Changing distributor on my 99 Jeep Cherokee????

[Turbodan]

My distributor on my 99 Jeep Cherokee has been making noise when cold. It goes away after 5 minutes. I was told it sounds like the bearing in the distributor shaft is going bad. I bought a new distributor. After I pulled the cap off I noticed a black thick hard carbon on the inside of the cap contacts.
Is this normal? Should I get a new cap and rotor? Will changing the cap and rotor make a difference in gas mileage or how it runs? I do not know how old the cap and rotor is on the vehicle. Not sure if the carbon builds up after 1000 miles or 60,000 miles.

[CMYZ28]

cap and rotor are cheap, might as well replace them

[Sean124]

oohh boy. You better make sure you get the new distributor lined up EXACTLY where the old one was or else the cam crank sync will be off and the thing will barely run.

Sean

[1BADAIR]

does the 4.0 have the bushing in the block like the 5.2 5.9?

[dave89iroc]

does the 4.0 have the bushing in the block like the 5.2 5.9?
not that i remember


sean is right, cam sync is critical


if you can get it to run ok, find someone who can check cam sync with a scanner

[Turbodan]

I have the rotor marked so everything goes back together the same. The end of the rotor tip is about 10MM wide so I am sure if I am off a degree it will still run ok.

[Sean124]

I have the rotor marked so everything goes back together the same. The end of the rotor tip is about 10MM wide so I am sure if I am off a degree it will still run ok.

It will not run it has to be dead nuts on.