Ox66 will not start

[Sfrye]

It will turn over and crank for a second and then shut off. Then it will not crank again unless you let it sit for a few minutes. I have 36lb of fuel pressure from the high pressure pump. Any ideas or suggestions will help.

[McQuaig]

Mine would do that if the battery was not REALLY strong or connections weren't tight...

[javelin90]

What maintenance has been done to the motor? Any filters like vst been replaced? Was the 36psi measured when key was in the run position? Has the O2 sensor been replaced, spark plugs, link n sync?

[Sfrye]

The engine was just rebuilt. I got it to run now but it will not keep prime from the gas tank. All low pressure pumps were replaced. All filters were cleaned, brand new plugs. The 36lb of pressure is when the key is first turned before starting the engine.

[ClarkBird]

as soon as it fires, you let the key go back to "on" position and then it dies?

[javelin90]

Does it have an onboard fuel water separating filter? If it does fill the filter about 3/4 full of clean/filtered gas. If no filter check the primer bulb that sits in the splashwell.
Try a portable gas tank attached to fuel line on motor. Make sure the ground wire is attached. Recheck all your connections. Different project but I rebuilt my Yukon 5.3l motor and changed out all the AC Delco sensors. No spark. I forgot that when I replaced the AC Delco crankshaft sensor I had to use the new elec connector from ac Delco.

[Sfrye]

Little update. The engine will start if you give it gas while you try to start it. It will not idle and if it shuts off you have to wait a few minutes before it will start again. Any ideas

[javelin90]

Have you checked the lync n sync on the throttle plates?

[Sfrye]

It acts like it is getting too much fuel and flooding. When I took the air box off the front of the engine it had fuel running out the bottom of it.