That is what the OVP looks like. But, it should be behind your battery on the passenger side (in my '91 there is a plastic cover that has to be lifted out to expose it behind the battery. It (OVP) faces to the middle of the car and sits with the red cap towards the top of the car. When it isn't working, the car runs very rough and you usually get the ABS light coming on from what I understand. One of the other hundred things you can check is the Idle Air Control Valve. It's under the front side of the air filter housing. Has a black air hose that runs from one side to the fuel assembly and the other to the manifold. I found that my hose on the fuel assembly side was cracked (and so have many others) and caused a "hunting" idle issue and tough starting problem. You can also take it off and clean it out. Some say theirs were really dirty inside (mine was very clean). Other things that can cause the issue that I've come across...O2 Sensor burned out giving erroneous signals, Water Temp Sensor ($30.00), Air Intake Temp Sensor (you would think this thing lasts forever but they don't...located on the air intake bridge to the air cleaner assembly $25.00), cheap 1.99 Copper Plugs from Autozone (get some and put in), coil ($70.00) and rotor ($35). Did anyone ever mess with the air mixture that's accessed from atop the air cleaner assembly? If richened or leaned too much, will cause that problem.