Need advice for my 1987 oldsmobile delta 88

I have had this car for a little over a year has less than 100k miles on it. On may 1st the car was running perfectly fine no issues nothing then on may 2nd it would not start, we turned key and wouldnt even make a sound. We thought it was the battery so took it to walmart where they tested it and the battery was perfectly fine so we called around to a few places to see what could be wrong and everyone kept saying sounds like the starter. A few people said try knocking on the starter and have someone turn key to see if it starts which it did advance auto parts said it may be the coil but we figured we would just buy a new starter and call it a day. Well our mechanic came over today helped get old starter off and put new starter on and the dang car still wont start then he found out the old starter was still good. We are lost for words trying to figure out what else could be wrong. O yea the battery is still fine and the spark plugs and wires along with air filter have all been changed in late february early march. Any help is appreciated.

Try starting it in neutral instead of park. could be the neutral/park safety switch.

Yep. Some basic tests: Turn the lights on and if they go on strong the battery is ok, if not its bad. Check all the cables and connections to make sure they are clean and tight from the battery to the starter. If its not the neutral start switch, it might be the ignition switch. I had trouble with that vintage and simply loosening the switch and adjusting it a quarter inch was enough to be able to activate the switch with the key cylinder.

Also make sure the alternator is ok.

I have a 1998 Olds 88, that had the same problem. It was the chip that goes in the ignition key. The mechanic had to take out the resistor chip in the PASSKEY and put it in the ignition wiring somehow. I dont know if your 87 model has this or not, though.

i thinkKeith is on the ball sounds like the neutral safety switch or a bad ign. switch

Does your key have a little black thing with a metal piece in in it. If so Richard Evans could right. These keys change resistance and cause the GM vehicles not to start.

The trouble could be one of the things mentioned previously. When you say nothing happens when you turn the key to START position do you get at least the warning lights to turn on and other signs of power? If you don’t get that then there is a problem with the power getting to the ignition switch.

In addition, it could also be the battery. The battery has to be able to pass a load test, not just show a voltage. I had a walmart battery that after one year, would not start the car, not even a click, yet it measures 12.6 volts with an digital voltmeter (DVM) and when put on a charger, it showed fully charged. It had a cracked connection internally that would allow voltage to be detected under a no load condition (DVM) but would not pass current, so it showed fully charged with a charger.