Importance of spare DME relay....

nesslar · 08-13-2007, 08:22 AM

Well, it happened, just as you helpful folks have always maiintained it would eventually. So glad I listened to your sage acvice...........I stand in due respect of all your expertise and knowledge. Cheers!
Thursday I dropped my son off for baseball practice, and while I was getting his bag of things out of the trunk (that's up front, you know!

) my '86 Carrera, while idlling in place, "coughed" once, sputtered for just a half-second, then ran just fine. On the way home I stopped at a convenience store and NO START upon wishing to leave for home.

I tried and tried, but the thing just kept turning over but not firing up. I waited between starting attempts, and finally, after a good 30 minutes of anxiety, it roared to life. All this while some drunk 'bastige' kept telling me he'd gladly push me with his truck!

I drove home and put her in the garage.

Saturday morning the car fired right up and I pulled out and parked in the driveway, warmed the car up partially, then shut it down. Later, intending to run a few errands, I hopped in, and once again it wouldn't start, only this time, no way was it going to start.

I pushed the deceased (only comatose actually) into the garage and told myself "Self, it's time to see what little bit you can do to revive a 911."
I fought with the existing distributer cap and replaced it along with the rotor (they really needed changing, looked original) to no avail. No start.....
After feeling somewhat deflated for a little while, I researched exactly where that pesky DME relay was located and decided to try replacing that, too. Fortunately I had recently bought all these things!
Well, under the driver's seat (no need to remove it of course), two little coverplate screws and a nut later, after plugging in the new relay, VRROOOMM! Yes! fixed it!

Mind you, I'm no mechanic, and I didn't stay in ANY hotel/motel the night before, but I did shoot 31 on the front nine yesterday morning! Whoa!!!! And then I birdied no. 10!!!!!!! It became a REALLY good day once the 911 came back to life.
Do those relays usually just die immediately, or do they sometimes take a day or so to completely croak? Also, BTW, the old relay was "loose" inside and would rattle when shook! Surely that ain't right!
Thanks to all the helpful info out there, people! And keep a new spare DME, for God's sake!

KFC911 · 08-13-2007, 08:42 AM

Now go get thee another spare

and drive!!!

nesslar · 08-13-2007, 08:53 AM

Right on! Will have a new Pelican Parts DME relay on its way asap!

azasadny · azasadny's Garage

Excellent!!

bluesky · 08-13-2007, 09:55 AM

i love reading success stories like this one!!! Excellent work!

dshepp806 · dshepp806's Garage

yes,..get that new spare DME quickly..

Best,

Por_sha911 · Por_sha911's Garage

Someone gave me this wise advice:
Not only should everyone have a spare but they should swap it out once before they need it. This will a) tell you that your new spare is good and more importantly, b) you will know how to do it before you are under pressure to replace it on the side of the road at night!

ZOA NOM · ZOA NOM's Garage

Yes, the DME relay (as most relays with soldered connections) will die a slow death, with sometimes different symptoms, since it is actually two separate relays in one. Half provides voltage to your fuel pump, and half sends voltage (current, actually) to the injectors.

Well done.

rusnak · 08-13-2007, 05:31 PM

glory to (a) Ferdinand Porsche, (b) Norbert Singer, (c) Robert Bosch, (d) Ferdinand Piech, or (e) the diety of your choice.

Congratulations, that is a good day for sure!

mike635 · mike635's Garage

Great story! I've had similar experiences with my older BMWs. I think the DME relay is for a Motronic system, true? Is there a similar critical relay that SC owners should have as a spare?

Mike

rootmatt · 08-13-2007, 07:56 PM

Now, if only this forum could be linked to our host's mighty part supply system. A new relay could be sent out automatically. Over the top?

Matt

Early_S_Man · 08-13-2007, 11:47 PM

Steve W. posted a discussion about resoldering the failed relays ... you can use you old one as aspare then ...

DME Relay failure - Prevention and Repair

Here are close-up pics:

PICS - Failed DME Relay

More pics and discussion:

http://forums.pelicanparts.com/showthread.php?threadid=185563&highlight=dme+relay

nesslar · 08-14-2007, 06:53 AM

Quote: "Not only should everyone have a spare but they should swap it out once before they need it."
Exactly what I intended to do! I purchased the new relay only recently, and sure enough the original croaked before I swapped them. Actually I think it's a better idea to have TWO good spares always, because as in my case, the old one was ready to die! Had I used it as the spare, I could have experienced two failures within a short time eventually, maybe while on a drive out in the sticks somewhere!

I think I'll also check into repairing/soldering the old one if it looks salvageable and then test it. Cheap spareand a good little project. Still, another new one (at least one) is on the list.

As for an SC needing something similar, I have come to expect that since those cars are "Super" (somethings) they surely aren't in any kind of danger of becoming a roadside attraction for towtrucks......

Por_sha911 · Por_sha911's Garage

Quote:

Originally Posted by nesslar

I think it's a better idea to have TWO good spares always, because as in my case, the old one was ready to die! Had I used it as the spare, I could have experienced two failures within a short time
I think I'll also check into repairing/soldering the old one if it looks salvageable and then test it.

I just tested the new one and then took it back out and put it in the glove box. When the original died, I did the same thing when the next spare was delivered. As far as repair is concerned, no one has suggested it but I'm wondering if its worth the risk since the cost is minimal and a broken solder will stop you dead in your tracks.

dshepp806 · dshepp806's Garage

the broken solder joint is a dead failure for sure...one must look for this.....make sure all is well in the connectivity world..amen!

best,

Venetian · 08-14-2007, 07:25 PM

It is good to note that the new relay can be faulty as well. I replaced mine with a new one from Pelican after purchasing the car just "to be sure". It failed and left me stranded(similar symptoms as above). I automatically assumed it must be something else since the DME relay was brand new. I managed to get the car to a porsche garage . The mechanic reinstalled the old relay and all was well. Pelican replaced the faulty relay however the mechanic charged me about $100 for his diagnosis.