issues with hot start

[Jonesy997C4S]

Alright guys,
Had my motor since aug 2014 and have had issues starting the car when the engine is hot from day one. Its under warranty and has been in 3 times. They have replaced a wiring loom which they said was dropping voltage.
Took it out for a good run today through Forrest of Bowden and had the issue starting it, it took three goes and a boot full of revs. Luckily I recorded the last 2 attempts and I also tried it again when I parked up at home, same result. At least they will see I'm not making this stuff up.

Any ideas on whats causing this.
Fyi temp gauge is reading between 90 and 100.

[Rockster]

Jonesy997C4S said:

Alright guys,
Had my motor since aug 2014 and have had issues starting the car when the engine is hot from day one. Its under warranty and has been in 3 times. They have replaced a wiring loom which they said was dropping voltage.
Took it out for a good run today through Forrest of Bowden and had the issue starting it, it took three goes and a boot full of revs. Luckily I recorded the last 2 attempts and I also tried it again when I parked up at home, same result. At least they will see I'm not making this stuff up.

Any ideas on whats causing this.
Fyi temp gauge is reading between 90 and 100.

Your post is short on details.

If the engine cranks slowly then starts this is almost always a voltage/current supply problem. Bad wiring between the battery and the rest of the car has to be suspect.

One way to test this is to turn the key on and start or try to start the engine. Turn the key off. Raise the car and check the wiring that carries electricity from the battery to the other areas of the car, the alternator, starter, etc. Be careful. In some cases the bad wiring can glow red with heat. Even if the insulation is intact the wire/cable can be hot.

In the case of a hot engine this is going to be a test of little value as of course everything is already pretty hot. You might be able to use a hand held thermometer gun to without having to touch anything measure the temperature of various items, and battery and other large electrical cables specifically. You are looking for a length of cabling that is really hot compared to the other things around it.

If the engine cranks at normal speed but just doesn't fire, and there are no attempts to fire with back fires, spit backs etc., this suggests a vital sensor is not working. The engine controller does not get a signal it needs and thus does not enable fuel or spark. The engine cranks just fine it just doesn't start. There will be no CEL because emissions are not affected.

The most common sensor to fail is the crankshaft position sensor. That this occurs when the car (and sensor) is hot makes some sense.

With a newer model of car the fuel delivery system can be suspect. Either the high pressure fuel pump (or low pressure fuel pump) is marginal and not delivering any fuel, until of course it does.

Often hard starting is accompanied by an engine that feels down on power when pushed hard but not always.

[zulash]

Jonesy997C4S said:

Alright guys,
Had my motor since aug 2014 and have had issues starting the car when the engine is hot from day one. Its under warranty and has been in 3 times. They have replaced a wiring loom which they said was dropping voltage.
Took it out for a good run today through Forrest of Bowden and had the issue starting it, it took three goes and a boot full of revs. Luckily I recorded the last 2 attempts and I also tried it again when I parked up at home, same result. At least they will see I'm not making this stuff up.

Any ideas on whats causing this.
Fyi temp gauge is reading between 90 and 100.

Hi, i've heard a lot of similar stories of 'sluggish' hot starts particularly on 997's. From what i can gather this can be a failing of the cable that runs from the alternator to the battery. I had a similar problem with the 2007 997 3.6 C2 i bought recently. However i can't help any more than this.... as i fitted a new battery and seems to be ok 'ish' since.