so i just rebilt my motor. well befor i went a rebuilt it i had probablems starting. i would hv to let the lift pump run 3 times or more in order for it to start. now that i rebult the motor i still have the some probablem i know when i took the motor out the return line on the back of the head was a lil lose but i made sure it was tight when i put it back in. i dont notice and fuel leaking anywhere so im stumped. i have a raptor 150 on my truck. what should i be running for fuel pressure. should the LP run when cranking the motor over? if so mine isint. need to get this figured out its driving me nuts!!!

 

I know if you have to much pressure it creates a hard start, fuel pressure should not be more than 22-24 PSI. If its more turn it down. The lift pump will kick on if you dont have a succesfull start. IF it not that, nore fuel filters, then possibly the injection pump.

 

Wait what did you rebuild exactly?

 

the whole motor. piston barings injectors new cam turbo manifold studded the head on o ring. 115# springs. im going to try a lower my fuel presure to 16?? see if that helps

 

16-18 pounds should be about right just keep it under 20. Yes the lp should be running while cranking if its not that could be part of the problem. How does it run once it starts?

 

i have had to wire fass pumps where they didnt pump while cranking.

 

Did you rebuild it because of the hardstarting? Or just because of performance.

 

performance. so should the LP run while cranking?? i adj the press to 17 17.5 and still hard start. runs fine after it starts but i have to run the lp 2-3 times befor it will start

 

The Factory LP runs 25-30 sec at first turn of key and should also run while you'er starting the engine.

 

is there a way i can get my raptor 150 to run while cranking? like put a switch on it?