i have a 1990 jeep Cherokee with a 4.0 when i try to get up to speed it starts to miss. when in park i can rev it up and it runs fine. also it takes 30 + seconds of tuning over to start. i put new plug wires, cap, rotor, and fuel filter. im lost as what to do next any ideas?

 

Have you checked to make sure the plug wires are all secure and in the correct position? That would definitely cause a misfire and a lot of turning over to get started. One of em might not be pushed on all the way causing it to run on 5 cylinders.

 

im having the same problem. anyone else have any ideas

 

did u replace plugs to?? they could be fouled!

 

The crank time is normal for that year... I'm with everyone else on this.. check them spark plugs!!! The gap should be .036-.040 if I'm not mistaken... Use yer senses... smell them. look at them.. White build up is normal, but if there is too much, I'd start looking into other systems (fuel, ignition coil, air filter..)