My 120 gives erratic oil pressure on take off. It is fine the rest of the flight. It spikes from zero to max, then settles down. It is installed on a flight design CTLS and has 150 hours . Where do I look to settle the problem?
Most probably a bad ground. I lost half of my hair tracking down bad ground problems on an 18 year old plastic airplane.
My problems were mostly with oil temp, not pressure, but I believe you may benefit from my solution. The ground must be dead perfect between the sensor and the grounding point for the Dynon. Likely culprits include the thread sealant used to prevent oil leaking, which block a good ground, or simply a bad ground strap between the engine and the aircraft chassis / avionics ground.