Bill;
I was measuring fuel pressure to the
fuel rails to verify the EM2 calibration. The needle on the gauge was
swinging very rapidly from about 20 to 40. I don’t recall what RPM,
but I guess near idle. Perhaps stating that “it is not good”
is an overstatement, and perhaps it just happened that the pressure pulses hit
a resonance in the gauge; but my judgment was that it could affect the engine
operation and could be damaging to something else long term. I had
already put damping in MAP line to the EC2, so I decided to T it into that
line, and the pressure pulsing went away.
I have a 3-barrel TWM TB on a short
intake manifold. The MAP sensing ports are just downstream of the
throttle plates.
Al