I own a 98 Dodge Ram 1500 4wd. 5.9L. I blew my engine and installed a 2000 dodge Durango motor in it. Now the problem I have is only 4 spark plugs are firing. Cylinders 2,8,5, and 7 aren't firing. They fill up with gas and the engine dies. I have changed the map sensor,the rotar, Dis cap,spark plugs and wires, cam sensor, crankshaft sensor, tested the tps, tested oxygen sensors. I am at a lost. Any suggestions would be greatly appreciated.

 

welcome to DF!

when you did the motor swap did you swap flex plates? the only thing that comes to mind is maybe your crank sensor is not detecting 8 cylinders off the flex plate.

put a timing light on the coil and see if the coil is firing 8x, unless the PCM has a problem I cant see why it wouldnt fire on all 8 cylinders...

 

Is it a new motor? Do a compression test on the cylinders that aren't working.

Are they not getting any spark? How can you be positive that the reason its dying is because those 4 aren't firing?