Parts Catalog Accessories Catalog Tech Info Tech Forums
 
  Search our site:    
 Cart  | Project List | Order Status | Help    
  We salute a legendary member of the community.
Thank you for selflessly sharing your wisdom with us...
Go Back   Pelican Parts Technical BBS > 1- Porsche Technical Forums > Porsche 911 Technical Forum

Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Jan 2011
Location: Macon, GA
Posts: 609
Garage
DME relay the problem?

Hello Pelicans -

88 Carrera, just returning from about a 100 mile round trip, coming off interstate ramp and engine dies. Everything powered, engines turns freely but not starting. After approx 5-10 minutes and some fiddling with the relay harness it cranks and runs fine... Is this the relay? Have had similar issue when first purchased car two plus years ago, the relay was replaced and fine til now.... does this sound like the likely culprit again?

Thanks

yaz
Old 03-15-2013, 07:56 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #1 (permalink)
muck-raker
 
kidrock's Avatar
 
Join Date: Jan 2009
Location: West Texas
Posts: 2,968
most likely. Only way to find out is to replace the relay.

Just to play "Devil's Advocate", it could also be an intermittant issue with any number of culprits. Hopefully, it's just the DME relay.
__________________
STONE
'88 Cabriolet, using EP Slick 20w50 partial synthetic Snake Oil...just as Rommel intended.

Deny Everything; Admit Nothing; and Always Make Counter-accusations
Old 03-15-2013, 07:59 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #2 (permalink)
Registered User
 
Join Date: May 2003
Location: Detroit (Rock City!)
Posts: 631
Check this...
__________________
'90C4
Old 03-15-2013, 08:52 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #3 (permalink)
Registered User
 
86 911 Targa's Avatar
 
Join Date: Jun 2009
Location: Manhattan Beach, California. Factory Delivery-Original owner-Retired engineer
Posts: 2,856
Dme.

If you can, swap out the relay with another P-CAR owner.

If it's the relay, replace with the factory unit, not the URO.

Ask me how I know.......

Good luck,

Gerry
__________________
1986 911 Targa.
Per Road and Track magazine:
Only in L.A.:
In the window of a bar in Hermosa Beach, California.
"Happy Hour prices during all car chases."
Old 03-15-2013, 09:03 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #4 (permalink)
Vinyl Pimp
 
Joe Bob's Avatar
 
Join Date: Jul 1999
Location: Western Tri-states
Posts: 30,381
I also had an issue with the supplied power from the fuse box TO the DME box. I habitually spin the fuses due to living near the beach. I wore down the contact points on the end of one fuse....intermittent short and it killed the power.

Replaced all the fuses.....some of them musta been 30+ years old...
__________________
**********
Support your Pelican only Custom Graphic guy
73/83/93 RS Cab, 3.6
www.nbdgraphics.com ** also on FaceBook, there are NO BAD DAYS!
WORLDWIDE SHIPPING AVAILABLE!!!!!
Old 03-15-2013, 09:49 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Oct 2004
Posts: 8,399
Yes, an assortment of fuses and a spare DME relay or two are a must have on board.

I also carry a spare oil pressure switch.
Old 03-15-2013, 10:26 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #6 (permalink)
 
Now Available for Ordering:   101 Projects For Your BMW 3 Series 1982-2000  [more info]
Registered User
 
Join Date: Jan 2011
Location: Macon, GA
Posts: 609
Garage
Thanks! To all! I do have a whole packet of new fuses and I will give the ones in a spin while investigating the DME fuse as well.

Porter - As it is the weekend I should have time to see if the one currently installed has a armiture binding problem.

Must confess, my spare is not OEM but I will be placing an order for one today. And an oil pressure switch.
Old 03-15-2013, 10:38 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #7 (permalink)
Registered User
 
dshepp806's Avatar
 
Join Date: Dec 2006
Location: Middle Georgia
Posts: 4,525
Garage
YAZ!

You may as well go ahead and rework the entire fuse block (should you have the time and haven't done it in a while). Chemically clean/treat the copper, clean/tighten the screw areas and re-tension the fuse holders. Let me know if you need any parts, YAZ. You'd be surprised what I have!PM me should you need anything at all.

As to the URO DME relay,....most of the time they just don't/won't last,..not sure what the problem is as I've not autopsied a failed URO DME relay. Others have had them fail right out of the box. Usually (however) they are fine for T/S purposes,..otherwise advised to have the real deal in the glovebox.

Sidebar: Helped a friend last year who was suffering intermittent issues,..he had a bunch of work done (more so) "easter-egging", only to finally discover that the issue (bad connectivity) was within the DME relay receptacle (female) side. Sure had him thinking it was the DME relay for a while!

Hope to see you soon, YAZ!

BEST!

Doyle
__________________
Recording Engineer, Administrator and Entrepeneur
Designer of Fine Studios, Tube Amplifier Guru
1989 Porsche 911 Carrera Coupe
25th Anniversary Special Edition
Middle Georgia
Old 03-15-2013, 11:53 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #8 (permalink)
1984 911 3.2 Coupé
 
Arne2's Avatar
 
Join Date: Jul 2011
Location: Eugene, OR
Posts: 1,881
Garage
Rather than a spare relay, I carry a much simpler bypass wire. Not for normal use, of course, but more reliable in a pinch than a relay.

