JFP in PA

The Turbo uses the Metzger design engine, which is completely different than the M96/97 engine found in all the 996's. While it does have a lay shaft, it is pressure lubricated and relatively bullet proof, as is the rest of the engine. Read up on the Metzger engine, it had a true dry sump system and a lot of other improvements over the M96/97, which is why a replacement costs north of $50K.

Try 0642

The car should hold 3.8 bar pressure when it is not running, 3.2 at engine idle. All flow measurements are with the engine off for safety reasons, plus the engine would not run well, if at all, while doing a fuel delivery test as it would be fuel starved. The regulator is vacuum operated, throttling back the fuel delivery and pressure (opening) under high vacuum signal (idle, cruise, or deceleration) and stepping up fuel delivery(closing) under low vacuum signal (open throttle for power) or during engine start. It essentially is bleeding off excess fuel to the return line when not required by the engine. If you are referring to the round plastic "turret" where the fuel supply line connects, it is just part of the fuel level sender unit, which also includes the tank vent line and fuel return line, and extends down into the tank.

That is pretty much how the system functions. You should have as much fuel delivery at the return line as at the filter. While we are on the subject, have you checked your fuel pressure regulator for being involved in the noise you hear at start up? Reason I ask is your earlier comment about the fuel pressure swinging from high to low and then building back up sounds like it could be some sort of blockage, or it could also be related to the pressure regulator opening and abruptly closing when it should not be doing that: While I hate to be throwing in more possibilities at the 11th hour, if the regulator were to "dump" the fuel rail pressure, nearly all the fuel volume would suddenly be passing into the return line, which could be the source of the sound you hear as it heads back to the tank. Unfortunately, there are very few tests to check the regulator, but one common rule of thumb is if If the operating pressure is below 35psi, or fluctuates wildly, and the fuel pump seems otherwise fine, it’s probably a good bet that the regulator is bad. If you pull off the vacuum connection and there is fuel dribbling from the nipple, the diaphragm inside has failed and the regulator must be replaced. The fuel pressure regulator could also explain why the return delivery rate is so low.

It sounds like a blockage of some sort, the return line should also be at least 850 cc in 30 seconds.

Let's start with the fuel pressure. What you are describing (I cannot see the gauge in your video) is not normal. At idle, the car should have a steady pressure reading in the 3.3 +/- 0.2 bar, or 47.9 +/- 2.9 PSIG. You are nowhere near that pressure. A second critical fuel system test for these cars is delivery, or how much fuel volume is the pump putting out. In 30 seconds, your pump should deliver at least 850 cc of fuel. With the pressure you are describing, I’d be will to bet you are nowhere near that either. Something is obstructing the fuel flow. When was the last time the fuel filter was changed, and have you pulled it and at least checked it to see if it is blocked? Yes, I felt the fuel pressure readings were askew as well. I could not seem to get consistent pressure readings in relation to key cycles... I did not jumper the relay though... Switching the key on and off should produce the same results as the jumper, correct? Secondly, were do I go about disconnecting the fuel return line in order to measure flow? I need to do this... I replaced the fuel filter about a month before these issues started occurring... Is it possible to get a bad fuel filter? It was from Pelican Parts... I suppose pulling it out and inspecting it would not hurt... I will do that when I measure fuel flow, hopefully tonight... IMO, if fuel filter is okay, it must be due to a bad fuel pump or vent valve that sits next to the fuel pump access hole...??? Thanks for your input! Believe it or not, there is even a spec for fuel pressure in these cars when they are not running: 3.8 +/- 0.2 bar; which is even higher than the idle fuel pressure. Normal method to check fuel delivery is to disconnect the fuel line under the car at the fuel filter or at the return line (which is under one of the removable panels near the front of the engine; if you have access to a Bentley manual, it has pictures) so that you can catch the fuel in a measuring container. As your problems started just after installing a new filter, I would start there. It is also possible to check fuel delivery volume at the fuel rail by disconnecting it and routing it to a line that runs to the collection container, but the under the car method works fine and does not require a special routing line to run the test. And yes, there are bad filters, right out of the box…… I would also try running the fuel pressure test with the gas cap off; yes, that may throw a “large vacuum leak” code, but I would want to see if the fuel pressure changes when the cap is removed.

