I have a 96 dodge ram 1500 5.9l v8. when i start it up in the morning she runs fine but driving down the road 4 about 15 to 20 mins she falls on her face and barely goes 10 miles an hour. wait about an hour she'll run fine again 4 awile than do it again.any suggestions i can't figure it out tried about everything i can think of.

 

Cat may be clogged/bad 02 sensor

bad plenum gasket

may need plugs/wires/dist.cap and rotor

 

i cut the exaust all the way off , new cap,rotor button, plugs and wires and checked the coil

 

cut cat off ,new plugs/wires/rotor/cap, checked coil

 

plenum gasket then

look down into the TB if theres pools of oil, its gone, but your best bet would be to take off the TB and look in. you get better results. from first hand experiance

 

took the throttle body off looked in and it is clean no oil nothing but tb itself has carbon build up and crap on it

 

try cleaning that up. the butterflies may be sticking, but i dont know if that would cause the engine trouble you described

 

Does it have an EGR? If so you might remove & clean it as well as checking the passage in the intake.

A simple resistance test is not enough to rule out the coil as the following Tech Tip states:

http://forparts.reachlocal.com/coupo...%253Dyfp-t-701