Engine Cranks But Wont Start

[Motorhead]

Nick,

I suspect that it (and the DME module itself?) will be located somewhere on the engine side of the rear bulkhead, but can’t confirm.

If you want to search through the (rather lengthy) PET for your 987.1 to get some ideas you can download it from here:

https://www.porsche.com/uk/accessoriesandservice/classic/genuineparts/originalpartscatalogue/

The DME controls the ignition and fuelling and since the fuse that keeps blowing is associated with both then clearly there’s a problem in that part of the circuitry, but without detailed diagnostics it’s impossible to say what’s actually causing it.

All very frustrating for you … but full marks for sticking with it!

Jeff

 

[Nick7602]

Hi Jeff

Its a process of elimination, my thinking is if I can help the techie by ruling out certain parts, like the DME relay he can crack on checking things like coil packs etc, and injector connections.

I don't like giving up as thats to easy, prefer to learn and understand the car then place my experience on the Forum to help others hopefully, its all a learning curve albeit an expensive one

Kind Regards

Nick

 

[Motorhead]

I know where you’re coming from Nick … I’m the same! []

I’m not sure if it helps but here’s a link which shows what you’re looking for, though I’m not sure where it’s located:

https://www.design911.co.uk/fu/prod12484/DME-Relay-Porsche-Boxster---Cayman---997/

Jeff

 

[Motorhead]

Nick,

Looking at the PET for your car the DME is shown as item 1 in Illustration: 901-003 and the DME relay as item 7 in Illustration: 902-000 (part no. 999 657 013 90) with relay location/code no. S11, whatever that means! Maybe you can have a look around to see if you can recognise some of the plastic support structure?

Happy hunting!

Jeff

 

[doktorbone]

You have got me wondering where the relay is in my car now

Found this and now I know ..

https://howtoporsche.com/cayman/987c-2005-2013/2005-to-2013-cayman-987c-fuses-box-diagram-location-amperages-list/

Hope all goes well getting yours sorted Nick.

Cheers - Tony

 

[Nick7602]

Hi Tony

Thank you for your kind, thought, Jeff very kindly showed me the fuse diagram earlier in the thread

Thanks you for your kind thought though Tony

Nick

 

[Nick7602]

Nick,

Looking at the PET for your car the DME is shown as item 1 in Illustration: 901-003 and the DME relay as item 7 in Illustration: 902-000 (part no. 999 657 013 90) with relay location/code no. S11, whatever that means! Maybe you can have a look around to see if you can recognise some of the plastic support structure?

Happy hunting!

Jeff

Thank You Jeff

You and the guys have been very helpful, with your help I now know where the relay lies under the steering column to the right,

Great now I can crack on and install, the relay once I get it

Thank you lads for all you kind support

Nick

 

[Nick7602]

Well we have now found the problem

Coil Pack 2 has literally melted on to the wiring loom plug, the looms plug has got to be cut off and replaced, my techie chap is in the process of changing all the coil packs and wiring loom plug

 

[Motorhead]

Wow! A mega-short there Nick. Hopefully your tech will sort it and get you back on the road again.

Jeff

 

[Nick7602]

Hi Jeff,

This is what happens when people skip on parts at service time

I know the previous owners haven't been that diligent, skipping on replacing stuff, thank fully Im not like that, I will post some pics of the parts when I see the Tech

These coil packs are a problem to alot of car companies, im surprised no one has made a better quality version.

Nick

 

[doktorbone]

Great news on a quick diagnosis Nick - that is a proper short!

Hope you can get it resolved with a minimum of hassle, with a full set of new coil packs you should be good to go.

Would be very interested to see pics of the carnage.

Cheers - Tony

 

[Motorhead]

You’re right Nick. Now that the older cars are more affordable they can fall into unsympathetic hands, with owners either unable or unwilling to spend money on correct servicing and maintenance. Thankfully that’s not the case with yours and it sounds as though you’re committed to sorting out previous neglect … full marks for that!

Jeff

 

[Nick7602]

Hi Guys

I certainly hope so Tony

I think Jeff that if you decide to buy a Porsche you buy it for one of two reasons, 1, Its ok I will thrash the living daylights out of it and junk it when its starts to cost, because it was only cheap after all.

2, You love the Marque, and are committed to replacing worn broken and badly maintained parts, for the love of the car and the Marque.

I have to say 2 is where Iam, I decided long ago not to give up, there have been times I have torn my hair out trying to understand the mentality of why previous owners haven't looked after the car correctly, however with the brilliant help of a well recognised Porsche Specialist, I am in the process of replacing a shed load of chassis components, even the Specialist is amazed at the level of replacement Im undertaking.......I just love Porsches

 

[Nick7602]

[/img]

Hi Guys

Here is pics of the carnage,

So: symptoms were 1, smell of burning a few weeks ago I dismissed this to a bit of over velous driving on my part. 2, Car idling on the drive for about 30 mins a sudden rise in revs slightly for a brief moment. 3, Car pulled of the drive car coughed and buffeted then completely cut out. 4, Car would crank but no start.

Result: Melted coil pack see pics, this need to be cut off the plug, and a new plug fitted to the wiring loom.

There is a lesson here I think, if something needs to be changed at service time such as coil packs and plugs then do it, the manufacturer has worked out the correct interval time for various components to be replaced, Porsche will have worked out how many hours it takes for these coil packs to fail, and then worked on the side of caution and built a safety margin in, so when they need replacing replace them, the poor previous owners lack of mechanical sympathy and care has led to this failure in my opinion.

[/img]

[/img]

 

[doktorbone]

That looks nasty, could have been a lot worse - think you had a lucky escape there Nick []

Even with full service histories, we never really know if things have been replaced when they should have been by previous owners.

I'm with you 100% on adopting a "preventative" outlook regarding replacements/maintenance on our cars, gives you a good feeling knowing that with a bit of luck there should be no surprises (I am touching wood while saying that!)

Hope you are trouble free from now on.

Cheers - Tony

 

[Nick7602]

Hi Tony

Im sure there will be other surprises, at least I now know all the coil packs have been replaced, and to be honest the car drives a lot better, so im quite pleased, yes I think I was quite lucky, I hope my experience helps others within the club

Kindest Regards to all that read my thread

Nick

 

[Boxstercol]

Wow! Scary stuff, could have been a lot worse...

Glad you got it sorted.

 

[JohnCRS]

I think the two most common causes of electrical gremlins on our cars is coil packs and batteries. The former are very exposed on the boxer layout and the batteries are not that great as fitted, especially in low mileage cars.

Good to see the successful solution.

John

 

[Nick7602]

I think the two most common causes of electrical gremlins on our cars is coil packs and batteries. The former are very exposed on the boxer layout and the batteries are not that great as fitted, especially in low mileage cars.

Good to see the successful solution.

John

I Must apologise John for the late reply, been ill for a few days

Yes I agree, the coil pack concern is well documented, and appears to be across alot of Marques not just Porsche which I find very odd, you would think that perhaps by now the various manufacturers would have found a more stable coil pack that is robust, but then that wouldn't keep the supply chain happy would it?

 

[Sja360]

Hey guys, i had a similar issue, glad i came across this thread so checked some of the coil pack plugs, sadly cylinder 1 is stuck so likely culprit. My coils are about 5-6 years old, although the car initially started, misfires were shown then the car died.

My car has been laid up over winter in the driveway and always sits on a ctek charger, so im guessing water got in and shorted the plug. The coil packs look good on the face of it.