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tradergarry

Starting issue, cranks won't start

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Hi

Hi, I could use some help. My Boxster left me stranded at a light. Would crank but not start. After checking fuel pump fuse was ok I had it towed home. I jumpered pins 30 and 87 on fuel pump relay and it started. Ordered relay from Pelican. Installed, it started, drove 5 miles to an appointment, then would not restart. Towed home. Before I hooked up Durametric I tried ignition and it started. Durametric revealed 6 codes. The first one has been ongoing. The last 5 are new.

P0455:Porsche fault code 94 - Tank vent system (major leak) P1130:Porsche fault code 361 - Oxygen sensing adaptation idle range bank 2 P1341:Porsche fault code 174 - Camshaft adjustment bank 1 below limit value P1579:Porsche fault code 111 - Crankshaft sensor P0336:Porsche fault code 110 - Engine speed sensor Open circuit P1124:Porsche fault code 167 - Fuel pump relay below limit value

Regarding the first ongoing code, I've replaced the gas cap, carbon canister, vacuum canister, secondary air vac valve, 2 check valves. Still got that code but was running fine so I ignored it awaiting more insight. Also I've replaced the fuel filter less than 10,000 miles ago.

I did not think to unhook maf during start failure. I did replace it within 10,000 miles though. It was running normal prior to problem. I did detect a very slight miss at idle similar to when I had a hairline crack in a coil pack.

Any help would be greatly appreciated.

Thanks, Garry

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The MAF has nothing to do with starting and little effect at idle. It does 95% of it's work above 4000 RPM.

You have both a fuel pump relay issue and a tank vent leak issue - I think you start by solving those.

Measure the fuel pump output. If you do not have the tools to do that have a shop do it for you.

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I think you should also check the crankshaft position sensor. If it can't pick up a reference point when cranking it won't fire the coils.

Edited by Richard Hamilton

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Thanks guys, Yes I have a flow meter, and I'll do a test. The tank vent issue is ongoing and I've thrown hundreds in parts at it but it reoccurs. I can drive several hundred miles on the interstate and the cel will not come on. 50 miles around town and it's on. I've noticed it will cold start but not hot start. Does cold starting eliminate crank sensor? Does it imply something else? I also checked the grounds on each side of the computer in rear trunk and they are ok.

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Last night I started it, erased codes, and let it idle until it died about 15min. Warmed up to 180 degrees. Code popped up immobilizer failure. Should my next action be to remove the drivers seat and check the immobilizer fuse? Or will it start at all if that's blown?

Thanks

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In a Boxster, you can remove the driver's seat without having to disconnect the electrical connector under the seat, thereby avoiding setting off the airbag light, which can then only be reset with a PST2, PIWIS or Durametric. The wire under the seat is long enough to allow you to unbolt the four bolts that hold the seat rails in place, pull it out and set it on a platform that you can set up next to the door sill.

You could also just unbolt the four bolts that hold the seat rails in place, operate the seat back so that it's leaning as far forward as possible and then tilt the whole seat backwards. Then you just put a wood block under the inboard (now unbolted) seat rail and you can have pretty good access to the immobilizer. Aside from inspecting the fuse, which is at the rear of the unit installed on the short vertical face, you should check for moisture or corrosion on the circuit board inside.

Since your car is operating sort of intermittently, it's not likely the fuse that would be the source of the trouble in the immobilizer. If you find corrosion on the circuit board and it hasn't been a long standing problem, you may be able to clean it with isopropyl alcohol and get it back to operating condition.

Regards, Maurice.

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Thanks Maurice.

I pulled the immobilizer today, cleaned it well, checked solder joints under magnification. Replaced and same old thing. An engine speed sensor code appeared on durametric. Also while it was still running, I revved the engine, and observed if I stomp the gas quickly, there's a hiss, slight hesitation, then revs ok. I liken it to a loose or missing vacuum hose symptoms on other cars I've had. Is there a way to narrow down a vacuum problem with the durametric? I checked the small lines on the large hose by the throttle body. I assume speed sensor is crank sensor. Can the crank sensor be cleaned or adjusted, or just replaced? I do hear a click on the carbon canister valve. I know I can do tons more with the durametric than I'm doing. Not sure what all the values imply.

Any feed back appreciated.

Garry

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Which of the purge valves are you referring to: the one by the EVAP cannister under the right front fender, the one at the end of the line there, or the one under the intake runner in the engine compartment?

Regards, Maurice.

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Hmm. I didn't realize there was more than one. I just remember reading a post that they could be problematic in relation to similar problems as mine. Can they be tested with the Durametric? I think was going to replace the one by the carbon canister at one time but I kept getting the wrong one shipped to me. My canister has three fittings on top and none on the bottom. The piece I got was for the canisters with a fitting on the bottom. Is there a way to trouble shoot them by being able to blow, or not blow through the hoses?

Thanks,

Garry

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When ever you get a crank with no start condition, please remember there are a couple somewhat unique design features to these cars. First, the Bosch ECU does not turn on the fuel pump relay (never) unless it is getting pulses from the crank position sensor. This means, if the engine is not turning under crank or run conditions, there is no fuel pressure. This is intended to help prevent engine fires. So, if the engine will not start, you have to do the old fashioned check for fuel and ignition. Since these cars do not have fuel pressure sensors, the OBD will not be any help here. Pull the FP relay and jumper the pins with the ignition off.

Remove the fuel cap and have someone turn the ignition on (not crank) while you listen at the filler neck, If you hear the pump run continuously , the pump is probably fine, but you still have to do a pressure check at the engine fuel rail to verify actual pressure meets spec. for a complete check of the fuel delivery.

