crinkle

Guys - I'm brand new to this forum... Hey there!
Hope you can help me out... my Pops has owned a '79 928 since new in VT (its in great condition) and he is currently on a 2-week cruise. The cruise-ship left from near my property so he left the 928 with me and said "Enjoy Her".
Well... since he dropped it off I turn the key and there is nothing, nada, no crank, etc. I've read some tips in this forum on what it could be. And, before my Pops waved me goodbye he said that he felt the connection in the ignition barrel was getting weaker. Sometimes there is no engine turn-over when the key is turned and sometimes it just sparks into life for him after a few attempts.
After reading threads here, this is what i've done (in this order):
1. Replaced the ignition relay with both the interchangeable (windscreen wiper?) relay and with a brand new relay. I can hear the relays clicking when I turn the key in the ignition but the engine won't crank.
2. I can hear the fuel injection system prep (I think) when I place my foot on the brake, switch the transmission into Neutral from Park (its Auto).
3. I've cleaned the ground-strap in the trunk with a wire brush and sprayed with electrical fluid. Its in good condition, there was some light corrosion on the wing-nut but nothing bad.
4. I've volt tested the battery, its strong. There is fuel in the vehicle.
5. Tried jumping from the engine using jump post. Nothing.

Does anyone have any other thoughts?
I'm pretty sure there is no security system cutting the ignition. Could this mean new ignition barrel contacts / barrel / starter motor?

Trying to get it all taken care of so that my Pops has things running well when he gets back from his trip...

Thanks for reading and listening to me! I'm by no means a skilled wrench or Porsche expert, any help greatly appreciated and I'll follow direction

mkriete

No crank is likely an electrical issue. If the fuel pump is prepping, I doubt the issue is the ignition cylinder.

Follow the directions provided by WallyP in the following thread.

https://rennlist.com/forums/928-foru...e-run-etc.html

WallyP procedure will bypass the Neutral Safety Switch. The Neutral Safety switch is located on the drivers side of the AT. There is a connector (I believe 6 pin) in the spare tire well that the neutral safety switch passes though. Check it and make sure it is tight.

The ground for the neutral safety switch is located behind the rear quarter panel near the passenger taillight. It may need to be cleaned.

The Forgotten On

Most likely it is the ignition switch. They get worn out with age and hard starts like yours are a symptom.

Unfortunately you need to take the gauge pod off to get at it unless you want to contort and curse you way through 2 hard to get at screws.

Also, only buy the Porsche part. The Aftermarket Chinese copies are complete sh*t and fail quickly. The Porsche ones last for 30 years

crinkle

Thanks guys. So, process of elimination before changing out ignition switch?

M. Requin

The first thing I would eliminate is the battery. It may appear to be in good condition but not be good enough to start the car. Seems common with 928s, and it is an easy test. Lug it down to Walmart and have them run it on their tester (others may be good, I just like W's test setup). You may be surprised.

crinkle

@M. Requin
I tried jumping at the post. Nothing.

928 DesMoines

I would stop messing with it and wait until your father gets back from his cruise. If he has owned it since new; he knows the car inside and out.
- Just saying. LOL.

Mrmerlin

what did you do exactly at the jumpost?

You can test the starter by disconnecting the 14 pin connector at the jump post and touching the corner pin to the hot post this will engage the starter,

what pin you ask?
OK separate the 14 pin connector.

use the top half ( note this is the engine side of the connector)
looking down at the back of the connector,
it will be the pin thats the closest to the front and the right side row.
just touch the pin to the hot post this should make the starter crank
make sure the trans is in park or neutral.

NOTE if this makes the starter crank then you have issues with the wiring prior to the starter,

if no crank then a resistor could be broken,
there are two white resistors bolted to the inside of the engine compartment ,
they could be on either side of the radiator.
use and ohm meter to test for continuity.
if the resistors are good.


If no crank then the starter needs to be removed and worked on
report back what you find.

you can google 1979 Porsche 928 14 pin connector,
you will add power to pin 14 ,
this is the #50 starter wire.
with the connector connected ,
its the pin on the top half of the connector,
and its at the front of the car and to the passenger side,
its the fat yellow wire.

crinkle

@MrMerlin
I tried jumping the car at the jump post with a booster. Nothing happened.
But thanks for the advice on the 14 pin. I will try that next.

XS29L9B

What I had posted before, seemed to vanish That said, I'll then just agree with above. Don't with the car, seriously. Let your Dad worry about it when he gets back.

Guy

That 14 pin plug is very brittle with age. I would opt to leave it for its owner. Lots of damage can be done by your good intentions

crinkle

Guys, thanks for the good intentions r.e. my Pops. He's pushing 80 and is also not a skilled wrench. He drove the vehicle a good 4-hours to leave it with me and his regular service shop closed down recently.
If its a simple(ish) fix that only requires time, then i'd live to spend the weekend figuring it out.

James Bailey

Get another ignition electrical switch and you can unplug the existing one and pull the plug and wire harness out from under the pod and plug in the new switch....turn it with a screwdriver and see if all is well. Then you can decide if you wish to properly install it. You can also drive it like that using the key to unlock the steering column. So your father can take it home !
If the connection piece in the barrel of the locking assembly is indeed worn that requires a bit more work to get the lock cylinder out. Pod removal etc.

928 DesMoines

Did you follow the thread regarding Relay XV from the thread linked in post #2. It seems to describe your problem pretty close. Might want to re-visit that one.


You tested the battery? Did you pull it and put a charge on it?


And just one more disclaimer: Before you get too deep; wait for Pops!! 80 years old or not, it might be better if you two work together on it.

Landseer

Temporarily replace ground strap and try it.
We are seeing them fail inside, beneath the plastic insulation.