Having some issues with a bobcat that was given to me by my grand. Father before he passed. When I first got it it had been sitting for a few years so changed all the fluid everything ran fine after sitting a month or so it ran fine but started shutting down on high oil pressure code so I got a new sending unit no change. Bought a manual gauge to see what pressure is but now all I can get it to do is click when I turn the key. Any suggestions