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Testing the 3.2 DME ?
Posted: Wed Apr 16, 2025 7:42 pm
by 911hillclimber
Anyone know somebody who can test my dme for functionality?
Re: Testing the 3.2 DME ?
Posted: Wed Apr 16, 2025 10:43 pm
by Nine One One
Re: Testing the 3.2 DME ?
Posted: Thu Apr 17, 2025 8:58 am
by 911hillclimber
Thank you!
Saw that last night and another how to test the engine pair of sensors by reading the pin-outs on the DME connector strip while cranking the engine.
If i have time today, will be going through all this.
Checking for cracks in the DME relay is quick and easy.
The above is 944, but i found a similar video on youtube for the same but the technician said it covered the 1985 3.2 911 engine DME also.
Re: Testing the 3.2 DME ?
Posted: Thu Apr 17, 2025 12:25 pm
by 911hillclimber
Just tested my 2 DME relays, one from 1985 and the other from 1995.
Both check out to that test.
Got a nice new one coming...so will have 3 good DME relays!
Time to measure the two engine sensors, a different kettle of fish.
Re: Testing the 3.2 DME ?
Posted: Sat Apr 19, 2025 4:54 am
by Nige
Test the sensor by all means, but if you have never replaced them then do so. They're not too costly and relatively easy to replace.
You don't need the spendy gen Porsche ones as they're used in a bunch of other stuff. Can't recall but there are some cheaper BMW versions.
Re: Testing the 3.2 DME ?
Posted: Sat Apr 19, 2025 6:44 am
by 911hillclimber
I changed one some time ago, the other is still 1985…
Measured the resistance of both at their plug end by the fuel filter.
Range is between 600 to 1600 ohms.
One was 860 so good.
Other was about 15,000 and the meter was wandering all over the place, so deemed duff.
Cheap one from design911 awaited.
BMW one at a guess, the cars use the same part.
Might arrive Wednesday next week, even Tuesday.
Awkward to fit iirc!
Re: Testing the 3.2 DME ?
Posted: Sat Apr 19, 2025 1:51 pm
by sladey
Depends where you’ve put it. On a 3.2 it’s under the passenger seat and if you take the seat out it’s a doddle
Re: Testing the 3.2 DME ?
Posted: Sat Apr 19, 2025 5:18 pm
by 911hillclimber
The sensors I'm dealing with are both on the side of the engine/box triggered by the ring wheels.
I had to remove the hot air ducting and the NSR damper to get at the oneiirc years ago.
I hope the one to be changed next week will be a bit easier as it does not need careful adjusting to get the 0.8mm air gap.
The actual DME and it's relay are under the passenger seat where Bob Watson and Paul Brock bolted it down in 1995.
Re: Testing the 3.2 DME ?
Posted: Sun Apr 20, 2025 6:15 am
by sladey
Sorry yes I thought you were talking about the DME relay. yes the other two aren’t easy to get at - it is doable though
Re: Testing the 3.2 DME ?
Posted: Sun Apr 20, 2025 1:41 pm
by Nige
Just remove the whole bracket with the sensors, setting the gap is easy enough with piece 0.8mm feeler lightly stuck to the end of a sensor. Fix the bracket, remove the sensor, toss the feeler gauge, refit the senor.
Yeah, I removed the bottom shock for easier access and the heater duct.
If the sensors have been in for yonks I doubt they'll just easily slip out of the bracket. I did get one out in one piece, the other had swollen that much I just drilled it out.
They might not be the issue yet, but fingers crossed.
Re: Testing the 3.2 DME ?
Posted: Mon Apr 21, 2025 4:48 pm
by 911hillclimber
Hope you are wrong!
I have found 3 companies who deal with ECU's, but who knows what they will say to a 40 year old DME unit...
With a bit of luck the parts will be with me on Wednesday and it will spring into action every start.
My luck is NEVER that good.
Re: Testing the 3.2 DME ?
Posted: Tue May 13, 2025 2:39 pm
by rich73
Re: Testing the 3.2 DME ?
Posted: Tue May 13, 2025 3:48 pm
by 911hillclimber
Thank you for the post.
IB have been very helpful looking into this issue that is fully resolved!
DME from 1985 with the first Bob Watson chip fitted still 100% good.
