E-boss

[thomas estey]

i have a mustang 5.0 with Cleveland 2v heads on it everything bolted on it the intake that its suppose to have forged pistons (domed) built for the motor with the heads a holly 650 double pumper high performance cam push rods high flow water pump and oil pump. i have spark it will fire up but will not run for long only about 20 seconds.??? i dont know what it could be?

[97Bird]

You say you have spark but how about fuel? Have you checked the fuel pressure? Check your fuel filter to see if it is plugged.