I have a 98 Wrangler TJ 4.0. The Jeep will crank instantly and run seemingly smooth for 2 to 3 seconds. The accelerator will respond within those seconds but still shuts if. Will never run longer than 2 to 3 seconds regardless. But easy crank start . I have 50 ish lbs of fuel pressure consistently. I have put on new battery, ECU, O2 sensors, map, mass, engine coolant, crank sensors. New plugs, distributor and cap with button. There's nothing else I can think of. I hope no one else has had the time I have had over this but if you have, please please help.