Tom Loder

I was experiencing issues with the car not starting after driving, say running into a store, come back and it won't start without a thump on the fusebox. I replaced the DME with a URO brand from Amazon to see if that was the problem. That cured the restart issues so far, but now there have been two times when the car will not start up cold. Did I get a bad relay, or should I be looking elsewhere?

One other note is the car seems to have a weak battery, and will need to replace. If I leave the lights on for a bit with the car off, the battery dies. Not sure if this is related or not.

Dan Martinic

It has to turn minimum 200rpm for the DME to activate the DME Relay (fuel portion). When it wouldn't start, was the battery weak enough that perhaps it didn't spin the motor fast enough?

Swenny

Use a 3 way jumper to bypass the relay and see if it starts.

Tom Loder

I will try that.

Though, if I pound on the fuse box cover with my fist, it has always fired right up after. This technique was relayed to me by the former owner who experienced the same problem.

Tom Loder

That could be the case, I'm going to check the battery health today, I will report back.

Dan Martinic

Swenny

Pounding on the cover won't last for long. Somethings loose/misconnected/ corroded,etc. You need to check the fuse box base and the wires going to/from starting with the female on the DME slot. There's a test to check the relay itself to see if it's good. Check Clarks for the test.

Dan Martinic

I got a good tip on another issue that may be part of your relay problem; the official Porsche manual has a warning about the female ends being disrupted by frequent removal / insertion of relays (thanks to user edalenta for the post):

Swenny

No sh*t! Sometimes I wonder what Porsche was thinking with some of the design.

Under dash 924S

Tom Loder

Ok, so I wasn't present when my wife tried to start the car this morning and it wouldn't turn over. I tried later and found the battery is dead. Will replace that tomorrow and see what happens. Thanks for the advice and I will be making one of those jumpers.