997-crazy start problem....
Thread Starter
8th Gear
Joined: Jan 2014
Posts: 8
Likes: 0
997-crazy start problem....
O7-997-1, 39k mikes , started the car , drove two blocks parked for about 3mins, went to leave and it wouldn't start.... Sound like it was flooded, wanted to catch but wouldn't ...waited another five minutes and it started fine???? . It has been awhile since I have really excerised the car,, mostly just short trips . I did think I smelled that lovely sulphur smell after it finally started .... Any clues ? Is this a precursor to a fault
Any thoughts are appreciated ... This
Any thoughts are appreciated ... This
Cruisin'
Joined: Nov 2015
Posts: 9
Likes: 0
From: Illinois
Not knowing the service records my first guess at 39k is= time for a new set of plugs.. I wouldn't go off the deep end thinking computer problems just yet.
Sounds like you have perfect storm
1. Old plugs covered with carbon
2. Old plugs excessive plug gap
3. Shutting off car before it was to operating temp= closed loop. Computer term
4. Wet plugs spark wouldn't ignite the fuel.
5. Left car set 5min fuel evaporated enough for spark to occur.
Almost forgot to tell you to check air filter,, clogged filter can cause an over rich condition in open loop (cold start up till operating temp)
To go further would need to know service records, how old fuel in car ,maybe need a bottle of heet in tank.
SammyD
Sounds like you have perfect storm
1. Old plugs covered with carbon
2. Old plugs excessive plug gap
3. Shutting off car before it was to operating temp= closed loop. Computer term
4. Wet plugs spark wouldn't ignite the fuel.
5. Left car set 5min fuel evaporated enough for spark to occur.
Almost forgot to tell you to check air filter,, clogged filter can cause an over rich condition in open loop (cold start up till operating temp)
To go further would need to know service records, how old fuel in car ,maybe need a bottle of heet in tank.
SammyD
Last edited by SammyD; Dec 17, 2015 at 02:38 AM. Reason: Add to it
Racer
Joined: Jul 2013
Posts: 361
Likes: 6
Search for "slow crank / start when warm".
A common problem reported by quite a few 997.1 owners, including myself. Cause of the problem is either a bad electrical cable between alternator & battery, and/or a bad starter.
For my case, the problem went away after replacing the starter.
A common problem reported by quite a few 997.1 owners, including myself. Cause of the problem is either a bad electrical cable between alternator & battery, and/or a bad starter.
For my case, the problem went away after replacing the starter.
Last edited by Psymon; Dec 17, 2015 at 03:07 AM.
Cruisin'
Joined: Nov 2015
Posts: 9
Likes: 0
From: Illinois
Psymon brings up another good point, slow cranking. I assumed he knew the difference between "flooded" and slow cranking but he might not. So a proper charging system diagnosis should be in order.
Car sitting for long periods of time without trickle charging (battery maintainer) allows battery to lose precious voltage that's needed to operate starter. Back in the day you didn't have digital radios remembering your preset stations, clock time or security systems on cars. Now 95% of all vehicles have this which soon as you turn the key off starts the parasitic drain on battery. Number one cause of starter failures is starting vehicle with an undercharged battery =repeatedly. Doing it one time not a big deal doing it every week big deal.
Using a battery tender for a car that's not a daily driver makes good sense. By keeping your battery fully charged it prolongs battery life and ease of starter operation. I've seen this time again observing an increase of 2years in overall service life of battery. Ymmv
Seeing your car is rolling on the 40k service I'd do all the above so you can get to enjoying it and not guessing if and when it's going to start.
Wishing you much success in your repairs/service
SammyD
Car sitting for long periods of time without trickle charging (battery maintainer) allows battery to lose precious voltage that's needed to operate starter. Back in the day you didn't have digital radios remembering your preset stations, clock time or security systems on cars. Now 95% of all vehicles have this which soon as you turn the key off starts the parasitic drain on battery. Number one cause of starter failures is starting vehicle with an undercharged battery =repeatedly. Doing it one time not a big deal doing it every week big deal.
Using a battery tender for a car that's not a daily driver makes good sense. By keeping your battery fully charged it prolongs battery life and ease of starter operation. I've seen this time again observing an increase of 2years in overall service life of battery. Ymmv
Seeing your car is rolling on the 40k service I'd do all the above so you can get to enjoying it and not guessing if and when it's going to start.
Wishing you much success in your repairs/service
SammyD
Intermediate
Joined: Mar 2013
Posts: 46
Likes: 1
From: Mt. Lebanon, PA
I had the starter cable replaced on my 2007. I was always able to start it but it would be sluggish when warmer. Inspecting the cable before it was removed, you could see part of the plastic jacket melting. After it was removed, there were scorch marks on the connector and part of the braided copper was broken.
