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J_STATUS

When used in short errands trip, car won't turn sometimes it takes

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I had the same problem. The cause was the neg batter terminal was not fully tight. After tightening it up, she cranks like a champ! Hope this helps someone with the same intermittent starting issue!

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Hi J_Status,

Have you looked further into your problem?

Mine would do the exact same thing, whereby the first attempt would be a small crank, the second seemed to stop at the compression stroke and the third would do the trick. Sometimes I would need to open the spoiler to cool the engine and go for a walk to cool myself off!!

After the car left me stranded, I phoned roadside assistance and they checked the battery and it was fine, although they had to use their heavier duty jumper machine. This had convinced me it was either the +ve cable from the jump point/alternator/starter or in fact the starter motor. Considering you need to remove the throttle body and intake distributor to access either of these items, I was not going to do it twice, therefore I changed both.

WOW!

What a difference, no more lazy starting, the thing turns over like a jet engine (hot or cold) and the battery gauge on the dash has never shown such a high reading. I can only imagine the cable was on it's way, however, I am extremely glad I did both!

It is so good to have confidence back in the car, especially when it is a daily driver.

Peter.

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I have this exact problem, I was wondering if yours as well once you do get it to start it has a very inconsistant idle dropping as low as 600 RPM and jumping up to about 1200, where as it usually just sits at 800. once I set off the car will idle properly at stop signs/stop lights, but at first it has this problem.

also I found that if I pump the gas a little it will start up a little easier when having this problem. It could just be mental, or it could actually be helping. would this help diagnose my problem or is this consistant for all the possible issues discussed above?

Thank you,

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I would definitely check the battery connections. If they work lose when the engine is running there is no resistance in circuit to quell voltage highs from the alternator. The result can be a fried ECU.

I have had a similar problem to the one you mention with the car not starting, but in my case it would not crank when very hot. It was not a Porsche, but a different make. I traced the problem to a female spade connector on the starter motor. When it was hot it had insufficient clench to deliver a signal to the starter solenoid. I know your problem is not cranking, but not starting. In order to start there must be a spark and the delivery of a spark depends on the supplied voltage. Now if the battery terminal is slack when it's hot there will be a high resistance which in turn decreases voltage.

First check the battery terminals are tight. Next check the voltage at the terminals by touching the lead posts with a voltmeter. Next check the voltage on the outside of the terminal clamps. Next check the voltage at the jump start point in the engine compartment. All three of these should have almost the same reading, although the one at the jump start will be slightly less.

These three would be good starting points.

Next check the voltage when the engine is being cranked. If it's below 9v I would say it's unlikely to start and you have a bad connection somewhere.

H

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I haven't has any time today to do anything to the car, but I did pay attention to the volt meter in the gauge cluster and I noticed that when the engine was cold t would over around 14 volts, once the engine started to heat up it dropped and stuck around 13 volts.

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I've been having this issue - when car is hot. Sometimes starter won't crank first time, but always starts second time. I've read starter solenoid, ^ CPS, etc. anybody nailed it down further?

I will check battery, connections, but I don't think that's the issue.

Edited by JG 996T

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This is a well documented problem on the 996 and some early 997's as well -- do a search and there's a lot of good information.  The bottom line is you will need to do some troubleshooting.  It could be your CPS but is more likely a wiring harness that is the well-known culprit.  Pretty common that the issue is exacerbated when the engine is hot as resistance increases as heat increases.  Best to do some troubleshooting before throwing parts at it.  Ahsai had a nice write-up in the past with diagrams if you DIY.  It's pretty simple in theory -- however practically speaking I personally found the wiring harness a bit difficult to get at in the M96.  Never had to do it in my 996TT but I'm pretty sure it's not any easier.

Edited by Silver_TT

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Where is the CPS located? Edit: Found picture on 6speed. Issue did not present this weekend, hot or cold. I'm going to charge battery tonight. Battery is from 11/12. Car is not driven daily.

Edited by JG 996T

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On the driver side of the bell housing, pointing at the flywheel timing teeth.

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I agree with Silver though your problem sounds more like a wire harness issue because the starter doesn't even engage sometimes, which has nothing to do with the CPS. To diagnose it further, you need to check why the starter is not spinning by checking the starter relay, clutch switch, and ignition switch if you can reproduce it with confidence.

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The starter always engages, it just stops mid-crank (like the last crank before battery is dead). And then car starts on second - full crank.

Edited by JG 996T

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The starter always engages, it just stops mid-crank (like the last crank before battery is dead). And then car starts on second - full crank.

Um, that can't be the CPS, which will not stop the starter. A bad CPS will just let the engine crank but never fires up.

One case I know was the engine is so hot that makes the starter seize due to the close tolerance of the starter. The coolant fan on that car were not working. How hot was the coolant when this happened and are your coolant fans working at both low and high speeds?

Edited by Ahsai

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Where is the CPS located? Edit: Found picture on 6speed. Issue did not present this weekend, hot or cold. I'm going to charge battery tonight. Battery is from 11/12. Car is not driven daily.

Definitely load test the battery.

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Charged battery. Took a long ride. Stopped and started hot 3-4 times. No problems - full crank start each time. Will get battery tested when I have a chance.

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Definitely good to get the battery tested -- it's easy, free, and a battery that's not at 100% can cause all sorts of headaches.

 

Electrical problems in these cars are, in general, very annoying.  They can manifest themselves with all sorts of strange behaviors and often aren't reproducible, making them difficult to track down.  If the problem persists, it could be a number of things, but the harness would be the first place I would start. . .especially if this has never been replaced in your vehicle.  Much more likely than a CPS, and it doesn't sound like it's the CPS anyway.

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