Check engine light - reduced engine power - what next?

Hello everyone, Sad story, I'm looking for help. My 987.2S started acting weird since the cold winter in Chicago. First it started getting longer on startups, needed 5 - 8 cranks. Then it had a reduced engine power mode once, but that went away. I used a bottle of Chevron Techron to clean the fuel lines - didn't help. I finally replaced the coils and the spark plugs and started the car for the first time in a while yesterday - it sounded strong. Today I took it for a test drive and after the perfect drive out of town (I'm pretty sure it gained power/smoothness from new spark plugs ) it started limiting throttle on the way back - with no warning. It's weird jumping in and out of symptoms. Finally I came back home and restarted the motor - bang, limited engine power and check engine light - picture. Any ideas what could be the problem? I want to fix it by myself if possible. I'm thinking throttle body or MAF sensor? Any suggestions on how to approach this? Any comments or suggestions much appreciated!

what codes ? did you use OEM coil packs, lot of horror stories about bad out of the box coils . MAF is a possibility as well

I would check the starter, voltage leaks/battery, MAF. best if you can get the codes as Mr. Bond has mentioned....

As advised I've read the code: P1026. Autozone description: Activation intake manifold flap for air stream. Regulation - short to B plus. Explanation. Short circuit condition. Probable cause. 1 - Faulty Air control valve. EDIT: I read that it could be the High Pressure Fuel Pump , which would be a weird mode of failure for a pump, over a long time in and out of symptoms, where the car behaves completely normal for longer periods of time? Maybe... But could it be something else?

The Autozone description is absolutely worthless. ANY OBD -II code above P1000 is a manufacturer specific code. What that means is the number could mean something entirely different from what the Autozone tool tells you it is. It will only be accurate if it's read with a tool that has Porsche specific codes, ie: POR2, Foxwell , Durametric and others - PIWIS obviously. I looked it up on my AllDataDIY subscription - and was surprised that the code isn't listed, but a bit of exploring told me why it isn't listed. My subscription is for a 987.2 base - which doesn't have direct injection, it uses port injection. As such it has no high-pressure-fuel-pump - so I looked it up under my Cayenne Turbo listing which does have a HPFP - and got: I would imagine if you had an AllDataDIY for your 987.2 /S - much the same description might apply. It is very likely you have a failing HPFP ($$$$). Your symptoms match this failure. I know in the Cayenne world the "rebuilt" ones from eBay and places like that are often faulty, so this is a case where it's probably worthwhile to spring for an OE one, or at least one from a reputable aftermarket vendor, and avoid the ones from auction sites. You might also consider if you want to continue doing DIY - even just diagnostics - an AllDataDIY subscription is very worthwhile, as is a decent diagnostics tool. The Foxwell NT530 has excellent diagnostics for the 987 series when equipped with the Porsche module. Cost is around $160. AllData is around $18/year (cheaper for multiyear and multivehicle.) Before spending the $$$$ on replacing the HPFP - you really do want to assure yourself that's the problem, since it's an expensive repair. Also as is mentioned in the trouble code readout - before pointing at the HPFP, make certain the low-pressure feed to the pump is OK. There is the chance that the low-pressure pump isn't producing the fuel pressure required for the HPFP to work as it should. I'd suggest seeking out a professional and having them diagnose the issue, and not rely on an internet diagnosis - for all you know I may be a raging baboon hiding behind a computer screen.. Good luck!

Well said deilenberger, a very level headed approach to the problem, I appreciate your comment. I will invest in the Foxwell NT530 sooner or later, thanks for the plug. On top of the low pressure pump, whatever you say it is, I see that on the pumps there are also sensors that can go. It is worth diagnosing the problem with a professional, so I am planning to take the car to a well established Porsche mechanic around the Chicago area. I saw a protocol for HPFP replacement on a 997.2 - this is not the kind of job that I want to do. At the final stage there is a fire extinguisher involved, thank you. I see around a $2k spending if this proves right. Very interesting part to fail on a car. I prefer it to any internal part.

Old thread on 987.2 HPFP issues - 987.2 Fuel Pump Failures? When I bought my CS in 2013, the dealer replaced the HPFP (as well as the failing clutch switch) - there was no CEL or reduced power warning, but the pump was on the way out as the engine ran and sounded quite rough. No issues since then. Good luck with the fix.

I had the mechanical fuel pump slowly fail on my 997.2 . It starts with longer crank times because the High pressure bleeds off instead of holding the pressure for the next engine start. Eventually you get the check engine light.

You most likely need a HPFP. I just had the same issue and the HPFP replacement fixed it. Long crank times and reduced engine power after full throttle for 10 seconds/ brake / back on throttle. This happened multiple times at HPDE event. Possible the sensor but the HPFP is most likely. You need to take it to a shop that has the factory scanner

I appreciate the comments! Very interesting, so this is why the long startups at the beginning. I mean the code and the symptoms really start making sense to me now. To make things more dramatic, I am just about to move from Chicago, IL to Houston, TX this month, and I won't be able to fix the car for the next 2 months, because of staying remote. I will be contemplating this situation until I put the car at a mechanic around Houston area in August, any recommendations for Porsche specialists there would be appreciated! I can tell you that after 20k miles behind the wheel of this car, I came to conclusion that I can be buried in it. I will keep this thing turning at the highest level with no measures spared for now.

