Author Topic: 94' 318i No spark (Read 4395 times)

theaddler · « **on:** January 19, 2010, 05:29:43 PM »

So as soon as the rain tapers off a little I will confirm no spark, but my car cranks great, has fuel, but will not start. When it died, it didn't chug and die, it was just an immediate 'not running' condition. I was told to check for spark at the plugs, tehn, if no spark, move back to the ignition box and check for power going in. Any other thoughts of where/what to check? Thanks!

bimmerd00d · « **Reply #1 on:** January 19, 2010, 05:52:01 PM »

I'm new to the boards here, so my M42 based knowledge is limited....for now. I've seen a cam and/or crank position sensor do this on the 6/8cyls quite often. My E39 540i did the same thing a while back. Plenty of fuel, no spark one day.

DesktopDave · « **Reply #2 on:** January 19, 2010, 05:58:08 PM »

Check your DME compartment for flooding. The drain on the firewall clogs with leaves, then the next car wash or heavy rain shorts out the DME. After you dry it out the car might work 100%.

If not...well, I've heard of some people opening the DME case & gently heating it on low in the oven to bake it dry for a few hours (under 200degF, more heat will damage it).

theaddler · « **Reply #3 on:** January 19, 2010, 09:53:38 PM »

Hmmmm DME compartment? You mean the actual computer? (I'm an old car guy...)

Would I look for something else in Haynes manual?
Thanks

DesktopDave · « **Reply #4 on:** January 19, 2010, 10:08:14 PM »

Yep, you got it. The whole world calls it an ECU, except Bosch...they named them Digital Motor Electronics, or DME for short.

The wet DME is common on e36s built before 6/94. Here's a few write-ups:
Click me
Me too
And me.

The ECU sits in the plenum on the passenger side. You can get to it from the engine compartment, just remove that plate on the passenger side firewall (where the battery would be if it was a 'vert).

One more thing...if you have to replace the DME/ECU with a used/new/refurb unit, it'll have to be "aligned" to the car/keys/BMW magic kingdom by a BMW service department (or a BMW hacker). There is a system called EWS to protect the DME (from being modified by mere mortals like us). BMW and Bosch get their panties all in a wad when you edit their systems or improve the breed. Seems like they've forgotten the fact that we actually work on the cars they build. So they installed several troublesome systems to prevent that (and make the dealers a little money).

I would highly suggest if you can't fix the DME, get it chipped by someone to eliminate that EWS garbage. Maybe send BMW NA a letter too.

dvmotorsports · « **Reply #5 on:** January 20, 2010, 12:18:26 PM »

had this exact problem on my 92 318is. went through a car wash and that was all she wrote. about 24 hours later, all was well. DME got wet.