I have a 91 Formula/L98 with the SLP kit that has some starting issues. When the car is cold and I turn the key the motor sounds like it has fired up but when I let go of the key it dies. After that when I turn the key it takes a few seconds of cranking for it to start. It does this all the time. Sounds like it fires up on the dime but dont run. Second try will start it but it takes a few secs and does not fire up as quick as I would like. I changed the gas filter but am still having the same problem. Any ideas?