1)OVP ?,an easy check ,fuse sit inside this piece ,located at the battery area.
2)Alternator making enough juice at idle ? pull the wire from the back of the alternator ,a regulator sets into this area ,has to metal rods that wear ,you can replace this for $25 while its still on the car ,pulled my alternator output from 12.5 ,no good ,to a healthy 13.8 at idle.This is very important to have the car performing well at idle.
3)tO FINALLY GET MY CAR RUNNING RIGHT I had to completely clean out and seal my rusty gas tank on my 190e cossie ,I then worked my way through the fuel system with a fine tooth comb.New fuel pump ,fuel filter ,cleaned the fuel distributer with sonic cleaner ,if you do this its important to ready a few threads off 190 rev for details .The easiest way to check for FILTERING ISSUES IS TO DEMO ,CUT OPEN YOUR OLD FILTER, you want to soak it in water the drain before cutting it open .Youll be looking for rust particles ,in my case it was like looking at a dirt road inside a can.It can also be just a weak fuel pump , if you just do these 2 things its something you wont have to worry about latter on. In your case you have 2 pumps.Very important to play it safe when working at a tank ,you can squeese the main feed line with a pair of lg vise grips to close off the gas and when you crack open the filter or pump lines you will see some spray so rags w/ gloves and always disconnect the battery!