Rpm noise problem
Any one have a clue what's causing this I have a 87 jeep 4.2 with 400hp on it duraspark distributor and ignition. Been rining it for 2 years now all of a sudden I get p0335 rpm noise and my tack and rpm on handheld will jump and be erratic but dosent happen all the time any help would be appreciated
ringing ???? does it sound like a bell or like a dragging dinging sound that to me sounds like detonation bad you can melt holes in pistons burn off a edge of a valve each will cause a power cylinder pressure causing miss fires don't know if that's it but any time I have heard that in either nitrous cars or blower cars or higher compression engines with lower than 87 octane or timing way off or really lean you engine will let you know by what sounds like bells or a ping noises just fyi