I have an 88 z24 cav. car has 158000 miles on it and has been sitting. car would start and run for 1 or two minutes and then fail to restart unless it sts for a day or so....replaced the crank position sensor...no change...MAP....no change...fuel pressure was lack luster but in spec (about 44psi). I replaced the fuel pressure regulator and last night it ran longer then it has since I got it. that said I assumed that it was still a fuel pressure issue and put a pump in. now it tries to start but does not...HELP! any idea? Thanks

All the items you have done make sense.Unless your pig tail harness to the cps is junky(bad connection) my instinct says you may have bad coils or coil.Unless you have a injector issue or the harness for the injectors is shotty.With out me thinking real hard about it I would probably be checking your coils for resistance and or proper voltage.That would def kill it running,bad coil,or coils if both are weak.Check your battery grounds too,sometimes the simple things like this can kill it.Ok and thinking solid had the day off not all tired after trking all day as usual.

Sorry, a little confused. Last known good was before pump was replaced. Sounds like we are troubleshooting a bad pump right? The car still starts with starting fluid? Can you hear the pump running to pressurize when the key is turned?