930 non start issue- continued
 

My '87 930 was intermittantly not turning over when ignition key turned.

Replaced starter motor, battery, new permatune CD and coil, new OEM spark plug wires and plugs. Cleaned earth strap connection to bodywork.
original symptoms: car would not turn over when warm, could be 'bump started' or paralleled with spare battery and start, even though original battery good.

(Car was recently picked up from the UK in VERY cold weather with heater on most of the time- but booster footwell fans were inoperative as heater was jury rigged with heat exchanger valves manually forced open)

More recently it did not start/turn over, one morning when cold.
I also fixed the heater system to work thermostatically as designed, with footwell booster fans working.
After cleaning the tranny earth strap, car ran GREAT no non start issues for about 1 month (weather was very mild and heater was rarely used).
I was just about to remove the spare battery from the car when....
This morning (frosty weather) it stalled when I went over a speed bump at 5-10mph. Coasted to a stop and it restarted, then stalled again whilst driving along 10-15mph. Had non start a few times and finally was okay after I turned the heater off.
I had the heater on high and the window open - as I love the sound of my Fabspeed muffler!.

On the way home I had the heater off- no problems.

When I got home I tried to replicate the symptoms.

I let her idle with heater on high and windows open (heater works with a thermostat, so with windows open the heater remains on high booster fan speed)
After 5 minutes the car stalled, restarted and stalled again a few minutes later. A couple of times the car would not restart.
I had rigged up a voltmeter to the ignition yellow wire and got over 10v when turned and no start.
When testing this voltage, after a few seconds with the key turned and reading 10.3v the engine suddenly turned over and burst to life!
Ignition switch tumbler was very warm but not red hot

Heating seems to be an issue here- may not be the main problem but seems to agrivate the intermittent problem

- Any ideas what this points to?
Bad yellow wire or bad ignition switch?
I believe I can buy just the electrical section of the ignition switch?

Any other tests I can do?
Maybe sit with a hair dryer on the ignition switch and see if symptoms re occur?

Any ideas which route I might follow?
Thanks
Ben

The heater ventilator switch and relay connect to the yellow wire circuit at terminal 1 on the 14 pin connector.

I don't understand why the starter solenoid (yellow wire) circuit is required to be connected to the HV switch and relay. Maybe it's to kill the HV motor when you turn the car over?

I am not sure what fails on a relay or what it can impact if it does. Fuse 22 energizes the relay at terminal 86. Could voltage "cross over" to terminal 85 from 86 and cause some of the symptoms?

http://forums.pelicanparts.com/uploa...1299820550.jpg

Twin Plugged Targa - Not sure why you did not just bump the old thread back up instead of attaching your above note to the original

http://forums.pelicanparts.com/porsche-911-technical-forum/584273-stranded-assistance-please.html

There is a lot of good info in the original thread and I see where Joe Bob said to wire a volt meter to the circuit for testing - I think he was talking about the yellow wire circuit. Grady Clay provided some sound advice on the solenoid and battery.

The fact that it took two seconds to fire the car with the start circuit engaged (and having juice to the yellow circuit the full two seconds prior) gives you some good but weird data - another raised eyebrow towards the solenoid?

Given your car stalled when idling (and when going over a bump), don't you have a symptom now that is separate from the starter circuit?

I would pull the ventilator relay for fun to see if it isolates anything. I would take a look at terminal 1 on the 14 pin connector for corrosion, etc. Then I would replicate the failure and see if juice gets to the solenoid - or at least terminal 1 when present at the switch.

The fuel pump is fed through terminal 15 on the ignition switch (at least on the SC diagram) so if that connection fails the car dies - at least from what I can read from the diagram - I am no electrician - just trying to get you going.

Just to clarify, your no starts now are not a result of the motor not turning over?
In other words the motor turns over as normal but won't start?

Thanks for the input Bob
I did not revive the original thread, because last time i did, I had a sarcastic comment :
'Are u still stranded a month later ? Its tough to live in your car or on the roadside that long'

I guess I should have posted a link back to the original thread - thanks for that

These intermittent problems are the hardest to replicate, however I think I 'may' have found a link with heater usage and the non start/stalling.
Originally on the ride down from Uk to France when I nearly got stranded, the heater blowers were not in operation, only the flaps on the heat exchangers forced open.
I will try and make time tomorrow to use a hair dryer under the dash to warm the area and see if I can get similar results- stalling/non turn over.

To clarify it has always been a non start in terms of not turning over/ starter motor not operating.

But yesterday it did stall 3 times under normal gas, once on a speed bump and other times on the flat.

This was replicated at home that evening when I had the heater on full blast and the windows open

The heat may be aggrivating a problem, but if I can at least narrow down the effected area, this may help me pin point the problem.

This morning there was another symptom which may be totally unrelated:
The stereo and the speedometer were inoperative for the 1st 3-4 miles then came on by themselves? has never happened before.

