My car sometimes does not want to start after trying to come home from an errand or other short distance. This usually occurs when it is really hot outside as well.
I took it to AAMCO to get diagnosed and they brought up the codes and told me that my Knock sensor, CAM sensor, and MAP sensor are all bad.I've been calling around for second opinions and everyone has been telling me that all 3 of those sensors are unlikey to go bad at once. How do I find out what the real deal is? Everyone wants 1000-1300$ in repairs. I dont want to pay for this if its not necessary.
Next time it refuses to start don't wait for it to make up its mind-do below immediately to determine if its fuel or spark problem
Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 away from ground-have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if okay-check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,cap and rotor,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it and keep testing
If both fuel and spark is present-check the valve and ignition timing, this will lead you to problems
with compression and valves opening and closing at the wrong time/broken or jumped timing