924Board.org

[Kerry]

Hi, my husband and I have a very prem baby (24 weeks) in hospital (90 mins away) and need to find out what is going wrong with our 1980 924 so we can get to see our son every day. Below is the problems we've been having, please can anyone suggest what my husband needs to check/do bearing in mind his mechanical knowledge is limited.
1. Started out for hospital with wipers and heater going after about 3 mile volt guage started dropping and elecs slowed down. Turned round to return home by time arrived volts read 0 on guage. Turned car off then couldn't restart due to flat battery.
2. Recharged battery overnight and managed to get her to a garage with volts dropping slowly. Was advised to get new alternator as battery checked out ok. Put new alternator on next day but still lost volts and battery draining flat.
3. Back to different garage where found new alternator faulty so mechanic kindly repaired and refitted it (repaired old one also!). Volt guage was nicely back in green again.
4. All fine for 2 days then car wouldn't start!! Battery fully charged, turning over but not firing. Managed to easily start her with bump/push and she made the journey to hospital and back again with no problem starting.
5. Next morning wouldn't start again unless given a push up the bum! Coming back from hospital in dark had to use lights, heater and wipers which caused volt guage to drop to 12 at 2000 revs and above and 10 when idling at 600 revs. Volts go back up to about 13 when moving with no elecs on.
I think thats everything....please can someone help point us in the right direction as to whats up with her.[/b]

[Paul]

Welcome to the board and congrats on the new addition to your family.

I'd check the following (I'm including obvious items just to be thorough):

Alternator belt tension

Alternator bushings

Alternator ground wire

Battery clamps

Small red wires that attach to the + battery clamp

Alternator wiring from the alternator to the starter and from the starter to the battery.

Ignition switch (it's a $10 part)
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[Chrenan]

Congrats on the new baby, sorry to hear the arrival was early.

Paul's info is bang-on, as usual, he is very experienced with these cars.

Erratic gauges are often a grounding issue, the engine ground on the exhaust side of the motor which connects to the large frame rail is often a culprit. The ground wire can come loose or just become suspect with age. Easy to replace and a cheap as well.
_________________
1987 951 - M193 Version for Japan

[Kerry]

Thank you for quick reply and the congrats. . The kind mechanic at the VW garage checked the first 3 on your list. Will get hubby to check the rest. After looking round the forum, I was wondering if there is a timing problem and if so can that cause any of our problems? Should the revs be as low as 600 when idling (excuse my ignorance if thats a daft question...I am blonde after all )?

[Kerry]

Thanks Chrenan, will check that also. Hubby becoming more like a mechanic everytime he comes out from beneath the bonnet He's even got the wounds to prove it, he now knows how hot the manifold gets!

[joecitizennn]

does not sound like a timing problem. Kind of odd that the car cranked while refusing to fire at one point, but began running with a push start. Has that happened more than the one time you mentioned?
_________________
87 924s
88 924SE gone
447 hp cgt clone
87 924S gone
84 944 sold
83 944 sold
89 turbo S LSD, ABS etc
86 951 white rocket
85 944 sport everything.
84 944 sold.
87 944 sold

[Lizard]

it should idle around 850 rpms,

With the volt guage dipping when you turn the lights and other accesories on, that is normal, with the car idling, turn everything on and measure at the battery with a volt meter, if it is below 13 V, you have a problem.

regarding starting it requiring a push start, I would mimic Paul's suggestion in replacing the ign switch first. after that it is checking broken wires, etc. However next time it happens, have someone listen to the fuel pump while cranking, is it coming on when you are cranking?
If it is then the issue is getting power to the ign module when cranking the car (circuit 50 iirc) there should be a wire running from the starter to the ign module which does this. Check there as well (will need a haynes wiring diagram).
_________________
3 928s,

[Smoothie]

Also, (the mech should have done this, but..) check the charging system light in the dash. With ignition switched on, but engine not running, the light should be on. It's part of the "exciter circuit" which tells the alternator to start charging. If that bulb is burnt out or otherwise not working due to faulty wiring, etc., the alternator won't go into charge mode.
-And if the light stays on while the engine is running, that indicates a problem as well..
_________________
"..it's made in Germany. You know the Germans always make good stuff."


'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

[Ozzie]

The charging system sounds ok and volts will drop under load to around 12 as you said.
my 2c.- Battery is cactus.

Cold weather destroys batteries.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[Chrenan]

[Tigger937]

[Buwani 931]

[Kerry]

Thanks to all who have replied, very much appreciated. We do also have another more practical family car....a '68 morris minor , unfortunately she's waiting patiently for a new engine . As we never really travel more than 10 miles, the 924 (not turbo) was never really a problem even with 4 children...hubby loves car so much he'd do 2 trips!! Regarding child restraints, our local policeman told us the 4 point harnesses in the rear were safe and legal. Obviously if we do ever put a baby seat in, it will go in the front passenger seat. Plan is to get morris back on road, sell and get another car (Datsun 280ZX maybe )
Joe asked about the bump starting....it only needs bumping once in the morning then starts up fine after that until its been left standing for more than about 5 hours. However it started first time this morning after standing all night, could it be a cold start problem as weather was much milder today. [/code]

[joecitizennn]

I would not think that having to bump start the car every morning was odd, if the reason behind it was an inoperative starter. But you said the starter cranked the engine fine, the car just would not fire up. So why then would it decide to fire with a push start? If the engine runs with a push start, then it should run from the starter cranking it.

I am not up up on early 924 electronics, so maybe someone else can come up with a reasonable explination. Is it possible that the cranking of the starter causes such a voltage drop that the ignition does not have enough juice to fire?

Have you checked your spark when trying to crank the engine with the starter? It is simple to check, and the color and size of the spark can tell you alot about the health of your ignition system.
_________________
87 924s
88 924SE gone
447 hp cgt clone
87 924S gone
84 944 sold
83 944 sold
89 turbo S LSD, ABS etc
86 951 white rocket
85 944 sport everything.
84 944 sold.
87 944 sold

[RC]

Joecitizennn wrote: