Poorly 996 C4!!! Help

Hi there!!! Don't know if anyone is able to help??? I've got a 2000 996 Carrera 4 Tip. My car suddenly developed a problem. It misfired and would then simply die, almost as if it was running out of fuel. You would try to restart it and nothing. It would just turn over but not fire. Then, if you left it for 30 sec or so it would fire back up and run, enough for me to limp home basically. Bearing in mind Ive done nearly 10K miles in the past 12months and its never missed a beat, trips up and down to Scotland, no problem. Now, this all started 3 wks ago. The very next day after the initial problem I took to my local Porsche specialist and was told it was a Cam Senser??? The error codes were:- P0343 Phase senser 1 (camshaft Half-effect senser 1) P0336 RPM input circuit. I was told they would have to take the engine out in order to replace this cam sensor??? I later found out they had sheared the mounting bolt holding the sensor in place. After 'umpteen' phone calls to the garage (they only called me twice the entire time) and it becoming blatantly obviously they didn't have a clue what was wrong!!! They replaced a cam sensor and crank sensor??? Finally, after 2 WEEKS and £1032 later I eventually got the car back, assured that everything was fixed and it was running perfectly again!!! Initially all seemed good, but the very next day, I felt the car was, well, it was just lacking!!! The following morning it conked out again, exactly the same as it had before. This time I took it to another Porsche Specialist and he too run the diagnostics, again the two error codes were there, exactly the same as before!!! The car is still at the second garage (now a total of 3 weeks down the line after the initial break down). This time, this chap is telling me its something to do with the 12v supply going to the cam sensor, sometimes its running ok, then suddenly it fails??? So I'm assuming if all the wiring is ok then its perhaps a problem with the ECU itself??? Any suggestions would be greatly appreciated, if anyone knows what this is then your input would be most welcome. Also if it is the ECU an idea of where I can get the ECU repaired would be great and even a cost. One things for sure though, its totally shattered my opinion of what was previously a stunning car and its made my loose all faith in Indy Specialists, do they really know what they're doing??? Thanks for taking the time to read through, apologies for the length of the post.

From the diagnostic manual: P0343 - Camshaft Position Sensor 1 "" Above Limit Function - The signal from CMP sensor 1 identifies the first cylinder. If both the crankshaft position (reference mark) signal and the CMP sensor signal coincide, this signifies the ignition timing for cylinder 1. The recognition of cylinder 1 is necessary for the purpose of sequential fuel injection and knock control. DTC No. - Fault conditions - Fault area P0343 - Above upper limit "" Short circuit to B+ P0336 - Engine Speed Sensor Signal "" Open Circuit DTC No. - Fault conditions P0336 - No rpm signal whilst engine is running Fault area "" Corrosion in connector "" Open circuit or short circuit in wiring harness "" Rpm/crankshaft position sensor faulty "" DME control module faulty Both seem like wiring faults to me. The manual shows all the connections to check, so I expect Indy 2 will start there, if he hasn't already. A new or replacement DME is a last resort. There is a company in Dorset called Autotek Electronics who repair DMEs, or offer an exchange service, but I have no idea if they are any good. I recall someone saying they charged £400, which is about half the price of a new one. These things are notoriously difficult to track down. It sounds like Indy 1 hadn't a clue, but Indy 2 has a better handle on it. If you want the diagnostic sheets, drop me an email.

I am not sure if this is the same as you, but my 996 was going great then on the way through the town center it started to splutter as if I was out of fuel and as you say I tried to restart it and nothing, wait 30secs and it would be okay but a little while later start to splutter and I have to rev it and ride the clutch for a bit to keep her going. Anyhow, I opened the back and took apart the airbox so I could see the carb, reved it so it opened and black gunge was inside it. I used a carb clearer and with my finger managed to clean it. I took it into the garage and put a special conditioner through it, you cant buy it but most garage have it, its a purple can you add it with petrol. The problem was a bad bit of petrol and dirty carb. I need a new maf also which will make my car run like a dream again. Again not sure if this will help but it worked for me and I never ran mine on a machine for error codes but give it a try, it wont hurt and proberly would need doing.

Well, 5 weeks down the line now and Im still without my C4. Its in at a second garage now, yet still no resolution. Not even after 3 WEEKS!!!! First off it was thought it was the engine ECU, now its thought its the wiring loom??? I'm really struggling to understand to be honest, how on earth it take 9 days to only partially remove the inlet manifold (so that the relevant section of the wiring loom can be inspected).... Does it really take 9 days to do such a task??? As mentioned in my earlier post, my faith in what was my pride n joy has now totally gone and I have absolutely no respect for these indy's anymore!!! Not a single phone call from either garage explaining their progress, we've had to chase all the time. Each time we call its 'oh, I'll get onto to it tomorrow - tonight - this afternoon' WTF!!!!!!!! So much for customer service. I understand they may be busy, but seriously???? I really feel like naming n shaming!!!

You should tell us who they are, their are some good ones and bad ones like any business, but it would be nice for us to know, your not going to put them out of business but if they cant even return your calls then you should say who they are. Best of luck and it would be intresting to hear the outcome. Regards Philippe

Naming and shaming is against the forum rules these days........

............ and always has been on this forum (sadly) [8|]

I'm sorry, I didnt mean to cause an issue, I've deleted my earlier post!!!!!!!!!!!!!!!!!!!!!!!! It was obviously a little too close to the core, even though I felt it was justified. I was just venting some frustration after countless phonecalls and a fair bit of cash and hoping for some sound advice!!! Please accept my apologies!!! The problem it seems has now been resolved, finally, after 6 weeks!!! Thats the trouble when your relying on your car as your daily transport!!! The faulty part was in fact the wiring loom (engine compartment - two wires feeding the cam sensors???). I've learnt a valuable lesson here, only use properly trained Porsche people.... even if its reputed they've previously worked for a reputable Porsche 'specialist' (and now set up shop on their own) doesn't mean they are in fact suitable or indeed qualified!!!!!!!!!!!!!! Stick with fully trained Porsche folk!!! May I just add, the second garage came up trumps!!! [ ]

I don't see anything wrong with your previous post, so I have restored it. You are perfectly welcome to vent your frustration here, and the important thing is that you didn't 'name and shame'. It is a very valid point you are making. Also, there would be no problem if you were to name the second garage as a recommendation.

The second garage is Porsche Tech . He's a one man outfit so therefore patience is the key as obviously he has other customers he has to look after. Finally, after collecting the car and spending an hour with him and him explaining everything he's done I totally understand why we had to chase him, he's just too busy!!! His knowledge is unbelievable and his experience with Porsches is very extensive!!!