IF DME is mounted (grounded) car wont start

[grave77]

back to 5 series board, but with a problem, my 535 been parking for a long time, and I crashed my 850i so I need to use my 535 again, but it wouldn't start at all, unless I remove the DME and dangle it then it would start.

for reference, when the car doesn't start the transmission mode on the dash shows (E P) when I crank the engine the E turns to S to be (S P).

stomb test is not an option in my car so I cant read anything.

any idea what's going on?

by the way when the DME is not mounted and the car starts it runs 100% normal.

I have 2 DMEs I tried both and the both behave the same.


Thanks

[BigKriss]

ouch, do you have any pics of the accident?

back to 5 series board, but with a problem, my 535 been parking for a long time, and I crashed my 850i so I need to use my 535 again, but it wouldn't start at all, unless I remove the DME and dangle it then it would start.

for reference, when the car doesn't start the transmission mode on the dash shows (E P) when I crank the engine the E turns to S to be (S P).

stomb test is not an option in my car so I cant read anything.

any idea what's going on?

by the way when the DME is not mounted and the car starts it runs 100% normal.

I have 2 DMEs I tried both and the both behave the same.


Thanks

[632 Regal]

you must have a frayed wire thats shorting to ground somewhere. sorry not more informative.

[Karl]

you must have a frayed wire thats shorting to ground somewhere. sorry not more informative.

I'm with regal on this--a frayed wire either inside the connector to the DME or close to it that grounds when you push the DME into place. That's not easy to find.

[632 Regal]

it isnt easy but Barry is an electrical guru. An ohm meter should tell you just about every wire is a ground...the attempt to find the one that isnt suppost to ground might be the challange. Where's Javiar anywho? Follow the wires from the DME, hopefully its shorting in the DME box somewhere.

I'm with regal on this--a frayed wire either inside the connector to the DME or close to it that grounds when you push the DME into place. That's not easy to find.

[grave77]

well I would take a look for sure, the shitty problem is that the battery got a very little charge to crank the engine.

I guess it's more than a fried wire, just when I crank the engine tranny mode changes to S and there is no spark from the coil, and also no gas smell, so the whole DME is stopping.

I need to know what would inhibit the DME then it will be easier to start tracking wires.

[grave77]

no dude ... I didn't care about taking pics cuz I was so frustrated, you can imagine an E31 with a totally destroyed front, the whole fiber nose is like a biscuit crumbs the engine hood is a little bent from the left.

luckily I found a front nose from the scrap-yard but I need the 2 flashers and the 2 high-beam lights.

[Ferret]

well I would take a look for sure, the shitty problem is that the battery got a very little charge to crank the engine.

I guess it's more than a fried wire, just when I crank the engine tranny mode changes to S and there is no spark from the coil, and also no gas smell, so the whole DME is stopping.

I need to know what would inhibit the DME then it will be easier to start tracking wires.

Are you sure that you're not just disturbing a knackered DME relay when you pull the DME out?

[grave77]

I'm not sure of the symptoms of the relay but I wrapped the DME with news paper and slotted it in da box between the screws so it wont get grounded, car runs fine now ... all wires are intact no stripped on burnt wires. I'm afraid that the tranny control is playing games since it's bypassed and I get the tranny failure message, but I guess that would be in the V12 engine only. I'll keep observing to see more of this odd problem.