Menu toggle

DME relay

944cabby

944cabby

New member
Fitted a new DME relay yesterday which came to £26 with post from the porscheshop.Seems more positive on startup now over the past couple of weeks she was getting quite sluggish until warmed up.
 
My 944T died on me in a garden centre car park a few weeks ago!! I had to be towed (most undignified!!) in to my Porsche specialist, it was the DME relay, he popped a new one in and away it went. Cost £20.
Harriet
 
ORIGINAL: millisland

My 944T died on me in a garden centre car park a few weeks ago!! I had to be towed (most undignified!!) in to my Porsche specialist, it was the DME relay, he popped a new one in and away it went. Cost £20.
Harriet
Click to expand...

How was it running up to that point - was she starting ok?
 
How was it running up to that point - was she starting ok?
Click to expand...

She was absolutely fine, gave no hint of anything wrong. I drove over to the garden centre on my way to shopping in Swindon. Stopped in the car park, had something to drink, etc. Came out to start the car and carry on my journey and the engine just would not turn over!! That was it.
Harriet
 
After two 'non starting' experiences with my S2 which I blamed on the blue topped sensor under the inlet manifold ( the second 'experience' was 'cured' by squirting easystart into the loosened rubber induction trunking). Went to Le Mans this year, got off the chunnel, stopped at the first petrol station, filled up, guess what? It would not start! Turned over ok just would not fire (and no whirring from the fuel pump) wishing that I had taken the advice to keep a spare DME relay in the glove box, I took the said relay out of it's slot, shook it, it rattled! I banged it against my hand, popped it back and she started instantly and continued to do so for the next four days. Needless to say I bought a replacement as soon as could on my return home. 911 & 911 etc world did an article on DME relays a while ago and observed that 'dry' solder joints on the relay's PCB often had brown crystals around them, guess what two of mine did. I've re-soldered them and am keeping it as aspare.
 
DME's are one of those things you just forget about, til it happens to you...

Better safe than sorry, I've just ordered one from you Andrew - as it's an "improvement over the original", am i better fitting yours and keeping the original as the spare?

Matt
 
curious coincidence??? my car is currently beached in a car park near work! I got in ready to drive to Birmingham yesterday afternoon...nothing, just a click or a clunk (not very good at describing noises) but not even turning over. Could this be the DME? It has done it once before, but seemed to cure itself. Any suggestions gratefully recieved
Matt
 
My cab did it. Cleaning the starter contacts fixed it but the starter was slow (even for an S2) so I replaced it in the end. It was about £130 exchange and fitting is next to nothing.
 
Thanks Fen - that's encouraging.

It had stuck once before but freed itself, so i guess it was only a matter of time. I've had it towed to RGA, a specialist in Vauxhall who i used for my last 951, he assured me that it's a half hour job. I had horrible images of hours and hours of labour...
 
Q) If my car won't start, is turning over, spark plugs smell of petrol but aren't sparking... would i be right in thinking it couldn't be the DME relay as that controls fuel flow?

If i am right it then i'm guessing that leaves coil or Engine Management electric gubbinge.

[p.s. despite the general nature of my posts, my car does work sometimes! [:D] ]
 
SCZ has the newer DME courtesy of Bert...but occasionally STILL wont start easily when warm. The whole fusebox was replaced a year and a half ago (set fire to original!). Any ideas...
 
The DME relay is not to blame if there is fuel to the cylinder - as I understand it the "DME relay" is what on other cars is called a fuel pump relay.
 
It does shut off the fuel pump if the engine stops turning (or at least: it did when Porsche built it, but many are 'modified' when alarms and immobilisers are fitted), but its a double relay inside one case: one relay operates the DME and the other the fuel pump.

Simon
 
Are you sure it controls the DME? From what I can see its a relay to control the fuel pump with another relay to provide a backup shut-down of the fuel pump.

One of the coils seems to be operated by the DME and switches the live feed to the fuel pump but its weird because one of the terminals of the coil has two connections to the DME. Perhaps this is some kind of shut-down so it can ground its own live feed to the coil. The other coil is operated by another signal (not sure what) but it seems to short out the live feed that supplies the fuel pump to one of the terminals of the other coil. I can only presume that the terminal is the ground terminal so is effectively shorting out the live feed to the fuel pump. Its a little confusing without knowing what its actually meant for and what each of the terminals connected to the DME is doing.
 
Now youve got me thinking, because this is something that Ive 'known' for almost 20 years, if you know what I mean? Its certainly known as a 'fuel pump relay' in series one cars.....

I'll read up in the morning.
 
You must log in or register to reply here.

Posts made and opinions expressed are those of the individual forum members

Use of the Forum is subject to the Terms and Conditions

Disclaimer

The opinions expressed on this site are not necessarily those of the Club, who shall have no liability in respect of them or the accuracy of the content. The Club assumes no responsibility for any effects arising from errors or omissions.

Porsche Club Great Britain gives no warranties, guarantees or assurances and makes no representations or recommendations regarding any goods or services advertised on this site. It is the responsibility of visitors to satisfy themselves that goods and/or services supplied by any advertiser are bona fide and in no instance can the Porsche Club Great Britain be held responsible.

When responding to advertisements please ensure that you satisfy yourself of any applicable call charges on numbers not prefixed by usual "landline" STD Codes. Information can be obtained from the operator or the white pages. Before giving out ANY information regarding cars, or any other items for sale, please satisfy yourself that any potential purchaser is bona fide.

Directors of the Board of Porsche Club GB, Club Office Staff, Register Secretaries and Regional Organisers are often requested by Club members to provide information on matters connected with their cars and other matters referred to in the Club Rules. Such information, advice and assistance provided by such persons is given in good faith and is based on the personal experience and knowledge of the individual concerned.

Neither Porsche Club GB, nor any of the aforementioned, shall be under any liability in respect of any such information, advice or assistance given to members. Members are advised to consult qualified specialists for information, advice and assistance on matters connected with their cars at all times.

Porsche
Lockton
Pirelli
Officially approved
Oracle Finance
WEX Esso
Collecting Cars
Back
Top