So i've got a notchback fiero, the two lights on the left I can not figure out how to get them to stay on. Sometimes I can unplug the lights from the sockets and they will work for a time maybe a day then go back to there old ways. The blinkers work and the flashers work, but the two lights on the left will not come on for running lights or all lights on. Any suggestions?

Also I have an electrical issue where, for example I am sitting in the car at a redlight idling the cars volt meter will start to jump up and down, and the car sounds like its going to cut off, i remedy by giving alittle gas, sometimes this happens and sometimes this does not. Any suggestions?

I would start by checking the ground wires in each area. This may take care of your problem.

Also double check the bulb part numbers, cars this old can get a mix (one tail light pulled and bulbs replaced, but not the opposite tail). In this instance, I've seen 1157's installed when the correct bulb is 2057.
This mix-up can cause issues like you are having. The bulb fits, but the filaments are different. I learned this the hard way when I replaced a front turn signal bulb on one side only with a brand new 1157 I happened to already have on hand and I thought "why spend more money?". End result? The brand new bulb would NOT work.

Always reference the fiero sails bulb page to verify the correct bulbs bought and installed.

Fiero sails bulb guide

Im confused where the ground would be on the light system, each light doesnt have its own ground. So where does all the lights wire run to? If it were a ground issue wouldnt all of them do it.

Light bulbs wise I have all the same light bulbs in the whole rear, all LED's. Before you get to the resistor to put a load on the lights, I have already tried that it didnt make a difference, also I have swapped in standard bulbs and still gives the problem. The light is there in those two but very low so you can barely see it.

quote Originally posted by timenewton: Im confused where the ground would be on the light system...

The rear lighting harness ground is attached to the passenger side upper frame rail behind the rear plastic wheel well liner. I'm not saying this is necessarily the case here, but often when the upper frame rail rots away, this ground point degrades/disappears.

This is a well documented problem with many LEDs. Go to the Ogre's Cave.