I am not an electrical wizard but will hunt down the heater blower relay and remove (plus check/clean as many pins and electrical connections) and see what transpires.

Dont think it is fuel pump relay as there are 2 fuel pumps and relays, plus the car symptom is not turning over, not 'non firing'

Thanks for your patience
Ben

Radio and speedo both receive juice from the ignition switch. I think that switch is failing.

Edit - Also the fuel pump relays can be fine - but if terminal 15 on the ignition switch loses it's connection I think the fuel pump dies. If the radio terminal in the ignition switch loses it's connection the radio dies. if the speedo terminal in the switch loses it's connection the speedo dies (pretty sure but not absolutely sure). EDIT #2 - Looks like lots of other stuff should die if terminal 15 is disconnected in the ig switch so I am going to chill on throwing out my electrical guesses. But the radio is fed directly from the switch on a single wire that goes to nothing else.

I think the heat and/or bumps physically alter something in the "tired" switch and break connections. You are doing the right thing by thinking it through before throwing parts at the car.

Hi Bob
I managed to get the stereo to cut out intermittently with a hot hair dryer on the ignition switch so this may the next area to address.

the rear of the ignition switch is a plug and socket, I unplugged and plugged it but no change.
I guess I will need to replace the plug and socket section of the switch. The socket is held on with 2 awkward screws which will be a challenge , especially as I have a bad back at the moment :(

I could not find the 14 pin connecter in the luggage compartment. Can you give any more direction to it's location?
Is it near the fuse/relay holder? or nearer the dash end of the compartment?
Thanks
Ben

Nice idea on heating the switch. The switch is failing internally. Connections are not the issue - well the external ones are not the issue.

The 14 pin connector is in the drivers rear corner of the engine compartment. Back by the rear tail light. A big fat cluster of bound wires feed into it. I would not take it apart until you change the ignition switch. I would not touch another thing until it is replaced. I think it IS your only problem.

I would take the driver's seat out to get to it. Small nimble people really make me mad. Keep us posted.

PP has to ship overseas. $90 + shipping. I suppose there is duty as well.
.

14 pin connector is on the left side of the engine under the black plastic triangle cover. Remove the wing nut.

Intermittent electrical is a PITA. Starters have two typical issues, power from the key switch and balky solenoids which get low voltage. Di electric grease turns to tar like grease from the years of exhaust heat and no maintenance.

If it's the switch....replace it. There are a few threads on saving the tumblers so you don't have to re-key the car.....if it's the starter. You can band aid it with hot start relay, bang it with a BFH and/or pull the starter and replace/lube the solenoid.

BTW, there are no NEW Bosch SR68X starters. They are all re-manufactured units. They only fix what they have to and typically it's not the solenoid.

Sarcasm is a necessary evil on the board. Learn to live with it....nothing personal. %^B

When I recommended adding a meter...it was to track down where your voltage is dropping. You stall out check the meter, if you 12v+ at the key switch....it's not the problem....

You can also looks for serious voltage drops on starting. The poorman's load test....meter on the battery, watch the voltage drop with the LIGHTS on and starter engaged. If it drops under 10 volts. You have a suspect battery even if it's showing 12.5 at rest.....

If it's above that....good battery. Now test the drop on the starter circuit. Watch for drops. BIG drops will indicate a suspect electrical unit. Solenoid, battery cable, bent starter shaft, or any of a number of issues a 25+ year old starter circuit can have problems with.

you have mentioned several things that hvae caught my attention.
10v at the yellow wire.(to the starter). voltage is a tad low, but, what a voltage test does not tell you is if there is enough current available to pull in the solenoid.
one way to tell if you have good current is with a test light. connect the TL to a good battery and note the intensity. then connect it the yellow wire, while still connected to the starter, and try to start the car. if the light is noticeably dimmer, you have resistance in the start circuit.

another was the hot ignition swtich.
that can be caused by a lot of current, or resistance in the switch. that could also make the car cut off.

next was the car alarm.
after market car alrams are crap! they cause more problems than you can imagine. depending on how it was wired in, it can cause both problems.
what is so bad about the car alrams is that they are wired into the exsisting circuit, which leaves room for problems. either due to piss poor work or just the fact that the start ciruit needs lot of current, so 2 more splices and usually another relay, can reduce the power to the solenoid.

there are lots of things that can make the car shut off, but with it firing right back up, if it turns over, makes me think electrical connection.
clean all the fuses and fuse holder. wiggle wires around while it is running. check connectors

dont worry about the comments.
personally i would have just ignored it, but what surprises me is how hard some guys will be on new people.

Thanks guys
Have got a new ignition switch (electric section) and will try and fit this week.
Kinda busy trying to sell the 911T (have a possible buyer) and with work.
- The voltage tested at the yellow wire from igniton switch was measured over a split second as it fires immediately - I mean really fast!
It turns over fast and fires almost on the 1st cycle - I have never had a car starter turn so fast or start as quick on ANY car.
I will install the starter and run with that for a while and see if the problem raises its ugly head - with the heater on etc!
Thanks for all of the added info/suggestions
Ben

the time to check is when it will not start. you know the old saying, cant fix it if it aint broke.

