2007 LR3 4.4l AJV8 JAG
165KMILES
Very irritating. Starts up fine initially. Then won't start again if warmed up then turned off. Starts fine after it cools off for about 15 minutes.
Prior to a 1800 mile trip I replaced the following:
Fuel pump
Fuel filter
Injectors
Plugs
Coil packs
MAF
Both upstream O2's
Fuel rail temp sensor
Crank position sensor
Ran fine pulling another car the whole way with the exception of this restarting problem.
GAP reads fuel pressure 71.

 

I'll keep everyone up to date on progress for the purpose of future search results as this is proving to be quite the challenge.
Next step will be to start testing the replacement sensors. Have to restart at the beginning at this point. Beginning with the fuel rail temp sensor. It's only 25$so on Monday I'll replace it again.

 

Continuing the update...
Replaced the fuel temp sensor. No change. Also replaced the throttle body with its electronic module in mind and because I had an extra one.
Read a thread somewhere the starter turned out to be the problem so I'll be trying that tomorrow. Again the engine seems to crank fine just won't fire up when hot. Current starter cranking rpm is 822 as displayed by GAP.
If that doesn't do it then I'll truly be back to square one and switching the filter/regulator for a land rover oem.

 

When it wont start does it actually turn over or nothing ?

 

Turns over just fine.

 

That rules out the starter then.

 

Replaced the filter/regulator again because the problem began literally after the filter change.
No difference.
Replaced the fuel pump relay.
No difference.
That means I've replaced the following:
Fuel pump Fuel filter/regulator twice
Injectors
Coil packs
Throttle body (module)
Fuel rail temp sensor twice
Crankshaft position sensor
Fuel pump relay
There's nothing conceivably left but the starter which I theorize maybe is getting hot and malfunctioning then cooling off and performing as designed.

 

Haven't tried cam pos sensors because I know how they act when they fail because I replaced them less than 1 year ago.

 

Not necessarily. Aside from the fact that it's the only option left, I did come across one example of the same situation where the starter was the culprit.
Seems highly unlikely which is why this was focus.

 

Another update.
New starter didn't fix it.
Starter relay didn't fix it.
Also fuel pump relay didn't fix it.
Switched to another crank position sensor which didn't fix it.
I also changed one camshaft position sensor which I don't believe can cause starting issues.
I took note of the exact time after shutting off the engine in which it's impossible to restart. I was able to start the engine every 60 seconds until the 5 minute mark when it would then crank but not start.
I hope if nothing else, this thread helps SOMEONE ELSE once I get it figured out.