I have a 2000 acura rl when it sits for a while it dosent want to start right up unless I turn the key not to start an wait five second when start it an then it starts right up what could that b

check to see if your fuel pressure holds. put a guage on it and watch it over a period of time.

what's happening is you are not allowing the fuel rail to pressurize....and starting it before any pressure can accumulate in the fuel rail...so yes switch it to the on position for a few maybe 5-7 seconds then engage the starter motor~

you could change the inline fuel filter...that will help to make the fuel flow faster~

you shouldnt have to do that once you turn the key on it should pressurize it enough to start. unless it has lost to much pressure and it takes longer to pressurize the rail.

good point 'bro~, could it be a leaking injector?....excess fuel goes through the loop, so must be the fuel pressure regulator?

could be either indeed.

I changed. The regulator didn't. Work

if this is the only problem, change the fuel filter, if the problem continues would look at the fuel tank and pump~

Thatz next I changed that filter

still insufficient pressure....would look to a weak fuel pump~...or sludged up...opening the tank we can see if any tropical fish were put in there by mistake~