why wont my 7.4L start right away

[clownracer]

engine is out of a 1992 suburban best as i can guess its a TBI engine with new dist cap, rotor, coil, wires, plugs, fuel filter, k/n airl filter

i will switch the key to run and let the fuel pump prime but it still takes at least 7-10 cranks to start up chugga chugga chugga chugga
it seems like forever

engine is swapped into a 1994 GMC Yukon i am unsure if it has the correct fuel pump but i am also unsure if that would matter? what else should i be checking?

 

[clownracer]

noone???

 

[JKmotorsports]

Have you checked fuel pressure? Does it take a while to build up?

 

[clownracer]

no thats going to be my next step....is hard starting usually fuel related?

 

[JKmotorsports]

Low fuel pressure can cause hard starts. How does it run once it's started? Fuel pressure on TBI motors should be 9-13psi and is the same for the 454, 350, and 305.
What do you know for sure about the motor? Did you buy it the way it is or did you add the new parts yourself?

 

[clownracer]

today i checked the fuel pressure pump will prime to 13psi then immediately drop to zero it is not holding pressure at all....running its 13psi but i cant test it under load

warm starts are easy one crank cold starts its chugga chugga chugga till it decides it wants to start

is this the pump or is there another part that will hold pressure to start

 

[SC88]

today i checked the fuel pressure pump will prime to 13psi then immediately drop to zero it is not holding pressure at all....running its 13psi but i cant test it under load

warm starts are easy one crank cold starts its chugga chugga chugga till it decides it wants to start

is this the pump or is there another part that will hold pressure to start

Could be:

Leaky injector
Bad Regulator
Bad Pump
External leak

I would start at the engine and work your way back to the tank.

 

[clownracer]

ordered my new fuel pressure reg ill report back