So my friend has a new 4s, drives say 10 miles, the car is warmed up, she stops for fuel and the car then refuses to start...

A few attempts later it chucks and sounds flooded but eventually starts and the car is generally lazy to start after a few turn overs defiantly something a brand new car shouldn't do!

Once its cooled down it always starts 1st time but after a few turn overs.

The car has been at Porsche for 4 weeks and they cant figure it out... anyone like have a lucky guess as to what it could be because 2 main Porsche dealerships don't.

 

A wild uneducated guess, but something sounds fishy regarding the stopping for fuel part of the story. Could it be a leaky gas cap creating the problem? I am not a master mechanic by any means, but I think that the fuel system can be compromised if the gas cap is not sealing correctly.

Again, I wild guess on my part.

 

The stopping for fuel seems irrelevant i think, because it happens regardless of where she stops but my guess was fuel pump related or something electrical?

 

if it is a brand new car, can't you lemon it for being at the dealership for so long?
never lemoned a car, not familiar

 

easier said than done but thats what she will try

 

maybe is the power positive lead that runs from the mid-transmission point, to the starter/alternator. This connection is notorious of being flacky and the signs are exactly like that. cold start: works fine. stop and go: it sounds like you are running out of juice. even if your battery is new...

 

New DFI engines have been having HPFP prblems so that may be the culprit.

 

In the USA, PCNA (Porsche Cars North America) has a team of 'techical experts' typically in each region. They handle events such as this and determine warranty coverage in the case of major repairs (ie. engine replacements). I would expect that in the UK, Porsche has a process similar to ours. I'd have (encourage, force, suggest, etc) her dealer to contact Porsche and have her C4S examined & hopefully repaired by one of them.

 

Injectors ?
fuel line ?
starter ? - my 2008 Carrera would do something like this - get warmed up, then on a quick start attempt, it would crank forever before starting. I wonder about the starter.

 

First instinct is to say bad fuel pump, but as the car has been at the dealer for 4 weeks, it's probably not that simple. Keep us updated and good luck!

 

Depending on what state she bought the car in, 30 days is enough shop time if its less than 1 year old to make it a lemon. If they can't fix it and won't take it back, she should contact a lemon law lawyer.
I, unfortunately, had to lemon a Jag XF and was getting the run around from the service people. They were trying to fix it, but kept acting like it was all normal. I got a lawyer involved and things changed instantly - they took the car back, I got my money back and I was able to move on and buy a car that actually ran, lol.
Edit: First, it's useful to just tell the general manager of the dealership that she wants out of that car - they have the ability to do that very easily for her. If they don't, contact a lawyer.

 

I'm sure he'll be offended that you think the UK is a state unless you were thinking of Kentucky.

 

lol, didn't even look at the location... sorry.
still useful info for anyone in the u.s., i guess!

 

I would say the culprit is the starter cable as mentioned in a previous post. Mine does behave a little bit in the same way. When the cable is hot, it is not conducting electricity very well, and significant drops are seen causing the voltage to the starter to be too low for cranking the engine.

The fix is not easy and is expensive.

Yves

 

This is a known issue.
The cable from starter to battery was overcrimped at factory on sone cars. When the car has been running for a while it overheats and makes it hard to restart. Eventually the starter will go bad.
If you're under warranty it will be covered and in some cases goodwilled.
It's supposed to be an easy diagnosis by measuring voltage drop on either end.
Hope this helps