tracker1991

hi, decided to get some opinions, 1991 tracker took it in for a tune up and to get the gas gauge fixed. they pulled the gas tank and found it was the wire and fixed it plugs and wires replaced. since then intermittent starting issues or staying on for long. then they had issue turning the ignition key... I went and got the part whole new system with key. they replaced it. still having issues running. Now it wont start at all. the starter had been replaced previously to the tune up. now it wont start. They have pulled the ecu unit; 33920-56b30 standard trans 2 door 4wd; they say thats the problem now. I opened it and the computer looks fine. is there a way to test it with out being connected to the car? I took pictures of it can anyone please look to see if they see any issues with it. Car is driving me and the shop crazy. also there had been some weird bee sound at times under the dash and every once in a blue moon it would not start but then ran perfectly for months. that is why i went for a tune up hoping to resolve the issue not make more...