Im having an issue with my turbo. I was out driving and popped home for a minute and when i went to drive my car again it was boggy and missing, i turned it off in my car elevator then when i tried to start it, it hardly ran for a min and i got two feet and it stalled and then wouldnt start at all just turning over.

I am getting an error for all 6 injectors "fuel injector, Value below lower limit value" it wouldnt make sense to have all 6 fail at once and for the harness to be toast or have a break then it would be "no communication" i am pretty sure.

I have checked the fuel pump relay and fuses and changed the fuel pump even though its odd for it to just go like that considering there are two.

I have had my tuner tell me to set it back to its factory tune to see if its a immobilizer issue, but nope still tuning over and over.

any ideas ?

 

I had a similar thing happen when one of the turbo hoses pop off. When you were out driving before this happened, were you on full boost at any time?

 

Most likely i had it running full boost, ill be fery pissed off if that is what it is, but unlikely if im getting 6 codes and they are all for injector circuit low.

 

Based on your description it sounds like you've got an electrical issue in that all six injectors simultaneously gave an error. Have you verified that your alternator is outputting the correct voltage and does the battery appear to be low?

If I were troubleshooting this car I would put a fresh battery in it and see if the car starts. If not, I would start troubleshooting in the following order:

An engine needs three things to start: Fuel, spark, and air. Since the car was sputtering and bogging before it refused to start again, that sounds like a fuel delivery issue. Since you changed the pumps you can rule that out. Have you checked the voltage going to the fuel pump to make sure it's getting 12VDC? If it is, check the voltage to the injectors. The easiest way to do this is to probe the voltage output from the PCM. If you are getting 12VDC to the injectors out of the PCM, then you'll want to turn your attention to the ignition or make sure you are getting air to the engine. Again, since you're getting trouble codes for the injectors I would focus on the voltage going to your fuel pumps and injectors, and if that checks out you may want to have your PCM checked out.

Hope you get it sorted out.

 

Thank you very much for the input ! A great deal of help there, I'll check into these things along with some other electrical my tuner has suggested to me.

Such a pain in the butt as it just happened out of nowhere.

Ill post once once I have some results or get somewhere with it.

As for starting, I had the battery jumped with a power pack with 2000 watts and 900 cca to assist it and no go.

Not sure how to check the alternator on this car and it will also be hard to check the output if it's not running.
Had a few dead batteries in the past few years as the car sits for a while as I work overseas 7 months of the year. Hopefully this has nothing to do with it.

Cheers and again thank you for your input.

 

Glad to help. An easy way to check to see if the alternator is working requires that the car is running unfortunately. If the car won't start you'll need to remove it from the car and have it load tested. At this point, the alternator is not your issue because it has no influence over the engine starting.

I was thinking about this and, I'm not sure about it but it's something quick and easy to check, try taking a look to see if anything in the fusebox is marked DME. It could something as simple as a blown fuse and the DME not getting power. If you have a 997.1 I think the DME fuse is located in position D5. It's a longshot but it may be worth checking out.

If that's not it you'll need to troubleshoot voltage to the injectors, pumps, coils, etc.

 

I have found some odd things going on. firstly im getting 8.4V on the pumps at the fuse and 10.4v at the 7.5 amp fuse next to the two fuel pump fuses when I pull this 7.5amp fuse the fans up front turn on full bore (DME control unit) . . also blowing 15amp ignition coil fuses one after another. At position D7 I think. so i have a wiring issue somewhere. now to try and track it down. I had a Porsche tech ask me if I smelled a burning wire smell in my car when I had it in for a cam solenoid issue, anyways I didn't smell it and he didn't try and find where it was coming from. So I may have something inside the car damaged (odd but possible )
now need to locate the harness that heads back to the engine bay.. i kinda feel the connector for those functions is possibly damaged or something.

should I be getting a full 12+ volts at each of these fuses when removed ?

 

1 year ago i faced same issue on my friend's car,it was a bad ignition coil.remove all ignition coils connectors and replace the blown fuse,then start to connect one after one to see which one has a short circuit.

