Hello

Im having a problem i down shifted one day and it mad a puttering noise now every time i step on the gas it bogs down to about 500 rpm then picks up does this every time i aplly the gas ... Also I have to hold it to the floor for it to start wont start on its own anymore... Idles runs good once revs pick up jst the initial stepping on the gas...Please help

 

fuel pump (verify ). fuel filter (change it ),
do these check first !

 

Also check your lines for small leaks.

 

take a look at the distributor post

i've had similar cause/symptoms with my XJ when it went out...

What i think happened:
when you down shifted, the engine RPM's raised the RPM's faster than the distributor would rotate, and this snapped the shaft inside that connects the gear on the cam, to the distributor rotator...

Whats happening now:
since its broken, when theres "excessive load" it separates the two pieces of the shaft, it goes on the frits from the other cylinders misfiring out of time...

you might need a strong magnet on a wire to get the broken part out, depends on how/where it broke. (it shouldn't go anywhere when you take it out, mine didn't) no promises

hope this really narrows down the search for ya