Burning Brakes
Joined: Nov 2006
Posts: 915
Likes: 18
From: Northern Nevada
Cam position sensor is a good possibility if it's cranking strong as mentioned. Another possibility is coolant temp sensor. Sounds weird but the computer needs to know the engine temp to get the mixture correct on a warm restart.
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Instructor
Joined: Aug 2013
Posts: 242
Likes: 102
From: Southeast Florida
When I first got my 997.1S I had the hard start when hot due to the battery cable. Initially I replaced the battery and starter. Eventually I learned about the cable issue and replaced the cable and alternator.
A few years later, I again had a hard start when hot. This time it was clear that the cable was not the culprit because it wasn't a slow start like before. It just seemed to need to crank over a bit longer before it would fire up. It was also very intermittent. I checked everything out and wasn't able to find anything wrong with the battery, charging or starting system so I lived with it.
Over time the car started having a rough idle when hot from a full day of driving and stalled on me a few times if the idle got too low during the rough idle. It would always start back up immediately, although a hard start with a long crank, and didn't sound like anything mechanical was wrong. Looked on the forums and did some homework and ended up checking the crank sensor. The sensor itself had some metal filings on the tip of the sensor and looked like it as seen better days. I didn't check it out thoroughly using an oscilloscope, but went ahead and replaced the sensor anyway and all has been well since.
Figured I'd share in case you can take a look at the crank sensor as well.
A few years later, I again had a hard start when hot. This time it was clear that the cable was not the culprit because it wasn't a slow start like before. It just seemed to need to crank over a bit longer before it would fire up. It was also very intermittent. I checked everything out and wasn't able to find anything wrong with the battery, charging or starting system so I lived with it.
Over time the car started having a rough idle when hot from a full day of driving and stalled on me a few times if the idle got too low during the rough idle. It would always start back up immediately, although a hard start with a long crank, and didn't sound like anything mechanical was wrong. Looked on the forums and did some homework and ended up checking the crank sensor. The sensor itself had some metal filings on the tip of the sensor and looked like it as seen better days. I didn't check it out thoroughly using an oscilloscope, but went ahead and replaced the sensor anyway and all has been well since.
Figured I'd share in case you can take a look at the crank sensor as well.
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Joe Kucinski
Instructor
Joined: Oct 2014
Posts: 144
Likes: 16
From: Vancouver, BC, Canada
Had the car for a little over a year and it has always cranked over slow, then started to get REALLY slow when re-starting after a drive--to the point where I would wonder if it was going to start at all. I just had the starter and cable replaced (cable looked fine but figured I may as well do it while the car was apart). What a difference! Cranks hard and fast now.
Three Wheelin'
Joined: Feb 2017
Posts: 1,965
Likes: 689
From: San Francisco
Like the other guys mentioned, those are classic symptoms of a bad starter/alternator cable. I have a writeup on it here: https://rennlist.com/forums/997-foru...e-997-1-a.html.
Your local Porsche dealer will likely quote you $3k to replace but a friendly indy will probably quote $1k or less (I think mine quoted like $650). The cable itself is only ~$150 so if you have access to a lift its not that bad of a DIY.
Your local Porsche dealer will likely quote you $3k to replace but a friendly indy will probably quote $1k or less (I think mine quoted like $650). The cable itself is only ~$150 so if you have access to a lift its not that bad of a DIY.
1st Gear
Joined: Dec 2021
Posts: 1
Likes: 0
Sorry for replying to an old post. I have a 2005 997 Carrera that had the slow start sometimes no start when trying to start when the engine was warmed up. I also more recently got the stalling and the subsequent rough running engine mentioned above. I did replace the starter cable, but what fixed it was the crank position sensor (maybe previous owner replaced because starter cable looked good).When it was just a hot start issue I thought it was the wire so was set on fixing that. Have had zero start or stalling issues since the crank position sensor was replaced.
Last edited by riot8088; Dec 8, 2021 at 03:38 PM.
Poseur
Rennlist Member
Rennlist Member
Joined: Nov 2005
Posts: 17,740
Likes: 291
From: Santa Barbara, CA
There are many parts that can result in that symptom. Many of us had issues with our early 997 cars and supposedly the solution was to replace the electrical line between the alternator and the starter. It could also be the starter, but proceed there with great caution, I got an estimate from my local ‘stealer’ for an unbelievable $2350 just to replace the starter. (My brother in law, who’s in the business said with a new Bosch Porsche part could be done for between $500 and $600.)