Trim/Tilt problem under power
 

The trim works just fine when the boat is sitting at idle. When the boat is cruising under power, the trim is very sluggish. I've noticed I have to hold the switch down for a period of time and then the trim will raise. When doing so, I have noticed there is a slight change is engine rpm then the trim switch is pressed??

Fluid level is OK. No leaks that I see. Could the pump be bad? Bad switch on throttle? I just replaced the ground cable from the block to battery #1.

Boat has a 97 454 MAG MPI if that helps.

Thanks for the help!

Is the power and ground wires to the trim pump hooked up to batt,#1 or #2 or the batt, switch it self ? maybe that batterie is weak and the other one is good. Also if you are watching the trim gauge and waiting for it to move and it is taking some time, then maybe the trim gauge or the trim sending unit is bad or out of adjustment, Or the ground wire to the gauge is bad. Also could try turning on the key and have some one watch the trim gauge and find the trim sending unit wires on the out side of the boat by the u joint belows on the right side and wiggle the wires to see if the gauge moves on it owen. Also you could try putting some wait on the drive to see if you get the big delay you are seeing.