If the pump does not run, leave the relay jumper in place and check for 12v at the pump elec connector under the battery.

No voltage there means a wiring problem. These pumps often fail to spin intermittently on a start-up before they quit completely. So if you get it restarted , don't shut it down until you are home.

If the pump checks out, pull a spark plug connector and check for spark with a clean plug and everything properly grounded. If there is no spark, the problem is likely the crank or a cam sensor. You will have to go the manuals for this procedure.

While on the subject of fuel pumps, it is interesting to note the early 986/996 use the same pump as millions of VW's and Audis going back to 1993. While the pn's may vary (often because they are sold with the sender) the pump is the same unit.

Examination of the performance specs is so close, it makes no difference to the engine. Phycical examination with a vernier down to the detail part level cannot find any difference at all . The pump you want is the Airtex equivalent of their pn E8366. These can be shopped for as little as $50 (as opposed to $300 for a VDO), or a salvage yard find if your budget is challenged. When you pull the top off the old pump assembly, you will find the classic alum can turbine fuel pump inside. About the size of a roll of 50 cent pieces. Nothing special.

Pelican parts has a good article on FP replacement (with the exception of chiseling off the retaining ring). Get or make a tool for this, it will save a lot damaged hardware, cost, delay, and a possibly dangerous hazzard. .

Bill Ryan

Casper Labs

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Thanks,

The crank position sensor did the trick.

The latest venture is to replace the cam position sensors. But I'm having a hard time finding them. 2000 2.7.

Anyone replaced these? Bentley says left front and right rear, but I'm not finding them.

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Posted (edited)
On 2/21/2014 at 1:04 PM, casperlabs said:

When ever you get a crank with no start condition, please remember there are a couple somewhat unique design features to these cars. First, the Bosch ECU does not turn on the fuel pump relay (never) unless it is getting pulses from the crank position sensor. This means, if the engine is not turning under crank or run conditions, there is no fuel pressure. This is intended to help prevent engine fires. So, if the engine will not start, you have to do the old fashioned check for fuel and ignition. Since these cars do not have fuel pressure sensors, the OBD will not be any help here. Pull the FP relay and jumper the pins with the ignition off.

Remove the fuel cap and have someone turn the ignition on (not crank) while you listen at the filler neck, If you hear the pump run continuously , the pump is probably fine, but you still have to do a pressure check at the engine fuel rail to verify actual pressure meets spec. for a complete check of the fuel delivery.

If the pump does not run, leave the relay jumper in place and check for 12v at the pump elec connector under the battery.

No voltage there means a wiring problem. These pumps often fail to spin intermittently on a start-up before they quit completely. So if you get it restarted , don't shut it down until you are home.

If the pump checks out, pull a spark plug connector and check for spark with a clean plug and everything properly grounded. If there is no spark, the problem is likely the crank or a cam sensor. You will have to go the manuals for this procedure.

While on the subject of fuel pumps, it is interesting to note the early 986/996 use the same pump as millions of VW's and Audis going back to 1993. While the pn's may vary (often because they are sold with the sender) the pump is the same unit.

Examination of the performance specs is so close, it makes no difference to the engine. Phycical examination with a vernier down to the detail part level cannot find any difference at all . The pump you want is the Airtex equivalent of their pn E8366. These can be shopped for as little as $50 (as opposed to $300 for a VDO), or a salvage yard find if your budget is challenged. When you pull the top off the old pump assembly, you will find the classic alum can turbine fuel pump inside. About the size of a roll of 50 cent pieces. Nothing special.

Pelican parts has a good article on FP replacement (with the exception of chiseling off the retaining ring). Get or make a tool for this, it will save a lot damaged hardware, cost, delay, and a possibly dangerous hazzard. .

Bill Ryan

Casper Labs

 

Thanks Bill, your post helps a lot.  Old thread, but still valid.  BTW, Volkswagen alternators also fit into the 996 at a fraction of the cost of OEM.  It's been a long time since I've posted since I've basically had my MY 2000 996 cab-4 garaged for the past several years.  I would crank it occasionally but haven't driven it much at all.  Now I have a "crank no start" situation.  There is no CEL and no fault codes.  The battery is good.  I have a 1/2 tank of old gas in it and my first thought is that it's bad gas.  I put a whole can of seafoam in it and it still wont start.  I intend to fill it the rest of the way up with fresh hi-octane fuel and try again.  Meanwhile I am researching what my troubleshooting path should be.  If the new gas doesn't work, I'll jumper the fuel pump to make sure it's working.  I sure hope I do not have to pull a spark plug to check for spark though, because it sounds like I would have to jack the car up and drop a muffler to get to a spark plug (or maybe there is at least one easily accessible plug on the 996... I'll have to check).

Edited by vette67
improved

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Is the tach needle “bouncing” when you spin the engine over?  If it isn’t, your CPS is out and the DME is not allowing the fuel pump to turn on.

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Well, the new gas didn't help and I've been travelling, so she has been sitting dead in the garage for another several months but I did get a new crank sensor, fuel pump relay to install if necessary.  I'll be home this weekend and need to put in a new battery and check again to see if the tach needle moves at all when I'm cranking.  If it does, then I'm going to listen very carefully for the fuel pump.  If no sound then I'll jumper the relay and try again.  If none of that works I'll check for 12 volts at the pump and get a new one if necessary.  Found a great youtube video on how to DIY replace it... doesn't look too hard. 

 

I'll let you guys know how this is going.  Thanks again for your help.

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What signals at the DME are required for the dme to engage the fuel pump?

 

pin 66 on my spec boxster is not pulling to gnd.

 

My dme/immob/key have been tested and are good.

 

mike

 

 

 

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