01 Lightning 55K Miles RPM issue

[Rocco6685]

Have an issue with my 01 Lightning. The other day I noticed that the truck out die and almost burp, the RPMs would jump down almost to stall then jump back up. Then today the gauge FLEW to 0 then literally jumped back to 2k RPM. Got some new gas, put a new fuel filter in, wires and plugs are new.

Any idea?

 

[DSG2003Mach1]

does it only have issues at idle? could be an idle air valve going bad, if it has any issues when your foot is on the throttle thats probably not it

if you have a handheld you could always try logging fuel pressure and see if its dropping for that to happen, maybe a dying pump?

 

[10 sec L]

How old are your coil packs? and check fuel pressure