Lostfisher1

How do i tell if I have a bad cap or rotor. Can this be cleaned or replaced? I have a rough idle and would like to fix it. Also how easy is it to replace.

DieselD

Very easy, but do the whole tune up


Cap, rotor, plugs and wires.

thomas0202

Might as well do the air filter while your under the hood. Might do the fuel filter also if it hasnt been done in awhile. I can imagine a dirty filter could cause a slight fluctuation in fuel pressure which can lead to rough running

Firestorm500

If the cap and/or rotor is bad, you will see burn marks and carbon tracking on the underside of the cap at the terminals.

They are pretty cheap, so replace them if there is a question of their fitness.

jj1562

I just did my cap, rotor, plugs and wires, the plugs were double the gap of .60-.65, the cap was burnt a little and the prongs where the wires attach onto the cap were rusted, I'm guessing the guy before me went through some water, but she still ran great lol love the 4.0

jj1562

Also, when you do the wires, take one off at a time and place it onto the new cap, if you mix up the wires, she'll run like crap

cruiser54

Factory recommended replacement was 30,000 miles on plugs, cap, and rotor. We also replaced the wires at 30,000 instead of the recommended 60,000 because they seemed to fail before that interval from being handled at 30,000.

So, in a nutshell, replace it ALL at once. Champion or NGK plugs, Napa premium cap and rotor and Napa Belden lifetime wires.

Clean the throttle body. Replace the fuel filter.

Lostfisher1

Wow was that easy. replacing the cap and the rotor consist of removing 2 screws popping off the cap take the old rotor out put the new one in and put the plug wires on the new one. I didnt do the wires yet thats another day. but it seems to idle smoother miss is still there. I kinda felt like I was wasting money because I didn't notice any difference. but there was metal shavings and alot of corrosion on the old one.

cruiser54

Do the wires soon. Yo udidn't waste money.