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You should return the second DME and see about trying another.
Headlight switch or dimmer might have a short. Maybe your fuse failed to blow
I hope I can still return it I need to doublecheck the warranty. I wish I had a running car to test both of them on. And even if something was wrong with the car itself, how could one DME run it but another DME won’t? Tf is going on with this car?
It's quite the challenge, for sure, esp given you've replaced the main wiring harness (iirc)
Lol yup that’s brand spanking new from the factory. Shout out to Gene at Porsche Chandler for helping me get everything I’ve needed lol.
I sent the refurbished DME back to the company I bought it from where they’ll do extensive testing on it to verify 100% it’s operating correctly. Unfortunately without a donor DME or a spare running car I’ve hit a wall with testing. I don’t know what else to look at.
Well I’ve got news regarding the remanufactured DME I purchased. I had it sent back and tested. Unfortunately the unit tested good.
So the DME that starts my car, and then kills it right away is testing good.
Wiring harness to all of the sensors and back to the DME is brand new
all the sensors are good
I’ve got spark, fuel, air, compression
and im still sitting here with my finger up my a**
i hate to say it but I think maybe it’s time to drop more money and get it back to the dealer. Even though after a full 3 hours of diagnosing and testing they couldn’t give me an answer.
Keep in mind with the other DME the car started and ran. Guess that DME is toast? Or are they both trying to correct for the same issue in different ways.
I can see that you have been really thorough and meticulous which is really impressive ........... I hate to have to say it but.........
You've missed something ........................somewhere something hasn't been connected correctly because the DME relay bypass will not to work.
if a 3x wire DME relay bypass doesn't work................ then the DME relay will also NOT WORK so the car will never start That is an indisputable fact .......
Until you sort this issue you are wasting your time looking anywhere else
The easiest way to tackle this is to break it down into separate sections .
I would start with the DME relay base in the fuse relay box. Remove the DME relay base connector and check all the wires are correctly connected .
I can see that you have been really thorough and meticulous which is really impressive ........... I hate to have to say it but.........
You've missed something ........................somewhere something hasn't been connected correctly because the DME relay bypass will not to work.
if a 3x wire DME relay bypass doesn't work................ then the DME relay will also NOT WORK so the car will never start That is an indisputable fact .......
Until you sort this issue you are wasting your time looking anywhere else
The easiest way to tackle this is to break it down into separate sections .
I would start with the DME relay base in the fuse relay box. Remove the DME relay base connector and check all the wires are correctly connected .
Okay peanut. I took your advice and had a look as best as I could down there. U fortunately I couldn’t get any pictures because it’s just too cramped and too dimly lit to get a good photo. I disconnected the battery and slid out the block as far as I could. Disconnected the FP relay to get my hand back there and felt each wire. Each wire felt good like it was solidly conected and smooth so no corrosion.
Obviously this doesn’t explain the issue you’re describing with the bypass not starting the car and the relay starting it. But at least I can confirm the connections at the relay block are good.
I reconected the battery and took one more slow look into the engine bay. I reread everything I could find about “car starts then dies right away” pulled up a bunch of threads on pelican. One person mentioned to unplug the DME coolant temp sensor[ yes the one you made sure I triple tested and sent in the photo, fuel injector type plug into the block]
So I unplugged it and gave it a go. Viola. The car starts AND runs with the new DME. Only for a short period of time, about 30 seconds or so, but doesn’t start then immediately die like it does with that sensor connected. Something else fishy. Remember how I was asking about that oil pressure light, and why it doesn’t illuminate when the car stalled? Well with the coolant temperature sensor disconneceted, when the car finally stalls, the oil pressure light comes on as it should. I knew I wasn’t imagining that light illuminating after a stall. I tested the sensor it’s brand new and it’s working.. The wiring harness that connects that sensor to the DME is also brand new so it’s not like there’s any shorts or corrosion to cause an issue. With the connection at the fuse block good and tight, and this new way of getting the car to start and run, where else to I need to look? It seems that the heart of this issue, the fuel to air stoichiometric ratio is off and something is throwing it off. But like you said I must be over looking something so obvious it should be smacking me in the face.
The oil light issue reminds me of grounding problems: I know your harness is new, but do re-check all the grounds and where they connect to (ie, connection points are clean).
I forget what you did with th AFM, but that seems like an item to review. Jiggling the key doesn't change anything, does it?
The oil light issue reminds me of grounding problems: I know your harness is new, but do re-check all the grounds and where they connect to (ie, connection points are clean).
I forget what you did with th AFM, but that seems like an item to review. Jiggling the key doesn't change anything, does it?
The AFM was replaced with a known good one from a running ‘84. I’ll double check every ground point and try to hit and the surface it connects to with a wire brush or something.
juggling the key doesn’t have any affect.
Ironically I found a thread where someone had the same exact issue, their car wouldn’t idle unless the coolant temp sensor was unplugged. They replaced it. Didn’t change anything. They put a new DME in it and the car was fixed 😂😂😂😂. Ugh this car is gonna give me a brain anurism lol.
well at least you are honest about mistakes which is commendable.
Now how many times did you test the engine temperature sensor lol?????
What colour is the plastic connector of your engine temperature sensor ?? it should be blue if it is correct. Otherwise you could have fitted a engine coolant sensor that runs fans which is an entirely differant sensor
Do you see what I have been banging on about now Jacob. ? If you just assume something is good because it is new then that is very shoddy troubleshooting.
I asked you to check the DME relay base which means using a multimeter and tracing the origin of every single wire that fits into that connector against the electrical schematic not just pull on the wires lol
If this problem was solely due to a missing or poor ground then the engine wouldn't start and run at all .
You need to concentrate on what you know is faulty .........which is the connections to the dme relay base. Somewhere something is either connected to or disconnected from the wires associated with the DME relay base because the car doesn't fire up with a 3x wire bypass.
You really should do a bit of reading about how the dme relay functions
well at least you are honest about mistakes which is commendable.
Now how many times did you test the engine temperature sensor lol?????
What colour is the plastic connector of your engine temperature sensor ?? it should be blue if it is correct. Otherwise you could have fitted a engine coolant sensor that runs fans which is an entirely differant sensor
Do you see what I have been banging on about now Jacob. ? If you just assume something is good because it is new then that is very shoddy troubleshooting.
I asked you to check the DME relay base which means using a multimeter and tracing the origin of every single wire that fits into that connector against the electrical schematic not just pull on the wires lol
Trust me at this point I’d rather have a wounded ego and a running car lol.
well it looks like the correct sensor but looks ain't everything.
The only way to be certain is to suspend the tip of the sensor into a glass of hot water with a thermometer and stick a resistance meter on the 2x terminals . Add a little cold water or boiling water and see what temperature the sensor switch operates at . its a fiddly messy test but it gives you a definitive result
Continue testing as peanut suggests, esp. the connections at the relay / fuse box. I suspect this is going to end up being either a "good" part proven bad after all (ex. DME) or some completely unpredictable issue such as loose or bad connection at the DME plug.
Seems the DMEs behave different each time you unplug & plug them
02-26-2019, 10:25 PM
