1990 Pontiac Sunbird 4 cyl Front Wheel Drive Manual 150000 miles
I have a 90 sunbird.2.0L-5 speed. The car died 1 day. Couldn't hear the fuel pump. So I replaced it with the relay. It happen the next day. Found out that with the brake lights on or parking lights or in revese the pump shuts off. Just fond out that when it starts running bad, like its going to do it, the rear parking lights are at 1/2 votage. Like its pulling a ground. It happen al of a shadden. Car ran prefeted befor this. It only does it after 10 to 12 miles. Not under 10 miles.
I found my promblem. It was the ground wire going to the rear of the car. Gm ran 1 wire [18 ga. ] To the rear. It is spilted into the harness behind the rear seat and grounded to the body next to the front seat bolt by the sill. Right wear you kick off all the snow and rain. At the harness it has 4 18 ga. Wires coming off it.I ran a 12 ga. Wire from the batt. To to the harness. It rans so much better now even than before. It was an ongoing promblem that finly gave out. So please people check your ground wires.I hope this helps other people.