Let's start with the fuel pressure. What you are describing (I cannot see the gauge in your video) is not normal. At idle, the car should have a steady pressure reading in the 3.3 +/- 0.2 bar, or 47.9 +/- 2.9 PSIG. You are nowhere near that pressure. A second critical fuel system test for these cars is delivery, or how much fuel volume is the pump putting out. In 30 seconds, your pump should deliver at least 850 cc of fuel. With the pressure you are describing, I’d be will to bet you are nowhere near that either. Something is obstructing the fuel flow. When was the last time the fuel filter was changed, and have you pulled it and at least checked it to see if it is blocked?

Good, you are back in business.

Check the crank position sensor, when they go bad the DME does not see the engine turning over and shuts off the fuel. When it does this, it won't throw a code but the car won't start.

If memory serves, there was an article in Excellence about the metal tube inserts that the hoses attach to coming loose on the Turbo and GT cars (they are apparently glued in and the glue sometimes fails). The “fix” is to get the inserts welded into place by a competent welding shop: You could be having similar issues.

I think he is refering to the OEM manual's recommendation that you should not remove the mount from the bracket as that could damage the mount: Some have commented that they have done what the manual recommends against, others remain more circumspect, or simply buy the OEM replacement with the bracket already attached.

Has the coolant level been dropping at all?

And who was it that said, "If you want to get into the real money, start a religion......" :eek:

Unbelievably, the Boxster service manual for the same year has a better image (the cars share many of the same parts), and it looks like the inside handle assembly has a couple of openings in it that the switch just snaps into, and then the cable plugs in. I’d also try to cross over the part number with a friendly VW or Audi dealer, they all share a lot of components. Sometimes these cars are just infuriating when it comes to small parts….

Shop around, I have found them online for $35-40 each. Have also made progress with some details, it is item #20:

I have not been able to find any diagrams or photos of how the inside handle switch mounts, but I did locate a part number: Inside handle microswitch: 996.613.123.00 (Same both sides). Perhaps if you can get a look at the switch, it may become more clear on how it mounts.

Scanning the DME is a normal part of any pre purchase inspection; any potential buyer sould be more than concerned if the current owner did not allow it. If you are planning to get another Porsche, the optimum scanning tool would be the Durametric Enthusiast software, which is Porsche specific and an excellent DIY tool. If you are not going to stay with Porsche, I would consider a more generic OBD II scanner like those from Actron, which will function on any brand vehicle but lacks some specific Porsche functionalities. The OBD port is located near the steering column, beneath the dash. And just for general reference purposes, when we do a PPI, all aftermarket HID installations are considered “deduct” items due to the inherent problems both with the kits and the problems they often cause.

The door lock micro switch in inside the door handle assembly; remove the door handle and lock cylinder, and simply unclip the switch (a small screw driver helps). This is covered in the new Bentley 996 manual (page 57-9) if you have access to one. If you do not have the Bentley manual, which is a great DIY tool, and would like to acquire one, there is a link on this site to the RennTech Amazon store where you can get a good deal on one, and the site benefits as well.

Have you checked the wiring harness for the sensors? It could be frayed wiring or a connector issue.

Mike, check the "News and Rumors" section, the photos of the new system are there.

While Techron never hurts, it will not clean out the intake runners, as the engine is a port injection type, so the fuel enters the intake system right at the intake port. It will however clean off the injector nozzles, so it is not a bad idea. P0420 and 0430 are three way cat codes for both banks and can be as the result of all the crud in your intake system. Once the AOS is fixed, and the intake systems cleaned out, clear the codes and take the car for a long, highway speeds drive so the cats get good and hot. That should clean them out . Sitting on jack stands, with the suspension hanging (not recommeded by Porsche), can cause issues with the suspension (corrosion on the exposed strut shafts), but will not do much else.

Be careful about doing a hack to run the fog/driving lights as DRL's, in many states in the US, the fog/driving lights must go out when the highbeams come on. If they do not, the car probably will not pass annual safety inspections.

Try 1432

Try 0698.

As you have to change the clutch fluid (which must use the PIWIS) twice for every time the gear oil is changed once, the dealer (or indy with a PIWIS) would be the safer bet.