troubleshooting

Over the last couple months my arrow's fuel pressure gauge has been on the fritz. For a while it was jumpy -- oscillating wildly in the green back and forth like a metronome. Then it would read near 0 after start-up and during taxi, but then come up and stabilize in the green during run up. Now...

We have a CGR-30P in a C182, installed about 4 years ago. It periodically gives readings across all parameters very high or very low (fast jumps - then back to correct readings). Have rechecked connections and grounding (2 different shops). Getting it looked at again, but wondering if anyone has...