996 Starting Issue

[husker boxster]

Had someone come to look at the 01 911 this morning, so I pulled it out of the garage and into the driveway. He took it for a drive and she ran like a well oiled machine. Get done with the drive and he parks her in the driveway. They leave and I'm going to put her back in the garage. Starter / engine spins and spins, no ignition.

I check for codes, but none on my Bosch reader. I pull the crankshaft position sensor & find some ohm reading specs on the net. Go to OReillys and it appears to be w/in specs.

Any ideas? Not sure why it would be working one min and not the next. I'll put the CPS back on and recheck for codes.

[dghii]

Fuel pump relay? Usually will fail warm and them work when cooled back off.

[husker boxster]

I let it sit for multiple hrs and it still wouldn't start.

Should add the tach needle moved slightly when bumping the starter.

Will have someone hit the starter tom to hear if fuel pump activates.

[Gelbster]

The tach should bounce just a little when you crank.
There is a convenient fitting to check fuel pressure with a Schrader valve+cap.
The fuel pump relay is an oddball with the tiny 5th pin. Should proly carry one as a spare anyway. Alternatively just make a jumper to test it.
https://www.renntech.org/forums/topic/44462-no-startingpossible-fuel-pump-or-relay/?_fromLogin=1

[husker boxster]

Put the CPS back in, started right up. Took her for 10 mi drive this morning and parked in the garage. Waited 30 min and she started right up.

I hate intermittent problems. Still no codes on my reader.

[Gelbster]

Sometimes I suspect such issues are just bad connections.Time will tell.

[Nine8Six]

Originally Posted by husker boxster

Put the CPS back in, started right up. Took her for 10 mi drive this morning and parked in the garage. Waited 30 min and she started right up.

I hate intermittent problems. Still no codes on my reader.

Refill a full one with fresh gasoline? Season/temp change = condensation. High risk for a garaged car that occasionally goes in/out and is not driven often. Although I do not recommend you to run the car if indeed you do have water contamination, could be different for a Honda mind you.

If the case, water needs to be taken out. Bet there are tons of comm products available to deal with this problem.

Wild guess there, g-luck

[Giller]

Originally Posted by Gelbster

The tach should bounce just a little when you crank.
There is a convenient fitting to check fuel pressure with a Schrader valve+cap.
The fuel pump relay is an oddball with the tiny 5th pin. Should proly carry one as a spare anyway. Alternatively just make a jumper to test it.
https://www.renntech.org/forums/topic/44462-no-startingpossible-fuel-pump-or-relay/?_fromLogin=1

Funny how when someone asks for advice about a 987 you give them grief and tell them to look in the 987 section.....

How come no comment about looking in the 996 section??

[Boxtaboy]

Maybe they took it for a drive and swapped out some parts before returning it!

[Gelbster]

Originally Posted by Giller

Funny how when someone asks for advice about a 987 you give them grief and tell them to look in the 987 section.....

How come no comment about looking in the 996 section??

I gave no grief.You did.I said "ask in 987 section " and went on to offer a complete answer to the OP's question. You offered no such help.


Why did I help Husker ? Because I was able to. Simple. It is an M96. The 987 is very different as I explained by citing Porsche literature at the time.

Seems your Trolling me. That tells us all about you right there. Happy Trolling

[husker boxster]

Originally Posted by Gelbster

Why did I help Husker ? Because I was able to.

I appreciate everyone's input.

I apologize for asking a 911 question on a 986 forum. I didn't mean to reopen any healing wounds. Yes, there are other 911 specific forums and I had done a lot of reading of threads on them before asking my question here. But I'm not a member on any of those forums and this is my 1st 911. I split time between here and P-9 and a small bit of time on Quattroworld, so I didn't want to join another forum. I recall several recent "my Boxster won't start" threads here and most pointed to the CPS. I don't recall if any responded back that that fixed the issue. Since my issue didn't seem to point to the CPS, I was hoping someone would have other suggestions. Short story long, my question may not have been appropriate here but I trust the brain trust of this forum.

Originally Posted by Boxtaboy

Maybe they took it for a drive and swapped out some parts before returning it!

I rode with the guy for the long test drive but he wanted to take wifey on a short drive in the neighborhood to see if she liked the car. I forgot it has a 'back seat' and let them go by themselves. So they had opportunity. When they got back, we went thru all the buttons and the one that stumped me (it's been 9 yrs since I had my 01S) was the button with the key on the upper right horseshoe. We pushed it back and forth and I wondered later if it immobilized the engine. Have since found out it's the central locking button.

