My son has a 1989 Pontiac 6000 that was running fine. Recently, in thelast 4 months it has developed the desire to quit running after 23-28 minutes. After taking it to two separate mechanics and spending $800 for what were supposed to be sure fixes for it, we have resorted to process of elimination. The mechanics changed the o2 sensor and the radiator.
Since that time I have replaced the o2 sensor again,replaced coolant level sensor, the coolant temp sensor, all of the relays by the front right headlight, the fuel pump, the fuel filter twice, the module and all 3 coils, and spent endless hours banging my head on the wall. It still will only run for 25 minutes then dies. When it dies it will not start again till it has apparently cooled down. Help?!!!!