Power steering drops out when rev's drop.

Is the pump new, rebuild or used?
Did you clean the reservoir?
Was fluid dirty?
Is belt tension correct?

The pump is a rebuild swap, the old was the original. Everything is spotless clean. All new fluid due to a leaking sender which was replaced. Belt tension right. We have checked all the oil lines are not blocked and are cleaned with high pressure air. And bled the lines.

You should be testing the pump pressure. The rebuilt pump is the one likely to cause this problem.

The problem is the same and we have tried a pump that is working perfect in another car. Plus the exchange pump. So that is 3 pumps and the same problem. Do the senders have any connection to the computer elements of the car.

The pressure sensor is linked to the engine computer. Its main function is to signal to the computer that there is additiobnal load on the engine when power steering is turned during idle so that the computer would increase the idling speed if necessary.

If the idling speed drops too low, it means the idling speed is not being compensated by the load produced by the pump working under pressure.

If the idling speed is not stable, it could be due to the idle control system and celaning the throttle body and IAC would help.

Thank you for your time. We replaced the whole Rack and the problem is solved. Our son died and I did not get back to you sorry.

Sorry to for the bad news and we would like to extend our condolences.

Thsnk you for the feedback.