[Gelbster]

"I appreciate everyone's input."
You are welcome.It is an M96 with a potential CPS problem. So all that is suggested is 100% relevant to the 986 Boxster also.
Back to the CPS. The heat related failure mode can be simulated. The procedure requires you remove the CPS , connect a DMM and watch the Ohms change when you heat it with a powerful hairdryer.
JFP an expert(unlike me!) suggests specifically( and I know you may have done this part of the diagnostics already):
"Remove the CPS sensor connector, connect your Multimeter to pin #1 and pin#2, at 68F it should read 0.8-1.0K ohms; then connect the multimeter to pin #1 and pin #3 and it should read infinite ohms; if it does not read correctly in either range, can the sensor and replace it. "
https://www.renntech.org/forums/topic/50726-cps-readings/?_fromLogin=1
At least it is a simple job with a reasonably priced part :-). Good Luck and let us know what the fix was.It may be an omen - keep the car !

[husker boxster]

Thanks Gelbster.

I did the ohm test with a room temp CPS and got those figures. Didn't try the test with a hot CPS. My brother spoke to noted Porsche mechanic Karl in KC and Karl's suggestion was to replace the CPS. Just did some Internet searching and found one for $112 + $10 shipping, so a new one is on its way.

[Giller]

Originally Posted by Gelbster

I gave no grief.You did.I said "ask in 987 section " and went on to offer a complete answer to the OP's question. You offered no such help.


Why did I help Husker ? Because I was able to. Simple. It is an M96. The 987 is very different as I explained by citing Porsche literature at the time.

Seems your Trolling me. That tells us all about you right there. Happy Trolling

Wow dude, totally false. You were the first to post in the thread and said simply 'look in the 987 section'. Yeah, that's a lot of help. You only offered your advice after I called you on this (you even quoted me). And I was the first in the thread to offer any advice to the guy.
Nice work Sean Spicer!

[Gelbster]

I am confused about the standard test we are discussing. It is unclear to me if the 68F ,0.8k to 1k Ohm test predicts a hot failure or just at 68F.
Obviously if you get zero or infinite ohms it is clear. But what is a typical reading for a CPS like yours which works fine when cold yet fails at some point with heat/heat soak?
That is why I mentioned the hairdryer .No idea if it is necessary. When you receive your replacement, you will have an excellent opportunity for a comparison test.
I did find n unverified suggestion that a sign of failure is a reading close to the lowest end of the range .Maybe if you get less than 850 Ohms, replace anyway ?

[911monty]

Originally Posted by Gelbster

I am confused about the standard test we are discussing. It is unclear to me if the 68F ,0.8 to 1 Ohm test predicts a hot failure or just at 68F.
Obviously if you get zero or infinite ohms it is clear. But what is a typical reading for a CPS like yours which works fine when cold yet fails at some point with heat/heat soak?
That is why I mentioned the hairdryer .No idea if it is necessary. When you receive your replacement, you will have an excellent opportunity for a comparison test.

Since resistance changes with temperature ie resistance increases as temperature increases, then the standard test simply defines expected resistance values (0.8-1.0 OHM) at a specific temperature (68F) for a functional CPS. This prevents having to define resistance values at different temps.
The heat test simply tests for gross failure when hot such as a break in continuity due to expansion. At least this is my take.

Is this what is confusing?

[Gelbster]

No. A degree in Physics helps but not enough !
A CPS with an intermittent heat related failure mode - What ohms does it show at 68F ?
Answer : around 0.9k ohms. ??? More, less?
Question - How do I test it without heating it, to produce either infinite or zero Ohms to confirm the defect?
Maybe the heat related failure also produces a higher/lower Ohms reading at 68F ?That would be a convenient clue. No Hairdryer required.
For example - maybe the CPS components are being gradually degraded by heat cycling and a CPS with heat related intermittent failure reads lower than 850 ohms at 68F ??
I am trying to find a definitive value that correlates to heat related failure. Maybe trying too hard.

[Gelbster]

Originally Posted by Giller

Wow dude, totally false. You were the first to post in the thread and said simply 'look in the 987 section'. Yeah, that's a lot of help. You only offered your advice after I called you on this (you even quoted me). And I was the first in the thread to offer any advice to the guy.
!

You gave generic, misleading advice that had little to do with the big 987 issues - just check the links I gave .Those links gave advice from experts(not me and obviously not you !).
http://986forum.com/forums/general-discussions/66123-looking-buy-2010-12-boxster-post533583.html#poststop
First , do no harm. You mislead the poor guy! I helped him in just a few words.
Keep on Trolling me -it is an effective warning to other Forum members to be wary of Giller and Giller's misleading advice.