Update-
purchased ignition switch (electric section) - from my local tech guy which fell apart in my hands (badly crimped) 'ditched' it
Purchased another ignition switch driedct from Porsche main dealer - installed and started fine 'yahoo!'
Battery was low (around 10.5v) and would not start car so jumped the car and ran it for a bit.
Charge on battery terminals was showing 13.4v so figure a good run would sort out (this was a new battery)
Stopped and started the car after 5 mins at idle and no problem on restart.
Took my keen 4yrs old daughter for a test run (she was as keen as punch wanting dada to 'go faster!'.
Unfortunately after about 7miles of gently driving (less than 50mph) the car started to splutter on accel, I found a place to pull over and stopped engine it had already stalled.
I tried to restart and .... zero
Only 10.4v on the battery again.

Called wife with rescue soccer mum van, spare good battery and solid tow bar.

parralled new batt with old and turned key - not even a click!
Measured 12.5v at yellow wire after ignition switch

I jacked the car and tried to short the terminals on the starter motor but the motor just whined - not engaging with engine
This was with 2nd batt and 12.5v

Car is now home and cool and starter will still not engage.

So, If Joe Bob is still out there? you won dude! STARTER MOTOR!

I will try and back the car into my garage tomorrow and when I get a chance remove the starter motor.
Will see if there is somewhere I can get it serviced

Before I remove starter motor and it is not starting - should I measure volts at yellow wire at starter motor? (will have to get wife to help- or maybe the 4yr old - she is more enthusiastic :rolleyes:

Anything else before removing starter motor?
This is my big chance as before it has been sporadic intermittant and prior to last death did not die for a month of use!

Is something draining the battery (stater motor?) or is the battery just getting drained on starting due to heavy load on trying to get past flat spot?
With a parralelled full battery and 12.5 volts still not engage or start with 12.5v after switch really points to starter motor

Hope to get this fixed soon as i soon get into my solid 6 months work where the girls get minimal maintenance attention, just the occaisional drive if lucky!
Thanks Guys
Ben

Sorry to be right.....:rolleyes:

BTW, never go out with an undercharged battery. It's hard on the alternator. They maintain a charge and are not designed to bring one up when it's low.

Your not gonna hurt the starters feelings.....give the solenoid a good whack. Then try to start it....AFTER fully charging the battery. If you don't have a charger you should. I have two PLUS a tender.

Thanks for not gloating to bad Joe Bob! ;)
I did actualy give it several or more good 'welts' with the factory wheel brace (wheel nut wrench) and then short the terminals with same impliment, but it did not seem to help.
I was a bit cautious as using the factory jack with spare wheel under car for security. I was also cautious of the bitumen road, as it was soft and starting to sink a little and did not feel like getting buried under my car if it burst to life!
I will try again when safely on axle stands and battery fully charged
I do have a reasonable trickle charger and you are right - as I could just switched batteries with my full spare!
I was just so keen to drive her after 3wks of lack of use!
beautiful sunny day and temps about 70F - perfect -almost!
will keep posted
Ben

What's the voltage at the starter?

- Have not been able to replicate this problem and so have not measured this voltage yet.
I may rig up a jumper cable onto this wire so I can measure without being under the car.
I was hoping now the car is 'dead' I can finally do some proper tests however......
went to push car into garage this morning from street parking and she started fine F'ING car!!!! :mad:

Will get car on axles stands this evening and revert.

I have found another weird issue (will add pics this evening)
- the relay next to the 2 fuel pump relays (listed as oil cooler) when removed stops the car firing up?- will turn over but not fire.
Could this relay be for another purpose?
or maybe someone has spliced into one of the wires from this relay!!!
This might have been my stalling gremlin??
Also the relay is a non porsche square type :rolleyes:

if you shorted the battery cable to the other large terminal, you bypassed the solenoid and the motor should just whine, or run. the solenoid pulls the sarter gear into the flywheel.

jump from the battery cable to the yellow wire.

- okay that explains!
unfortunately I could not get far enough underneath to see clearly what I was shorting - very dodgey!
will get car on axle stands tonight and try and get some readings
regards
Ben

Okay, car on axle stands,
Tested thick yellow wire at starter motor with ignition on and have 12.8 volts - same as across battery terminals

tested yellow wire at 14 pin terminal at engine bay left side - same 12.8 volts

Cleaned all pins and slightly spread the pins.

Under dash cleaned and spread pins on 3 - multi pin (5 pins?) plugs including one from starter switch

Car has been starting perfectly when cold again :(

I kinda wish it would not start so I could run other tests!

I guess starter motor removal is next
I have not tried to access the rear allen screw type mounting bolt- is it possible with tranny in place?

Any other tests worth doing before removing starter motor?

Thanks
Ben