so yeah, ive had this ongoing hesitation issue. everything has been cleaned, replaced, checked and whatever. except for the distributer. i have the 99 xj, so it should have one, right? 2000, or 01 was when they went distributerless... the cap and rotor have been done. also there is that whistle/whine sound cause i got a manifold bolt loose (is my understanding) thoughts??? thanks.

 

Tighten that all the manifold bolts,it could be sucking in enough air to throw of the computer. Just my 2cents.

 

Also, check your vac hoses. I had a similar issue in my '96. New hoses cleared it up almost immediately.

If you can't be good, be good at it!