Boxster 986 - will not start - tried everything Please Help

[ro55a]

Hi there,
Am really running out of ideas and really would appreciate some help!
I have a 2000 model 2.7 Porsche Boxster 986 with manual gearbox - UK RHD model.

So two weeks ago went to start the car after a 60 mile drive and a 4 hour break after the drive.
Turned ignition - car cranks over fine but will not fire. Have tried several times since and exactly the same.
Tried to bump start and also via jump leads and nothing.
No dash lights and my MAC diagnostic showed no faults.

Details:
Battery 85 AH and a few months old - have kept charged since not being able to start and whilst trying ideas. Also tried another battery and exactly the same - no joy starting.
Fuel is at 1/2 tank and Esso 96 RON which I have used with the car for 13 years or so with no issues.
Have checked all the associated fuses and none are blown.
Have replaced the fuel pump relay - still no joy
Have replaced the fuel pump with a good /tested second hand unit from a trusted source - still no joy.
Have changed the DME relay found in the rear of the car - no joy.
Changed the ignition switch with an OEM part 12 months previous - so all good.
Have changed the Crank position sensor - still no joy.
Have removed the immobiliser under the passenger seat - perfect condition - carefully looked inside and absolutely no water ingress, terminals great and changed the fuse as a matter of course - still no joy.
Have opened the shrader valve on the fuel line - no fuel comes out and there is no release of pressure. Cranked the car over and still no fuel comes out of valve even when opened.

Am going to change the MAF tomorrow morning and the fuel filter as a matter of course. At that point I am completely at a loss. Have checked countless forums which cover all of the above - assuming MAF makes no difference ( which I don't think it will) and change filter, which was done a year ago, I am at the point where I have run out of ideas.
Let me know your thoughts please - cheers in anticipation of any advice.

[LennyM1984]

Sounds like a tough one. Why don't you ask on boxa.Net or possibly admit defeat and have it flatbedded to a specialist?

[Matt_E_Mulsion]

Is the fuel pump an in tank pump? Is it actually buzzing trying to build fuel pressure?

[V8fan]

Is there an in-line fuel filter in the system? It may be blocked.

[DRH986]

Is your diagnostic tool Porsche specific? My Son's early 986S showed no fault codes on both the breakdown recovery guy's and local garage's diagnostic testers but my Durametric showed the crank position sensor was defective.

I see you've changed the CPS so I'm not saying that's the problem, only that some fault codes appear to be Porsche specific.

[Mogul]

Have you tried it with the spare key (just to eliminate a key fault)?

[A1VDY]

Mogul said:

Have you tried it with the spare key (just to eliminate a key fault)?

This
It may also be a transponder ring fault. This picks up on the chip in the key. It's located around the ignition barrel and attached with a small screw.
Check out this first before replacing anymore parts..

[ro55a]

Thanks guys for all of the advice so far.

The diagnostic check with the MAC tool I agree could be unreliable, however I checked with an OBD 2 system this morning and still no faults? May have to contact a specialist and plug into a Porsche specific unit.

Have also swapped out the MAF this morning and nothing.

Fuel filter is not in tank and have ordered new - will fit when it arrives.

Have tried the spare key - and ignition is only circa 12 months old and still no joy.

Will let you know how I get on.
Cheers

[LennyM1984]

It does sound a bit like an immobiliser fault if everything else lights up

[DRH986]

A generic OBD2 reader won't read all the codes.

Might be worth posting on Boxa.net and asking if anyone near you has a Durametric Professional or similar.

Edited by DRH986 on Sunday 29th December 12:20

[Matt_E_Mulsion]

Matt_E_Mulsion said:

Is the fuel pump an in tank pump? Is it actually buzzing trying to build fuel pressure?

???

[glencooley]

If it’s cranking just keep going.

It will fire, mine does the same but or short start then stop trips.

The most common reason is that the battery lead is screwed.

It’s a pain to sort because it runs from the front to the middle through the bulkhead/firewall

I’d check the terminal resistance at different temps and I bet it drops the hotter it gets.

[ooid]

I had a very similar problem back in 2015. Same car, 2000 986, 2.7. My indie diagnosed the fault with the DME control unit (the ECU) and swapped with a refurbished one (same 2000 car, ebay lol). They did all the re-coding and etc, not sure about the details but after a few days of tweaking it was back to normal. I sold the older ECU on ebay a few days later, the buyer was having a similar issue I guess it was sort of common?

[TROOPER88]

What area are you op?

[ro55a]

Thanks for the additional comments chaps - very much appreciated. The fuel filter arrived this evening so that is next to fit - I will then need to double check that the replacement and used fuel pump is functioning correctly. If still stuck then will look at power and also ECU as suggested.
Am based in Kent near Sevenoaks btw.
Cheers

[Escy]

The fact there is no fuel pressure is the problem.

On the ecu plug D (plug that runs into the car loom, not into the engine bay), pin 10 which is yellow / white is the trigger wire for the fuel pump relay. The ecu grounds this to run the fuel pump. The relay is in the side of the boot. Probably easiest to test here, check the ecu is grounding this wire while cranking, if it's not it could be an internal fault on the ecu. Also, with the ignition on you can ground this pin yourself to test the fuel pump (if the pump runs, try starting it up).

[Escy]

Update?

[ro55a]

So......going round in circles and decided to check the pump again this morning. The wires going from the pump to sender had come loose where I had not pushed them on properly in the first place! Started on the button.
What a dick!
Seems the CPS was the actual culprit in the end.
Thanks for the advice guys - much appreciated.

[jakesmith]

Great result and it would seem that you have replaced most of the car too in the process so I guess that's a positive!

[s3 akr]

You're not alone - spent a few days working under my car to resolve a knocking on the rear suspension. Removed, cleaned and refitted most of it, replaced an exhaust hanger, fixed a loose heat shield, had the brakes apart and still it rattled. Turned out to be the jack rattling in its storage slot in the boot near the rear wheel arch !!!!