My 1997 regency want start at times all the lights come on but the engine wont start up, and when i turn the key, there is no sound, then, sometimes it will start, I had it put on a codeing machine and it says everything is fine so whats wrong?

SOURCE: When I go to start my car, it sometimes will not start

weak battery. or dirty bad cables. check alternator out put .make its charging battery.

SOURCE: check engine light comes on upon start up

alot of cars show a crankposition sensor on a test if it was bad car would not run unless you have a problem with car stalling or running bad when it gets hot not a ignition module if car still runs good not a major problem one problem would be a bad 02 sensor does not mess with car alot gas milage loss mabe slight hesitaion look at sensors that dont mess with engine if not 02

SOURCE: 1997 oldsmobile cutlass supreme

This Too Is A Starter Problem, If >>The Battery Terminals Are Clean <<And >>The Starter Terminals Are Clean and TIGHT <<,I Would Wait Till It Wont Start Again and SMACK THE STARTER 2-3 times with a HAMMER then Try Starting it. If It Starts then it is The Starter. I KNOW this seems A Little UNCONVENTIONAL BUT For 30 Years This Technique Has Diagnosed HUNDREDS of STARTER Problems for me.

SOURCE: 1998 oldsmobile sometimes starts

Battery could be not holding a consistent charge. If not, Voltage regulator, starter motor or starter solenoid need replacing....Bad wire connections to all 3 also possible. Voltage regulator should be least expensive to try through process of elimination

SOURCE: 1997 Oldsmobile Aurora wont start, problem with security key?

sounds like the vats system try cleaning your key wait 3 min if that doesnt work take it to the dealer and let them reprogram the vats system and probally replace your key