2003 Mercury Marquis • V8 2WD Automatic • 85,000 miles

2003 Mercury Grand Marquis no start hot issue, after it's been driven for a while, BUT only when it's really hot outside (80+ degrees), like lately. My dad was driving this car today and after driving for about a hour or so, he went into a store, came out and no start. The car has to cool almost completely before I'll start most of the time and sometimes he has to feather the gas pedal to keep the engine running if he can get it to start. Last year we had the crank sensor replaced with a OEM one, thinking that was the issue and that fixed the problem for about 9 months but now the problem is back. We took it to a Ford dealership and since it wasn't hot outside (it was in the mid 70s) they couldn't duplicate the problem. The did however say, they found a crimped wiring harness back by the trunk, charged my dad $900.00 to fix it and the problem is still there, like I said it just happened to my dad today again, since it's hot as hell outside.
July 19, 2011.

Hot or Cold

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

Jul 19, 2011.