I have a 1989 Dodge Dakota Sport with the 3.9 in it. It starts up fine but after about 5 minutes of running in drive the truck acts like it wants to shut off, almost like its not getting any fuel. I've changed the fuel pump and filter and im about to change the distributor cap and rotor button. It only does this when its in drive so i have no idea what it could be. It has new spark plug wires on it as well. any suggestions to fix this would be great.

 

It could be the Idle air control valve. They are known to go out on our trucks.

 

Thats true...I didnt think about that.. I'll have to check that out thanks man..

 

Check out your EGR, i know it sound unlikely, but its most likely your problem....

 

I'm having a problem with my '94 3.9 much like the one you described. I've replaced the cap, rotor, plugs, o2 sensor, catalytic converter, muffler, PCV valve,Crankcase breather filter,water pump, and the timing chain. I've also cleaned the throttle body and the AIC solenoid and re-indexed the distributor. NONE of this has solved theproblem.I'm in the process of replacing thecoolanttemp sensorand flushing the coolant system. I'm also replacing the stock thermostat with a 180*If that doesn't help I'll check the EGR replace the fuel pump/filter/sending unit. I'll let you know what I find out.

 

thanks.. i just got the O2 sensor.. it just came in friday so im going to put that in tomorrow.. my dak is also throwing a code for speed sensor but i dont know what that is..