Best Solution Re Defective 924S DME

[pc100porsche]

My wrench advises I need a NEW or REBUILT DME for a 1987 924S.

Any supplier recommendations from personal good experiences ?

[originalowner]

Cheapest is likely a used or verified DME. Even if your mechanic is wrong, at this point in the life cycle of these cars, a backup DME is a good thing to have on hand.

There are more modern alternatives if you want to spend more.

[pc100porsche]

Anyone have experience with Force 9 DME ?

[pc100porsche]

Anyone have experience with Force 9 DME ?

[Monkey Wrench]

an advantage of having the right service person is that if they work on porsches , they could swap the DME and PROVE it needs a new one by seeing a change. I dont see a valid porsche mechanic not havign ccess to a spare for testing purposes, that way if it's not that they dont charge you for it. I bet if they try to swap it they may be mistaken but still want to charge you the cost of the part ebven though it was misdiagnosed.
do you know if he chacked the grounds, its not a bad DME relay with bad contacts is it? if the hot wire isn not making good contact (a voltage drop) that can cause issues. If the DME relay is suspect or just old, Id' start there.

i just changed the fuel pump relay in my volvo , the old one works ok still , I dont want a voltage drop created by burned contacts, or a breakdown, in the porche that feeds the DME and fuel pump or so I think.

Its lightweight so the old one can go live with the spare tire.
The DME relay is know to cause issues so its worth replacing and having a spare, there are some solid state ones, that's an option.



if you are up for a little soldering and want to try to save money, you can try swapping the capacitors as ( in general) they are known to fail due to age and they only cost a few cents each , there are probably only about 3 or 4 in it.

DME boards (or ECU's ) can be damaged by electrostatic shock and by hooking up the battery backwards and could fail , but sometimes a mechanic that is looking for a reason can blame them ,incur a big expense, and not solve any issue.

You can look for others from parts cars or ask here.. I replaced the one in my ford van from the rock place. it was a reconditioned one, no issues.

I looked up yours at the same source and it's out of stock part number BSE EM6027 you can set an email reminder for when and if they restock it, and hope for the best. if you have time to.

I tried replacing the caps in the one in my van, I found that i could clip them off just above the board, careful they can squirt the electrolytic oil in your eye, I just take side cutters and clip them right through about 2mm from the PCB to leave a bit of end on the leads.

Then take a pin and wrap the leads of the new one around to form a coil like a tiny spring then crimp it over the stub lead and solder that . If one preferred, they can break the heat conductive putty , repair the board on that side and then replace the heat putty.

I'd avoid that by working on the side whit the caps exposed. just leave enough to solder to. also electrolytic caps are polarity sensitive, the line indicates negative do not install them backwards or they will blow straight away. best to mark the board and take pics before you go clipping the caps off. or you wont know which lead was positive its indicated on the new cap, look for a line, looks like an arrow, that's negative.

maybe you won't do it but maybe someone else wants to. you might find a local electronics guy. I understand you may not be up for all that stuff.

I made a little goof up and accidentally clipped a tiny corner off a transistor then gave up, was a little disappointed in myself, and and ordered a rebuilt replacement.

I've been meaning to try to salvage a transistor from a known bunned one. I don't think the other parts are very weak against time, capacitors do fail with age. they are old enough to be unreliable or bad.
that maybe all that's wrong with it, some caps worth under a dollar each. but that's a bit of a gamble , no guarantee there. The little chips with lots of pins, leave them be and dont expose them to static shock, or touch them. common practice to wear a grounded wrist strap to discharge yourself to prevent that.

upon examination of the one in my van, looking carefully I could see a little stain patch below some capacitors, now that is a good visual indicator of trouble. look at the board carefully ear each capacitor, they look like little tiny tin cans.

the caps can leak, the leaked oil * which might be PCB's * (so consider that oil hazardous)
it can stain the board ( look close, take pictures) If you can see a little patch near the cap, that is a bit discolored, that's a telltale sign the cap has gone south .

the caps can be checked , there is a meter for that, but they are cheap so why goof around, the value in microfarads is on them so it'll say something like 4mfd ( look for the value each of yours has) and then they will state the the working voltage so it may say 16VDC
that means the caps are rated to withstand up to 16 V. it could say WV ( working voltage)

any repair like that is a bit of a crapshoot but it may be the failure point too, so you can perhaps have someone that does electronics work do that for you , its actually really easy just a bit tiny you need a little soldering iron, not a big Weller heatgun type. a small pencil iron is ok.

for the self driven and cheap people like me,, well that costs under 5 bucks so not a huge gamble if you are ready to replace it anyway?

fixing stuff with your wallet is easier yet, so you can decide on your direction .. and I know you may or may not want to wait or muck about, you have choices.
good luck ! let us know what happens OK ?

[TibetanT]

Force9 sells the SS DME Relays.
These are very, very good relays.

But if you are looking for the ECU/DME brain there are very good repair listing for Porsche members within the Panorama magazine we get each month. Most will test for free, you pay shipping. Also, I know of Pelicans that do repair these as well.

If you are NOT a PCA member, then let me know via PM where to send you addresses and phone numbers of these repair electronics.

Hope this helps.