300CE No Spark (Help)! 1990 DOHC 6cyl - PeachParts Mercedes-Benz Forum

yellit · #1 12-12-2010, 03:55 PM

Died in carport and now no start....
New coil, New CPS, New Cam Sensor, 12 volts to coil from EZL, distributor,wires and rotor 3 months old, good battery voltage, Starter turns engine fine, no spark output from coil and no 12 volt switching from EZL to coil ....good pulses from sensors to EZL viewed with O-scope..
Does anyone have any ideas.....?....or is this the dreaded EZL death ?

mbdoc · #2 12-13-2010, 08:18 AM

IF you have plenty of power & ground to the EZL & the crank sensor generates at least 0.5Vac while cranking...the EZL is the most likely problem.

Good luck

yellit · #3 12-13-2010, 01:13 PM

Thanks for the reply MB Doc....!
Was wondering what the minimum required signals are needed for the EZL to generate the switching pulse on the coil primary winding...?
EZL has about 8 inputs such as cps, cam, temp, vacuum and such...
I know the Crank position and cam position are needed for spark but not sure if it will fire if other signals missing or weak....Thanks again for your help....!

yellit · #4 12-14-2010, 12:59 PM

Also trying to find good tutorial on pulling codes (types, tools,connectors, engine on or off) ?? ....not having much luck with info access....

jhodg5ck · #5 12-14-2010, 10:44 PM

EZL is super common on the CISE M104's. We have had two such cars in the last year, both had fragged EZL's. Went through the same diagnostics.. When there's nothing else left... When you Do get a new one be sure to renew the thermal paste!!

Jonathan

yellit · #6 12-15-2010, 05:41 AM

Thanks for the replies....Im just trying to find a way to read any stored codes to see what is going on since there has been a lot of work done on this vehicle ...seems to be two or more devices needed to read codes....

samiam44 · #7 12-15-2010, 03:11 PM

you can build one or buy one on ebay...

Cannot do anything but that's what most of us use.

yellit · #8 12-15-2010, 11:31 PM

Yep...got one but have read that it can only read codes if engine is running.....
That is the problem....The engine has no spark and cannot run yet...I have the module apart to find the output stage if possible...you can de-RTV these with (rubber renew) liquid used on tape machine capstan rollers....

yellit · #9 12-16-2010, 02:48 PM

Does anyone know of a list of Ignition modules that will work on this 1990 300CE M104..??
I see members speaking of some interchangeability between modules....where can I get that info if available.....Thanks.....this thing is killing me.....Help.....

jhodg5ck · #10 12-16-2010, 04:04 PM

Only cars w/ the M104's @ CIS, ie the early W124 coupes and the early R129 300's.

IIRC, 90-92 on the coupes, and 90-93 on the SL's.

Jonathan

mbdoc · #11 12-20-2010, 08:21 AM

Other than a reman unit from a MB dealer, a used one is the best bet.

yellit · #12 12-22-2010, 01:41 PM

Well this has now reached a point of sadness & desperation......depression has set in....

Does anyone have a pinout of an EZL # 016-545-0432...?????....
1990 300CE M104
This is the 8 pin per connector style....
Mainly looking for pins 2 and 5 on connectors XA and XB......HELP?!
Or any of the 8 pin per connector modules by chance....??

Ferdman · #13 12-23-2010, 03:18 AM

yellit, I know from personal experience that the EZL for a 1991 300CE cannot be reconditioned due to epoxy covering the internal components. Contact Beckmann Technologies if you want to confirm that fact.

After a futile search for a used EZL I ended up buying a new one from our local MB dealer for around $1,800 (wholesale price). If you go that route advise the Parts Department to search under EZL's for a 1990 300SL because their system will say the 300CE EZL is backordered (at least that was the case when I searched for one about 5 years ago).

Routine maintenance of the ignition system (distributor cap, distributor rotor, spark plugs and ignition wires) will prevent EZL failure. I know that's not what you wanted to hear, but those are the facts I learned from the same situation as yours.

yellit · #14 12-23-2010, 03:33 AM

Thanks for the reply.....This module is certainly of the devil.....

I have seen several posts about the inside epoxy thing, but what is in this one is just a very clear layer of very soft, almost flowable silicone gel or such....
It can be removed easily with q tips although it does want to pull back a bit.....
It could even be put back in after removal but it loses some of its transparency.....
Best consistency that comes to mind is that flowable silicon gel that you can get at parts stores for windshield leaks.......I am familiar with the epoxy bound circuits in devices but this is a different animal.....maybe its just in the Seimans units and not the Bosch.....Thanks again....