I have an Autometer mechanical fuel guage plumbed straight out of my fuel rail. Just recently the guage has begun to vibrate or pulse. The guage holds pretty steady at idle, but begins to pulse under load and gets worst with more RPM.

I have a boost referenced regulator inline before the rail with a return to the main feed line before any filters or coolers. I have been running the guage for 3 years with no probs. Only chage this year is bigger feed line from the tank and larger ID filter head and filter (primary filter/seperator)

Any idea's what may be causing the pulsing all of the sudden??

Nuthin??

Guage going bad?
Injector going bad?
Feedback from return line?