Long cranking and turnover to start after warm. Questions about vapor lock and leaky Injectors

[MalibuMike]

My boat is a 2007 VP 5.7 Gi with the "crab" style Distributer. Recent work includes newly installed rebuilt injectors (cleaned and flow tested), new cap and rotor, newer ( about 40 hours) VP fuel pump, and new plugs. The boat start great first time whenever I take it out and the engine runs strong. When I shut it down, it becomes hard to start if it sits 10 min to 1 hour.To start it, I have to hold the key and spin the starter for about 5 to 7 seconds before it gets going. On a few occasions, I titled the throttle forward about 50 percent and that seemed to help it start quicker. I recently diagnosed a bad distributer cap, but kept the rotor since it only had about 30 hours on it. I also pressure test the high and low fuel pressure and they are in spec.
Note- The coil looks older as I see some corrosion on it.
I've read about vapor lock, leaky injectors, bad coolant sensors, and dirty IAC's but don't know where to start. It seems to be temperature related. When a fuel injected engine takes that long to crank, was it flooded or starved for fuel. Anyone have any guidance on this one?

 

[ripjmk]

It might be worth checking the fuel rail pressure decay time after shutdown see how long it takes for it to drop from 50 psi to 45 psi. It should hold pressure for quite awhile. Check it when the engine is cold and again after a 20 minute run when it is hot. Anything that allows pressure to leak could be the problem, fuel pressure regulator seat or O rings, HP fuel pump check valve or any leaky injectors.
When I had this issue it turned out to be the HP fuel pump check valve, changing the HP pump stopped the pressure decay and the hot starting issue went away.

 

[QBhoy]

Change the rotor too. 100%

 

[MalibuMike]

Change the rotor too. 100%

Changed it over the weekend and still has dot start when warm. I'll do the pressure decay test next.

 

[Scott Danforth]

are you saying the motor spins for 5-7 before she fires, or the engine turns over really really slow for 5-7 seconds before it speeds up enough to fire?

 

[alldodge]

When cranking do the injectors fire?
If not check with a NOID light

 

[MalibuMike]

are you saying the motor spins for 5-7 before she fires, or the engine turns over really really slow for 5-7 seconds before it speeds up enough to fire?

Spins for 5-7. Cranking speed and power sound normal. This weekend while out at the Channel Islands, I would push the throttle forward 25% and it seems to catch and fire up more easily. I just have to quickly bring the rpms's back down. I did clean and replaced injectors myself, have a newer OEM VP fuel pump, and operating fuel pressures ( low and high ) are in spec. Also, new Napa Echlin distributer cap and new rotor. First cold start is always crisp and easy. I have not changed spark plug wires. I did replace the temp sensor at the thermostat but have not changed the sensor on the engine that sends info to the computer.
Just talking about this brings back a memory of water skiing with my grandfather. I dont remember the type of boat, but it was a sterndrive and I recall him pushing in the button on the throttle level to take the boat out of gear and moving the throttle forward a bit to start his boat. Even the sound of the higher rev then backing it down brought back memories from 40 years ago!

 

[MalibuMike]

When cranking do the injectors fire?
If not check with a NOID light

I checked a while back with a noid light to see if any injectors weren't firing. This was before cleaning...I will check again. Is there a condition that can cause a delay in the injectors firing?

 

[alldodge]

The ECM wants to see spark before allowing injectors to fire. This normally comes from the Dizzy to the ECM. Just want to see if they are trying to fire or their not

Here is checks from manual for hard start

 

[MalibuMike]

The ECM wants to see spark before allowing injectors to fire. This normally comes from the Dizzy to the ECM. Just want to see if they are trying to fire or their not

Here is checks from manual for hard start

Thank you for this. Which manual do you recommend I purchase? I need this page and whatever book it came from!

 

[alldodge]

Mine is 7742218 and could search for it.
Its just under 19MB so unable to post here. Not sure if I could send via email, but could PM me your email and I can try

 

[Grub54891]

You could try tuning the key on, no cranking. Turn key off and back on a few times to build fuel pressure. Then start. A weak fuel pump/system may not build the pressure needed. I've done this on fuel injected cars to get them going to get them to a shop or home. Sometimes it work's sometimes it don't.

 

[QBhoy]

Spins for 5-7. Cranking speed and power sound normal. This weekend while out at the Channel Islands, I would push the throttle forward 25% and it seems to catch and fire up more easily. I just have to quickly bring the rpms's back down. I did clean and replaced injectors myself, have a newer OEM VP fuel pump, and operating fuel pressures ( low and high ) are in spec. Also, new Napa Echlin distributer cap and new rotor. First cold start is always crisp and easy. I have not changed spark plug wires. I did replace the temp sensor at the thermostat but have not changed the sensor on the engine that sends info to the computer.
Just talking about this brings back a memory of water skiing with my grandfather. I dont remember the type of boat, but it was a sterndrive and I recall him pushing in the button on the throttle level to take the boat out of gear and moving the throttle forward a bit to start his boat. Even the sound of the higher rev then backing it down brought back memories from 40 years ago!

What you have said is very typical of battery issues on a gxi or mpi engine. Despite cranking fairly healthy, if the battery is not utterly perfect, it will not have enough to fire up the engine when loaded up by cranking over. honestly, it is well worth trying another battery. such a common thing on new type engines that rely on sensors and ecu getting a strong feed. otherwise they won't even try.