Continuing electrical problems....... Help!

[B'gad]

i have driven my 1989, 22k mile 993 tt 4 times and on each occasion have had to either be recovered or jump start it to get home.
it has just come back from OPC Swindon with a new battery and new alternator. After delivery to home, it sat in my garage for 7 days on trickle charge. I have just driven it 20 miles and it didn't start. I used a boost pack and it got it going. I am about to throw in the towel on classic Porsche after just a few months of ownership and go back to something old and English!
please, any ideas why it might keep losing charge?

 

[T911UK]

When you say "didnt start" did it crank? Nothing, crank slow? More info needed really...........I guess you mean 1998 too?

 

[noblewilson]

If the voltage is still high, at least over 12.6 volts, then it would possibly point to a bad earth connection! I would be checking that out first.

Best of luck

 

[B'gad]

Apologies, it is a 1998 and it did not crank at all. All dash lights lit up. It did start when hooked up to a battery booster. At the start of the journey the battery was on over 13V.

 

[nickgardner]

Can't speak as to the problem, though suspect good example of why low mileage not always a good thing. However these cars are as a generla rule ultra reliable and not prone to gremlins, electrical or otherwise. My advice would be to preserve a nd get it so ted or you will miss out.

 

[T911UK]

Check the battery connections are tight, it sounds like a bad earth or connection.

 

[B'gad]

Thank you. Checked the connections and all good. I have yet to check the earth.
I wonder if it could be a faulty immobiliser? Its reaction time is very very slow when disarming it once the car has sat unlocked for a while. If i press 'unlock' then turn the key, nothing happens. If i press 'unlock' and wait for 5 seconds (which is ages) then turn the key it seems to fire up. When i try to start the car and it is dead, i have a mental short-circuit and just start jabbing buttons so can't be sure.
I will try to rationally discount this theory and report back.
Thank you for all of your answers so far, especially the suggestion to persevere. I love the car, it looks and sounds great and goes like a rocket.... when it starts. I'll keep going for a bit.

 

[B'gad]

Hi Maurice
Apologies if i have driven you to drink...
I have 2 fobs, both new from H&P via OPC a few weeks ago when it was in the garage for the 2nd time. The batteries are brand new.
The battery booster is a svelte Lithium power pack with a couple of bulldog clips on it that will jump-start a Challenger MBT should it be required. It may be a coincidence that the jump-start coincided with my PA1000 eventually waking-up and allowing the car to start.
I plan to fiddle about with the car over the weekend close to home instead of the epic drive over the Alps that i was planning. (just kidding). Thank you for your help - don't be cross - i actually do want to keep the car, my wife tells me its much more 'metro' than an old AM V8 Vantage! (That's a good thing nowadays).

 

[Gordon Attar]

Hi, there are so many wires in that car you could have a failty earth;, mouse damage to a wire, arcing in the engine area, immobiliser issues etc etc.
My advice is take it to Northways near Reading 0118 971 4333. Ray Northway used to have a 993 tt, there seems to be a 993tt in their everytime i visit and they looked after mine. Paul the chief mechanic is top notch will sort out any electrical issues and then you can enjoy one of the best and most rewarding cars ever.

 

[szklarek]

+ 1 for Northway's they really know their stuff and you'll get sound advice.

 

[Chrissss81]

Does this only happen after you were driving for a while?
Another possibility in this case is that the battery is not charged while you are driving for some reason.
Check the Voltage when the car is running, if it is around 14.4V with a fully charged battery then the alternator works fine.
If not, check the voltage when the engine is switched off and then when the engine is running.
Switch on all electrical components (Head light, main beam, fog lights etc) when the engine is running and then measure the Voltage.
If the Voltage with a running engine is lower than with the switched off engine, there may be a problem with the alternator as the car electrics are running on the battery rather than on the alternator.

Good luck

 

[B'gad]

I'll be having a chat with OPC in the morning!
I think that through trial and error, i have narrowed it down to the PA1000 immobiliser.
It seems that if you turn-off the car, remove the keys, lock it and come back after a few minutes it starts every time. If you do not lock it, the auto-immobilise kicks-in and when sitting in the car, you have to press the unlock button. If you try to turn on the ignition before the PA1000 has scratched its bottom, had a fag and a coffee - about 4/5 seconds, it is still immobilised and whats more it then cancels the unlock command. You then have to wait a further few seconds, lock the car while you are sitting in it, wait a few seconds, unlock the car, wait a few seconds, and then, and only then, will it start. This it seems to do reliably.
The key to the problem i think is for me to always lock the car once i've got out, even if i'm just going to be out for a short while.

This may of course prove in the fullness of time to not be correct, and i have an intermittent battery/immobiliser problem that only doesn't work when i'm further than 20 miles from home.... we will see!

Thank you everyone for you help, expertise and words of encouragement, and Maurice, perhaps i'll take you up on your offer to buy it for £15k if you catch me at the right time whilst stranded!!

 

[Chrissss81]

Chris, he's got a new battery & alternator from the gleeful OPC !

cheers, Maurice [&:]

Oh, sorry, next time I'll read the post properly

 

[Gordon Attar]

If you are talking to the OPC make sure it's someone who was fitting the systems in the 1990's as they were OPC fitted. They really arent the place for dealing with 20 yesr old cars with problems. Also there is an in built error system that in involves the number of flashes that defines the error.

 

[IndischRot]

I'll be having a chat with OPC in the morning!
I think that through trial and error, i have narrowed it down to the PA1000 immobiliser.
It seems that if you turn-off the car, remove the keys, lock it and come back after a few minutes it starts every time. If you do not lock it, the auto-immobilise kicks-in and when sitting in the car, you have to press the unlock button. If you try to turn on the ignition before the PA1000 has scratched its bottom, had a fag and a coffee - about 4/5 seconds, it is still immobilised and whats more it then cancels the unlock command. You then have to wait a further few seconds, lock the car while you are sitting in it, wait a few seconds, unlock the car, wait a few seconds, and then, and only then, will it start. This it seems to do reliably.
The key to the problem i think is for me to always lock the car once i've got out, even if i'm just going to be out for a short while.

This may of course prove in the fullness of time to not be correct, and i have an intermittent battery/immobiliser problem that only doesn't work when i'm further than 20 miles from home.... we will see!

Thank you everyone for you help, expertise and words of encouragement, and Maurice, perhaps i'll take you up on your offer to buy it for £15k if you catch me at the right time whilst stranded!!

You might wish to ask Hamilton Palmer the cost of a new PA1000 circuit board or simply describe the symptoms to them to see if it's a known failure mode...

 

[Stewart Rix]

A new circuit board is around £150 if I recall correctly on an exchange basis from Hamilton & Palmer. Removal of the old unit is theoretically straight-forward if you have the correct tools. You'll get new fobs and red master too.