 

Same issue of no start as well ? Just cranking and getting a fuel injector below lower limit code ? Or just the popping of the coil fuse ? I have erratic voltage on fuses, I'm not sure a shorted coil would do this. Any coil I've seen fail went to open and the car missed, seen hundreds on nissans, vw and Audi.

 

no start and blown fuse caused by shorted coil but cant remember fault codes.

 

Glad to hear you're making some headway here.

It's been my experience that electrical issues can manifest in all kinds of weird ways. It's entirely possible that you do have a coil issue and it is causing voltage issues on other circuits via a common ground point. I'm not familiar with how the 997tt is wired but it's not unusual to isolate the injectors and coils because they are two of the noisiest components in the engine from an electrical perspective.

Injectors are essentially solenoids, they are either open or closed and they tend not to cause erratic issues like you are describing. Additionally, I would be hard pressed to believe that your wiring harness spontaneously combusted for no particular reason. What I can believe is that an internally shorted coil may be backfeeding noise and voltage into the system causing regulated voltage outputs and equipment on a common ground to malfunction. I could be wrong, but chasing a bad coil may not be a bad idea...especially given the reputation of Porsche coils. In fact, given your description of the problem the coil theory makes the most sense.

Please keep us posted.

 

Sounds like you have a short and whoever the dealer was that fixed you cam solenoid knows it was an issue but was to lazy to track it down.

If you have 12v shorting to ground you won't be able to see if the is anything else wrong until you fix the short. You will chase random electrical issues until you get frustrated and sell the car.

 

Thank for the posts fellas ! really appreciate it !

its helped me bark in the right direction to find the coil fuse blowing instantly telling me there is a wiring issue (not as likely as a coil issue) This would make sense as when the issue happened i had just had a car wash and drove around a bit.

Toronto uses a lot of salt on the roads and my car sits for 4 plus weeks when im over seas every other month. The porsche coils are known to crack and cause issues and when i had my engine out I replaced my coils with (performance high output coils) lol from a reputable aftermarket, but they looked like repotted factory ones that may have been reworked for higher discharge (possibly quickening the issue of the coil jackets failing)

this is my hypothesis after following all of what has been said here and Rennlist minus a few things that are unlikely as the car will not start and ive had a good source of power going to it to try and start the car and still no go.

After seeing the dropped voltage to the fuel pumps and no pressure at the fuel pumps its telling me they are getting not enough voltage to prime up even though i hear stuff going on up front, its not the sound of a fuel pump priming.
I have changed the fuel pump, I have reflashed to factory tune to eliminate possible but unlikely immobiliser issue.

so here we are at the coil possibly shorting out and back feeding the circuit with voltage causing all of the erratic problems and this would likely have the effect of the bogging and misfiring i had in the minute before the car died. The car ran like a champ just before the carwash, then after the carwash to my house, switched off then 15min later the car ran like dirt and stalled and didnt go again.. now we have the 15amp coil fuse popping instantly when i put it in and turn the key and injector below lower value limit (meaning none of them are cycling) and all 6 are unlikely to go at once.

ive seen this type of thing in other sensors before jsut never a coil, usually a coil goes dead and you get a misfire, but i have been told by 3 or 4 different people that its a strong possibility and given the symptoms i cannot disagree. ive just ordered 6 coils (updated beru ones because of the cracking issue) and now trying to get my god damn car out of my parking garage lol so i can get it towed to my mechanic to swap the coils as i cannot do it here in my condo parking as ive already gotten a $500 fine for "working on my car" lol (i hate car elevators and the city of toronto and their stupid bylaws)

Ill post when i get these swapped and see if it sorts the issue.. its going to be a costly hunch, but i dont know where to go from here.

 

Did you try giving it a sniff of ether to be sure it's not a fuel issue.

 

Good luck on this and please keep us posted.

I'd do the same route you are (replacing the coils). If that doesn't cure it, best to let a dealer or mechanic trouble shoot. Electrics in these cars can be a bit of a black magic at times.