Hard to start when hot

hey all, I have a 2007 ranger, 200,000Km, for a while now after the truck has warmed up, and then sat off for more than 5 mins to a couple hours, untill its fully cold, will have to crank for about 5 seconds before it starts.

ive been reading the forum and seems like nobody else has quite the same issue.

changed the coil pack with msd unit, changed ect sensor, changed air filter, changed fuel filter, changed plugs and wires, changed cps, tried turning the key on for a few seconds to 30 seconds to charge up. all with no change in cranking time. most times after cranking, it smells like un burnt fuel. so I'm thinking maybe dirty injectors leaking down into intake when its sitting, and causing it to act like its flooded?

I'm going to run seafoam through the oil and gas tank pretty soon and hopefully that will help. i have always run fuel system cleaner through it every 3 months.

any thoughts or suggestions would be greatly appreciated

tj

I would do a couple of tests before spending any more $$ on it.

Hook up a spark tester(old spark plug with wide gap ) and have someone crank the warmed up engine while you watch for the spark, crank until engine starts.
If spark is delayed, no spark, then it could be a CKP(crank position) sensor issue.
The CKP sensor is behind the crankshaft pulley, it has 2 wires, this sensor "tells" the computer that the crank is turning so it should turn on the spark and fuel injectors.
This sensor can be tested with a meter, they rarely fail, usually a wiring issue, which also can be tested.

If you have spark as soon as the crank starts turning, then stop cranking.

Get a spray can of Starting Fluid(ether), handy stuff to have, remove air cleaner and spray some into intake, crank engine, if it fires right up then fuel delivery is the issue.
Injectors are timed by the CPS(cam position sensor)/Cam Syncronizer, the 3.0l syncronizers have been known to have problems, not sure on the 2007s but old models should have them changed every 80-100k miles

Good read here on the 3.0l CPS
http://www.therangerstation.com/tech_library/camshaft_position_sensor.html

Flooding on a warm engine when it sits can happen but usually extra fuel will evaporate pretty fast when in contact with the warm metal parts of the intake and valves.
You can rent Fuel system pressure testers, some auto parts stores loan them out, testing the pressure with engine running and then making sure pressure stays up after shut down would tell you if you have a bad injector(leaking), or if check valve on fuel pump was bad, leaking pressure back into fuel tank.

So basically find out if it is spark or fuel that is causing the delay in starting, then go from there.
You could also have a computer issue, when it gets warm it is not waking up right away, to start the spark and the fuel.
I would read the codes(warmed up) and see if computer is responding correctly.

And just FYI, you would turn the key on and listen for the fuel pump to prime the system, the pump would be on for only 2 seconds, then turn key off, repeat the on, wait, off 3 times, then try to start engine.
Leaving key on for 10-30 seconds won't do anything extra as far as the fuel system, you must turn it off and then on again to reprime.