Well i have a new problem, im thinking its the oil pressure sending unit. But i ve also seen other things that can cause this problem. Well the title states the engine, and year. But at idle it sits at an even 35-45, if i drive slow it will start to bounce between 60 and 45, and if i give it more gas it maxes out above 80 and stays there. It happened on my old buick 3.8l. Im wondering if anyone can point out the main reasons for this problem, i just did my oil, spark plugs, wires. Im going to do the cap and rotor this weekend. Ive never seen it before and i used ac delco filter, and castrol gtx high mileage. I did a search and there was nothing straight forward on it.

Thanks in advance.