Sometime ago my mechanic replaced sparkplugs and ever since truck will run well for a while then backfire and shutoff . Since that time the following have been replaced coil twice sparkplugs engine wire harness from engine to computor had to use one from a salvage as a new one is no longer available crankshaft sensor twice distributor. Truck has 120,500 miles.The mechanic mentioned tone ring in the engine block what is it?

 

Spark plugs? Spark plugs??? I don't think you meant to post this in the diesel section. LOL...

Moving to proper section...

 

Go to an auto parts store and have them test your battery before you keep replacing a bunch of other parts.

 

To answer your question, the tone (or pulse) ring is attached to the flywheel and has a series of notches that are read by the crank sensor as they pass by.

How is he determining it's the pulse ring? If it started happening after a plug swap and/or cap & wire replacement it's very likely the mechanic simply misaligned the distributer. Are you getting a camshaft or crankshaft sensor CEL???