924Board.org

[garethjrichards@gmail.com]

I need some help.

My 1983 924 N/A got a service about a week ago. Now it has this intermittened starting problem.

I'll get in turn the key and the engine will turn (hard start i think is the word) but not spring to life. It seems that the spark plugs aren't starting when this happens. But after push starting it comes to life and runs perfectly (spark plugs are sparking like normal after the push start).

I say its intermittened because I'll have the car running and I'll turn it off. When I start it again it works (luck?) then try it again but leave it to stand for an hour or two and come back and it starts. So I think, "Okay maybe it was a once off thing". The next morning I come to my car get in and it doesn't start and I have to push start it again.

I sent it to an auto electrician but he doesn't want to work on the car because he doesn't know what's wrong with it (idiot). He suggests I send it into a porsche specialist (which sounds like I'm going to have to take out a loan). Any ideas?

[Smoothie]

From here it sounds like maybe a battery problem. -And/or a drain that's killing it overnight.
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"..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

[garethjrichards@gmail.com]

Thanks smoothie you just reminded me I forgot a small (possibly large detail) in the story. I can push start it but I can't jump start it from another car's battery (tried it a few times). But when I did a trickle charge over night it started in the morning. Would it still be a battery problem if I couldn't jump start it?

[924RACR]

If you can't even jump start it, very likely a bad cell or two in the battery.

I trust you have already checked and cleaned your grounds?
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Paul]

I'd also check the wiring from the battery to the starter and the starter itself.

Have you been losing any coolant lately?
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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.

[garethjrichards@gmail.com]

Coolant? No! During the service the mechanic did a pressure test and said their was no leaks and I haven't really had a problem with loosing coolant. But I'll check the wiring between the starter and battery.

[Aussie931]

Could also be a dodgy fuel pump relay connection. I had a similar problem which was caused by carbon build up on the relay board pins. Once I cleaned them up and it started every time.
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1979 Series 1 924 turbo

[garethjrichards@gmail.com]

bit of an update:

I sent it in to the specialist problem was that when they got the car it was perfectly fine. No problems for them at all and it came back to me in working order. I've been driving it without problems for about 2-3 weeks.

Until now, Yesterday I decided would be the day that I finally fix that leak in the battery well. Took the battery out, cleaned the mess up, and put down some seamsealer (which worked really well). I left it to dry overnight and this morning I put my battery in and tried to start my car.

Well, it didn't start (just like before). It seems to be hard starting again.

I also noticed a leak in the fuel accumulator (like the diaphram is broken) could that be the problem?
Battery?
Alternator?

[emlynbeagler]

Something similar happened to my 931 last year. In my case, the car would normally start from cold, but after the engine had heated up it would need to be left around 45 minutes before it would start again.

I had no problem with the battery or electrical system (except for running the battery flat, cranking the engine and cursing the car every time I had this problem and needed to get somewhere in a hurry.)

The cause was insufficient fuel pressure on starting. A new fuel accumulator and replacement of any fuel pipe that looked old and worn cured it. To see if this is the issue with your car, pressure-test the CIS after the fuel accumulator.

Be prepared for £££ (or at least ££).
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1984 924 Turbo
2017 Alfa Romeo Giulia Quadrifoglio
2017 Isuzu D-Max
1974 Moto Guzzi 850T

[Smoothie]

[garethjrichards@gmail.com]

Ok, Well, Swapped my battery with my wifes and my car started first time. So I was like "New battery".

Checked the current (car off) and it shot up to about 400mA and then after 20 seconds dropped to 40mA and stayed there. Not a problem if it stays at 40mA so went to get a new battery. Put the battery in. Connected the wires up. And it just does what it usually does. Crank but no fire.

I noticed a cut cable that was just twisted back together on my ignition coil and some green powdery buildup on the copper cabling (not much though). Could it be my wiring?

Also this only happened after a full service. Is it possible that in the service a standard part was replaced that would have this affect? Spark plugs (I'm doubtful)? Oil too thick? Now I'm just jumping to conclusions.
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Gold Porsche 924 1983

[Rich H]

Fix the twisted together wire on the coil.

Make sure that the coil is getting enough voltage. It could be that the starter circuit for the coil is bad so when cranking the coil is only getting "run" voltage (6V?) instead of "start" (9V?) This will make is hard to start off a battery but a push start will use the "Run" circuit. This is to make a bigger spark when starting but overloads the coil (briefly) which isn't a problem, when runnign the engine needs less spark energy to fire.

Depending on the wiring spec on your car you will either have resistance wires or resistors near the coil. Check the manual for the resistances you should expect on them.
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

[924guy]

short answer, rebuild positive battery cable....

long answer: besides bad grounds, the positive battery cable on an n/a (this is a 924 turbo area , but thats okay ) can be a major source of headache.
heres why: the cable is in a high heat area, which over times degrades the heat insulator and the cable itself. as time goes by, the cable corrodes and builds internal resistance, becoming less of a conductor, sometime to the point of total failure. Bare spots on the cable (or thin spots in the insulation) can also ground out against metal parts (bad) also causing pre mature battery failure and other related failures. the cable can also move around, so at times it seems okay (not making any contact or grounding) and when it shifts, results in a problematic spell. then itll shift back and be okay for awhile again... enough to drive one loopy if you dont know about the potential problem area.
the cable also has a branch wire or two, been a long time, and is NLA . So you cant just go down to the parts store and get a drop in replacement. you can get the components though, and build your own without too much difficulty, dont forget the heat resistant wrap. or you can pull yours out and have your electrician build one for you using the original as a template.
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Eric
78 924
82 931 SE "smokey"
99' VehiCross
Y2K Honda Insight
http://www.cardomain.com/id/924Guy
Performance by Pasha

[tuurbo]

I've had spark jump across the solenoid connections. Try lube-ing them with like an insulating grease or equivalent. Replace power cable is a good idea too.
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

[garethjrichards@gmail.com]

Well, I finally gave up and sent it in to the shop. Still waiting for it to come back. From the sounds of it though they found the problem and it seems 924guy was right with that last comment. The positive cable to the alternator and starter was almost completely gone in a small area that runs over the exhaust.
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Gold Porsche 924 1983