1992 Mercury Topaz vapor lock

[rottendave]

I have a merc topaz 96, v6 and when its been running for about an hour it shuts down on hot days. it has fuel injection my mech said might be vapor lock and have to wait an hour in shade to start up again. im an old veteran and live in the Mojave desert gets hot when waiting for it to cool down. can it be anything other than vapor lock??

[carriedi]

could be vapor lock. if you have a fuel pressure gauge with an exhaust port you could look for air in the fuel system when the problem occurs. Fuel pump relay, EEC relay, fuel pump, a shorting injector, fuel pressure regulator to high, coolant temp switch open - reading way too cold, fuel pressure regulator leaking into vacuum port...

you will need to check for spark, check fuel pressure and fuel injector pulse when the vehicle won't start. If you have spark, fuel pressure and pulse when it won't start that's when you would look at the volume and quality of the fuel stream (see if there are a lot of bubbles of air in the fuel stream)