Fuel pump relay clicking 400e

[jc300e]

When the car is cold, I have a clicking sounds coming from the fuel pump relay under the rear seat. Once the car is warm, the clicking stops. Performance is normal when a operating temp. When the clicking is taking place, the engine stammers at the cadence of the clicking. Fuel psi bounces to the same cadence at the fuel rail test port. At operating temp, psi is steady and normal.

I've replaced the pumps and the fuel pump relay and still have the same symptoms.

Suggestion?

92 400e 260k well maintained miles