sometimes after driving and shutting the car off for anywhere between 10 minutes and 4 hours the car will not start. when I crank the engine it initially runs very rough and eventually stalls. giving it more gas/ not giving it gas does not help. and after some time (usually as long as it takes to get angry, decide that it won’t start and arrange for a tow truck.) then it starts sometime later.
new fuel pump/filter a few months ago
thought it might have been the gas cap because of excessive hissing when I open the cap but that doesn’t do anything. please help
Do you smell fuel when this happens? i.e. as you would if an engine were flooded? You say giving it gas doesn’t help - have you tried holding the pedal steady to the floor while cranking? Fuel smell would indicate flooding and point to a bad fuel pressure regulator or leaky injectors (assuming fuel injection). Next time, pull the vacuum hose off of the fuel pressure regulator and check it for fuel - if there is fuel in there, replace the regulator.
If there is no sign of flooding, blow some starter fluid into the intake and see if it will fire. If so, then you likely have a problem with fuel delivery.
You can also carry an extra spark plug or a spark tester around with you. Next time it happens, hook it up and check for spark.
no fuel smell, it’s not flooding. and it fires on ether but only until it burns that starting fluid then it dies again. so assuming a 3 month old fuel filter/pump combo hasn’t gone bad already… what else in the fuel delivery system could it be?