divil

My DME was also fine after the wetting, once it dried off.

That sounds a lot like the normal drain path. There's a little opening on the passenger side of the battery box - water drains through there and comes out where you described. But if there's a hole in the bottom of the tray then at least some water will definitely get into the passenger foot well which is where the DME is. In my case you could feel it on the carpet.

nelso419

Yeah I thought it was a normal drip path. But for 40 mins?

nelso419

Got the 944.2 and I'm at work so I don't haven't had time to dig real deep. But a cursory check by the DME is that it feels pretty dry, (but its has been sitting all weekend) and I can't see any fraying on the sensor wires when I pull back the boot but I hadn't looked at anywhere other than the heads. So I guess I have 3 routs to go.
1) water on the DME
2) bad reference sensor harness
3) bad DME relay

For #2 does anyone know how to check that without pulling the wire out? And how difficult is that to do?

Jfrahm

Why do anything other than jumper the DME relay first? It is a very common problem particularly with the chunky old 944 part number DME relay. I've also read that the URO brand cheapo new one is dodgy as well but have never tried one.

divil

I don't think you want to go pulling the harness out, and it's unlikely to tell you anything if you can't see a problem at the connector anyway. If you are getting a signal at the sensor's connector, but not at the DME connector, then that obviously points to the harness. But that's difficult to pin down on an intermittent problem, especially if you don't have a scope to hand.

nelso419

Think this is the issue?

mrgreenjeans

yes.
It shows the effects of water corrosion and appears to have now made a common electrical path to at least several points.

toasted

nelso419

Cleanable?

mrgreenjeans

and you may also wish to find new 'certified Porsche' mechanics.

Yes, join your local PCA region, find the guys who own and/or race 944s and the ones who have owned their cars the longest and get referrals, as many of the Porsche wrenches currently repairing @ the stealership have no training, knowledge, or even maybe ever seen a 944 before.

Think this is bad ? Try getting help from one on a 914 or 356 ........

mrgreenjeans

wouldn't waste my time. See where the corrosion has gone under the sealed surface meant to keep an electrical path from shorting ? Its unreliable at best and may certainly fritz out something else. Get a new one and make sure the water leak that ruined it is repaired as well.

nelso419

Thanks everyone.

nelso419

Any advice on which one to get?

http://944online.com/index.php/944-2...dme-relay.html

Tom M'Guinn

Agreed. An easy way to tell if it's dead is to check the boot gauge with the ignition on and motor not running. If the relay isn't supplying power to the DME/KLR, the boost gauge will sit dead. If the relay is working, the gauge will read "1". I think of it as a two part test -- is boost gauge at 1, and do you get tach bounce? The combo of those two go a long way toward diagnosing a problem. I actually though the "certified" mechanic tested that, but re-reading the first post doesn't actually mention it, so it makes you wonder where that certificate came from. Hard to say from a picture whether it works, but if it's original to the car I'd replace it even if it isn't the problem (and/or carry a spare).

Tom M'Guinn

You might check out pelican parts for more options. If you car is currently not starting, I'd try jumpering it and/or checking the boost gauge. I'd still get a new relay, but this way you'll know whether to keep working on the car or just sit back and wait for the relay.

nelso419

I totally forgot to mention, the car is running. I was driving it into the parking garage at my work after picking it up from the mechanic and it died on me. I pushed it into a parking spot, pulled the relay out and put it back in and it started. I just scraped off all of the rust at my desk and I'm going to go try it again.