What is the function of the EZL, 1993 300E, 2.8 M104 - PeachParts Mercedes-Benz Forum

latief · #1 07-16-2010, 10:40 PM

Simple Question: What is the function of the EZL? I am not familiar with the 103 engine, and I am trying to help a friend fix her car..the Mercedes shop says the hesitation in the engine is due to a worn out EZL ...

Also, anyone know what the part number for the EZL would be? 1991 300e is the car

Thanks..

tjts1 · #2 07-16-2010, 11:35 PM

EZL doesn't really wear out. It either works or it doesn't. EZL is the spark timing control computer.

Gilly · #3 07-16-2010, 11:44 PM

Part number is on the current EZL.
Maybe you should just tell us what the problem with the car is and what you've all broken so far.....

latief · #4 07-17-2010, 01:01 AM

Car died.....would start and die once you hit gas....

towed it to a Mercedes shop. worked on it for two weeks ....

they Changed the fuel system coil...it was dead....car started but was still not right...

they changed sparks and wires and distributor cap....still car had something wrong with power delivery.....you hit the gas and it was flat..picks up power eventually...

they discovered a dead computer (was running on the default map, no adjustments)....changed that along with the O2 sensor...car became much better, but still had a flat spot......

they discovered the timing was off. they dug into the engine and fixed timing.....

car became much better, but still has a slight flat spot in acceleration...

during testing, a bolt came off the fly wheel and destroyed a couple of things in there....they fixed it (half and half on money)....

the tech borrowed an ezl from another car....he says the power was restored to normal level...so now i have to find an ezl since they cannot find one....

$1700 bill...

car worked for a month and died again....towed to the shop and found severe gunk in the fuel system .....cleaned it and changed filter $270 bill

I broke nothing, and touched nothing until this point.....

this is a dealer maintained car with service records.......dealer is an idiot....and i am not happy that all this has been done with the original problem still in there

Fun isn't it ?!!

Ivanerrol · #5 07-17-2010, 04:42 AM

Let your fingers do the walking.

Type in "Mercedes Ignition Unit" at the great auction site and find out what you can. Make sure your have your part number to compare.

Unfortunately odd bod M104 EZL's are generally $$$$.

Took us a couple of months to find a suitable EZL for a early version M104 in a 300CE 24v

400Eric · #6 07-17-2010, 06:45 AM

This is just a regular 91 300E. I don't know about your neck of the woods but out here these cars are showing up in the U-Pull-It yards in big numbers now. There's no reason to pay very much and there is no reason to deal with the operators on KnappyBay or those thieves at the stealership.
Regards, Eric

Cal Learner · #7 07-17-2010, 07:41 AM

Wouldn't hooking the car up to the SDS (or whatever it's called these days) pintpoint the issue fairly quickly, and be a lot less expensive than re-building the motor one part at a time? Tell me that the shop that did all the work wasn't Steve B's place!

latief · #8 07-17-2010, 10:00 AM

Quote:

Originally Posted by Cal Learner

Wouldn't hooking the car up to the SDS (or whatever it's called these days) pintpoint the issue fairly quickly, and be a lot less expensive than re-building the motor one part at a time? Tell me that the shop that did all the work wasn't Steve B's place!

They had it hooked up to their diagnostic devices (if that was what you were referring to)....the car had a dead computer, and that gave the tech a hard time i think....

yes for the shop ...

latief · #9 07-17-2010, 10:06 AM

Quote:

Originally Posted by 400Eric

This is just a regular 91 300E. I don't know about your neck of the woods but out here these cars are showing up in the U-Pull-It yards in big numbers now. There's no reason to pay very much and there is no reason to deal with the operators on KnappyBay or those thieves at the stealership.
Regards, Eric

Any idea if the EZL is a an item that wears out gradually causing performance degradation? or is it just either working or broken? I will be looking for a used one if anyone confirms this point....i can find them online for $40ish.....

I think it is a couple of thousands at the dealership

thanks for all the input guys.....

deanyel · #10 07-17-2010, 11:24 AM

Any frail electrical connection can be impacted by temperature, humidity, vibration, etc. The EPC says either 008 545 96 32 or 009 545 80 32 will work. Only 96 32 is still available from dealer, $1,000 list, $690 at parts.com.

Ferdman · #11 07-17-2010, 12:13 PM

latief, not sure about the internals of a 103 EZL, but those of a 104 EZL are epoxied which prevents the remanufacturers from identifying the internal components for potential reconditioning purposes. A few years ago used 103 EZL's were readily available from salvage yards, and cost around $40.

From my experience with a failed 104 EZL I would say they are either good or bad ... no in between stage. In your position I would recommend buying a used EZL once you verify that is indeed the problem. A local MB dealer diagnosed the bad 104 EZL quickly. In my case the engine suddenly would not start after eating lunch at a restaurant.

latief · #12 07-17-2010, 01:35 PM

I am just going to get a used one off ebay/ junkyard and see...

the tech said the problem was fixed once he used the loner part....

Gilly · #13 07-17-2010, 11:13 PM

They either work or don't usually. BUT what can happen is they will cut out on you, so might work for awhile, then make the car stall. Now, when they act this way, they will usually stop working under high underhood temps, so this time of year is when you can see the problem.

Gilly

400Eric · #14 07-18-2010, 06:51 AM

Quote:

Originally Posted by latief

Any idea if the EZL is a an item that wears out gradually causing performance degradation? or is it just either working or broken? I will be looking for a used one if anyone confirms this point....i can find them online for $40ish.....

I know this is often the case with the CIS-E ECUs and I've also seen this same phenomenon with coils but I'm not sure about the EZLs. Haven't had or even seen a bad one yet! I don't think they go bad very often.

One thing I am sure about though is that you can often times fix a "bad" part by just unplugging and then replugging the connections on that part. Actually, the same is true for just about every electrical thing on a 20 year old car. I firmly believe that half the time, when a "new" part "fixes" a problem, it was really just the disconnecting and then reconnecting of the plugs thus re-establishing the electrical connections that was really the cure but the "new" part gets the credit.

And if you really do need another one, go to the U-Pull-Its, save some money, and actually see and choose which donor car you want to get your parts from. More peace of mind that way. Stay away from the full service yards.
Regards, Eric

cth350 · #15 07-19-2010, 12:25 AM

The EZL needs a good thermal contact with the body. The factory part has a layer of toxic white goo to provide it.

For longer life on your used unit be sure to replace the goo. I don't think it can be purchased, as I never tried. Radio Shack sells a suitable dialetric conductive paste.

-CTH
PS. and for your longevity, be sure to wash well after getting that crud all over your hands.

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