I've refined the one I now carry some, but the basics are still the same. Description starts in post #23: DME Relay - carry the spare.
__________________
- Arne

"Honestly now, did you spend your youth dreaming of someday owning a Nissan or Mitsubishi?" - Porsche ad from early '90s

Last edited by Arne2; 03-15-2013 at 12:11 PM..
Old 03-15-2013, 12:07 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #9 (permalink)
Registered User
 
Join Date: Oct 2004
Posts: 8,399
yes, but the relay is much cheaper than a DME brain.
Old 03-15-2013, 12:58 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #10 (permalink)
Registered User
 
dshepp806's Avatar
 
Join Date: Dec 2006
Location: Middle Georgia
Posts: 4,525
Garage
I honestly carry two (2) DME relays (not to mention a host of other goodies-all dependent upon where I'm going). It would be good to be familiar with the needed jumper pins should Murphy show up (i.e.,: two brand new DME relays BAD).....wire will do fine there (in the emergency pinch). Additional fusing could be in order, possibly,.. you don't want to be TOO liberal when over-current conditions (uncaught ones)/overvoltage issues can take out a DME. Costly. As Rusnak mentioned "much cheaper than a DME brain".

Again: I carry two.

BEST!

Doyle
__________________
Recording Engineer, Administrator and Entrepeneur
Designer of Fine Studios, Tube Amplifier Guru
1989 Porsche 911 Carrera Coupe
25th Anniversary Special Edition
Middle Georgia

Last edited by dshepp806; 03-15-2013 at 01:43 PM..
Old 03-15-2013, 01:39 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #11 (permalink)
Registered User
 
Join Date: Jan 2011
Location: Macon, GA
Posts: 609
Garage
Arne,

Thanks for this idea. This is just such a irritating glitch.
Old 03-15-2013, 01:43 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #12 (permalink)
Vinyl Pimp
 
Joe Bob's Avatar
 
Join Date: Jul 1999
Location: Western Tri-states
Posts: 30,381
The relay, like a fuse is there to protect more expensive equipment.....relays. fuses, speed/reference sensors, brake pads, 02 sensors etc are wear items.....they need occasional replacement.
__________________
**********
Support your Pelican only Custom Graphic guy
73/83/93 RS Cab, 3.6
www.nbdgraphics.com ** also on FaceBook, there are NO BAD DAYS!
WORLDWIDE SHIPPING AVAILABLE!!!!!
Old 03-15-2013, 01:47 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #13 (permalink)
Registered User
 
dshepp806's Avatar
 
Join Date: Dec 2006
Location: Middle Georgia
Posts: 4,525
Garage
Yaz,

Sure is weird to read this thread again, eh? Forgive me in reposting a piece of thread post #8:

Sidebar: Helped a friend last year who was suffering intermittent issues,..he had a bunch of work done (more so) "easter-egging", only to finally discover that the issue (bad connectivity) was within the DME relay receptacle (female) side. Sure had him thinking it was the DME relay for a while!....

...haunting, eh?

The (your) failed DME relay socket receptacle truly ends up being the source.....along with a flaky DME...

We shall be soldering very soon,.....thanks to Loren fixing the DME,..and ALSO providing us the pin needed to repair. Frikin' A !!!!!!

BEST!

Doyle
__________________
Recording Engineer, Administrator and Entrepeneur
Designer of Fine Studios, Tube Amplifier Guru
1989 Porsche 911 Carrera Coupe
25th Anniversary Special Edition
Middle Georgia
Old 04-18-2013, 02:48 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #14 (permalink)
Undocumented User
 
McLaren-TAG's Avatar
 
Join Date: Oct 2011
Location: Central Pennsylvania
Posts: 684
Garage
Don't be surprised if it isn't the relay or something else electrical power related to the DME.

I think you should certainly look at th relay but I'd suggest doing nothing if and when it happens again and see if it will crank and start once it's cooled off. You could be looking at CHT sensor or speed sensor issues as the symptoms would be similar to what you described.
Old 04-18-2013, 03:03 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #15 (permalink)
Registered User
 
dshepp806's Avatar
 
Join Date: Dec 2006
Location: Middle Georgia
Posts: 4,525
Garage
As mentioned, Loren has corrected an IC failure within the DME. Yaz has ID'd the disintegrated female side of the socket ( I think it's running in a different thread ). So, the final (hopefully) failure point has been ID'd. The replacement part is inbound, as we "speak". The DME has been thoroughly checked out (repaired) by Loren (good-2-go) and we already know about (and will repair) this DME relay Female side issue.

In mentioning this issue (above), I would state that Yaz can get her to crank should there be applied pressure on the socket.....it's quite obvious.

Once we get this addressed,..hopefully we won't have to visit anything further. (although I completely understand what you're recco'g re: the CHT or speed sensor).

BEST!

Doyle
__________________
Recording Engineer, Administrator and Entrepeneur
Designer of Fine Studios, Tube Amplifier Guru
1989 Porsche 911 Carrera Coupe
25th Anniversary Special Edition
Middle Georgia
Old 04-18-2013, 03:44 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #16 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 03:21 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.