replace the 02 sensor. How many km's/miles on your truck? Was it running fine in the warmer months? These trucks have hideous wiring issues, so every bit of info you can give us will help you track down the problem.
Cheers, Spinner

 

have you checked out your ignition coil? if you dont know...
An Ignition Coil is an induction coil that changes current from a battery into the high-voltage current needed by spark plugs of an internal-combustion engine. It receives a quantity of electrical voltage from the battery and ladders up the low and quot primary and quot voltage and amplifies it into a big jolt of voltage of about 20,000 volts, and sends it to the spark plugs via the distributor.