96 SS #949 6-sp, problems starting and stalling. Over last few weeks car has been dieing randomly when driving, no pattern, sometimes at stop and sometimes while driving, always started back up and kept driving. Now it is not starting, or when it does start its a very rough idle until it stalls, usally 10 - 15 seconds, then cranks but no start? I hear the fuel pump each time, have fuel at the schader valve. replaced fuel pump 3 months ago along with new fuel filter, fuel pump relay and fuel pressure regulator, new spark plugs, was running great?

 

How many miles on your opti? When you changed your spark plugs did you check your plug wires? Any dtc codes?

 

At any point in this process have you actually measured the fuel pressure?

 

Car has 44k original miles, plug wires looked good, fuel pressure at 43, no codes.

 

What fuel pressure regulator did you use?

 

had a similar problem on my old 1995 #133 firehawk, after replacing the fuel pressure regulator it would run fine then blow up the regulator again and again, come to find out it was the little vent on the gastank lines, you know the one thats just sitting into a bracket inbetween the rear end and gas tank? cost me $12 to fix, and never had a problem again