The "Houston Area" is not like most city areas. It sprawls. Like for 100 miles. Galveston, to the south, is the Houston area, but so is Conroe up north of town. Regardless, this place has great reviews and although NOT convenient for myself, I would want someone like these guys to be the ones messing with my 987 European Auto Techniks Full Service Porsche, BMW, Audi and Mercedes Benz service and repair shop www.etechniks.com Welcome to Texas. Everyone else is on the way too, so grab your spot and make your claim. Sent from my SM-G988U using Tapatalk

@up - I really like the place - European Auto Techniks, thanks for sharing! Isn't it funny that everyone left to Texas? They also took all the moving equipment, a Uhaul truck here in Chicago costs a minimum $2500 to get there. I will be near the medical center, which is one of the biggest hospital complexes in the US itself. What can I say, me and my cars are excited for the weather!

If you are near Chicago there is a great shop about 1 hour away, it is right next to LN Engineering , I had my PDK service done added the PDK cooler larger pan, shop is called Speed and Suspension.

One way or another, The Medical Center (what we natives have always called it) has provided shelter and put food on the table most of my life. In fact, I was transported to Herman Hospital in 1981 and met the future mother of our children when she unwittingly showed up for her 11pm-7am shift on the neuro ward. It's an amazing complex. In so many ways. Again, welcome to where everyone seems to be headed. Sent from my SM-G988U using Tapatalk

Boys and girls, The time has come. I did go to Auto Techniks thanks to you @snakebitten ! Michael is fantastic, what can I say, being a specialist is one thing, being a good chap is another. And now - here you go. This is where the freaking HPFP is!!! Yes, yes, it's engine out. Christ... The new pump flew in from Atlanta. Artist in me wants to see new headers here. New pump in place Now, the surprise - front engine mount went home too! I would never know that it looks this way, interesting design. Luckily, the part was in Cali and it's already on the way here. Picking up the car this week, interested to see how it drives and handles now, I will keep you posted.

WTH?? Wonder what the thinking was with placing it there. Anyone know if the 981 's is in such a precarious place?

Ok, in this episode I have some good, and some bad. First of all, the car flies. The normal startup sequence is back, no more limp mode, power is happening like it used to. Secondly, I received the car with a code: I am shuttered financially now, so I didn't speak with Mike (the mechanic) about it, he said that he just cleared the service code, which was calling for an oil change. But when I entered the car for the first time - this is what I saw. The beams work just fine, I don't see an issue here. But the code is persistent for the 4th day straight. Any input will be much appreciated.

That could be no more serious than the replacement of the headlight auto-leveling module. On my 987 I think it was about $40. It's just a black plastic box with a lever attached to the rear suspension. Based on how much the suspension is compressed or not when you start the car, it sends the data necessary to level the headlights . On my car it is approached through the driver's side rear wheel well. The far away picture has a couple of color dots to show the location. The closeup is the module/lever itself. Sent from my SM-G988U using Tapatalk

Good man, thank you for this, I will investigate according to your instructions.

It might just be disconnected.. I believe it has to be disconnected for engine removal.

That's probably very likely, if you think about it. Good call. Sent from my SM-G988U using Tapatalk

Story time. I go behind the left wheel, as recommended, and you guys are absolutely right: Mike, when I told him, wanted to drive to my car and provide the service without me doing anything, then when I appeared in his shop, he apologized in the most sincere way. I told him that I completely understand, I am in the medical field, worse things happen, it's about how we deal with them. Long story short - they reconnected the module and the car not only flies (as it did before) but is worry free now. This 987.2S is a great car and I'm planning to keep it for a long time. I have a list of things which I want to do to it to make it look sharp and fresh (including new PSS9 shocks and respray/ceramic coating). I will keep posting as the time comes. Again, thanks to you guys and cheers!

Glad it was helpful - one of those BTDT, but I realized it almost immediately.. (years and years of DIY..)

I have a similar problem on my 2013 Boxster S 981 , on cold starts i have to start 5-10 times. I've already replaced almost all air-parts ( AOS , MAP, ...) , cleaned everything, no avail. Now i'm thinking the problem has to be the fuel ... either the fuel pump relay, fuel pump or HPFP .... i'm really hoping it's not the latter @Boski : did the new HPFP solve your issue ?

Yes, it did. Completely. The car flies. When it started happening, I also replaced all spark plugs and coils thinking that it would solve the problem. Maybe try a techron chevron to clean the fuel lines, I did that too. But then I've read the code and found out that many 9A1 engines were recalled for HPFP. Before, if the car didn't go to limp mode, I had a subtle "choking" sensation around 2k rpm at full throttle, not sure if this is pathognomonic. This is gone too. It shouldn't leave you stranded anytime soon, but it probably won't get any better.