Vacuum EZL vs 4 connector style EZL - PeachParts Mercedes-Benz Forum

Mighty190 · #1 04-17-2019, 06:27 PM

What is the difference between the two styles of m103 EZL other than one being vacuum controlled? We have a 1989 190E that has the 4 connector kind on it but one of them doesn't go anywhere. That leads me to believe that were not getting the right spark advance.

Duke2.6 · #2 04-18-2019, 12:41 PM

I'm not aware that the '89 configuration is different than my '88 190E 2.6, but mine has a vacuum line from the manifold to the EZL. Most of it is that 3 mm white nylon tubing, but there are short, molded rubber hoses at both ends to connect the nylon tube to the nipples at both the inlet manifold and EZL.

The EZL has a sensor that converts manifold vacuum to additional spark advance (basically an electronic version of the old mechanical vacuum advance "can"), but it's disabled by a signal from the throttle position switch when the throttle is at the idle position. At idle, timing is fixed by the EZL at 9 deg. BTC and is not adjustable.

Duke

Mighty190 · #3 04-18-2019, 05:23 PM

How many connectors does yours have on it? We have wires for the CPS and then the other two large ones further down on the EZL and both do have the vacuum port I was mistaken. What I'm referring to is this difference shown with these images I found online https://imgur.com/a/0rWHWCH

Edit Looks like that extra connector is for a knock sensor that we do not have https://www.benzworld.org/forums/w126-s-se-sec-sel-sd/1511396-electrical-wiring-diagram-ezl-8-pin.html

Duke2.6 · #4 04-19-2019, 10:51 AM

The image wouldn't download. The EZL on my '88 has two large round multi-pin connectors at the bottom and a small round connector near the top next to the nipple for the manifold vacuum signal line that I believe is for the crank position sensor, and no additional connectors for knock sensors.

It appears to conform to the block diagram in the Benzworld image, but not to the pin diagram image, which has provisions for knock sensor inputs.

The part number is 006 545 75 32

Duke

Mighty190 · #5 04-19-2019, 04:49 PM

Right I think its just that the extra connector is for a knock sensor we don't have.

duxthe1 · #6 04-19-2019, 10:07 PM

Quote:

Originally Posted by Mighty190

Right I think its just that the extra connector is for a knock sensor we don't have.

In addition to the knock sensors, there is also a bi-directional data connection between the EZL and the CIS. This was the first time Mercedes shared data between modules. Its also a big part of why you can't interchange them with the earlier version.

Dr. Sternschnuppe · #7 04-20-2019, 02:00 PM

Quote:

Originally Posted by Mighty190

Right I think its just that the extra connector is for a knock sensor we don't have.

The M103 engine on 201 chassis doesn't have knock sensors...

Mighty190 · #8 04-23-2019, 09:09 PM

We ran it at a track day this weekend. It ran well with the ezl that uses a knock sensor but had a huge jump in power at round 4k with the one that seems like it belongs in the car. So that was interesting.

In regards to electronic fuel and ignition control that would be nice. I don't have time or money for that project. If we focused on making everything perfect the car would never run .

Duke2.6 · #9 04-24-2019, 12:02 PM

Quote:

Originally Posted by Mighty190

We ran it at a track day this weekend. It ran well with the ezl that uses a knock sensor but had a huge jump in power at round 4k with the one that seems like it belongs in the car. So that was interesting.

In regards to electronic fuel and ignition control that would be nice. I don't have time or money for that project. If we focused on making everything perfect the car would never run .

I don't know how your engine varies from the OE configuration, but you can get a more aggressive spark advance map by removing the R16/1 resistor that is in a pigtail tied to the plastic panel inboard of the battery.

About ten years ago I took the spark advance map (less vacuum advance) for the OE 750 ohm resistor, no resistor, and the connector shorted. The most aggressive map is with no resistor, but I think this config. and the OE resistor both yield 32 degrees max advance at 3200 revs, but with no resistor there's much more advance down low, which provides noticeably more torque/power down low and allows me to use 5th gear down to as little as 30 MPH (about 1200 revs) vs. 45 MPH with the OE resistor.

Either way the engine has a strong pull from 5000 to the rev limiter, but with no resistor the power curve is more linear from off-idle to the rev limiter.

I short the resistor for emission testing, which significantly slows the rate of advance with increasing revs because it lowers emissions (HC is on the ragged edge with the OE resistor), but there is little power below 2000 and virtually no power below 1500.

You can search for threads started by me to see the data.

Duke

97 SL320 · #10 04-19-2019, 08:37 PM

I'd probably dump the $$$$ EZL and use a electronic advance ignition from someone like MSD. This way you have full control over the spark curve.

97 SL320 · #11 04-19-2019, 10:17 PM

I wonder of this is actual data ( Like over CAN ) or just an analog signal or frequency for engine load.

duxthe1 · #12 04-20-2019, 12:08 AM

I've heard is described as the "earliest version of CAN" and afaik it is serial data.

JKMorahan · #13 04-24-2019, 05:37 AM

KE3 doesn't really need any piggy back fuel control. Literally 2 of them identical to any 103 setup is bolted in a twin setup on a Ferrari Testarossa. Stock out of the box they are rated for as much as 70% fuel requirement increase without any modification. The Lambda loop its fuel control module operates has 5-6 bar of fuel pressure to work with and has no problem at all maintaining stoichometric with vastly increased fuel delivery requirements without any modifications at all. Note also that WOT switch on the linkage disables the lambda loop for full throttle enrichment so that's not an issue either.

The KE3 problem is spark mapping, since it doesn't have a knock sensor it is like an early electronic ignition setup, little better than a points ignition system in that it is designed to pre-emptively prevent engine knock rather than dynamically prevent it like modern EFI. So you never get quite as good a spark advance as you could, due to the error margin required with predictive systems and it retards when it may not need to, finally an end user lockout means you can't remap it for custom camshaft profiles or forced induction conversions so you never really get the most out of a dramatically modified engine without a spark ECU piggy back you can map.

That is, unless like me you got super lucky and happened upon a genuine AMG 3.2 ignition module in Amsterdam and installed that to recurve your spark for a hotter camshaft. Still not as good as EFI but much cheaper even at the collector's price of an original M103 AMG part.

Duke2.6 · #14 04-25-2019, 12:43 PM

I don't think the 3.0 manifold will fit under the 190 hood, and I also think it has slightly smaller ports, which will limit top end power... not sure about the exhaust manifold ports.

...suggest you use a dial back timing light to map out the WOT spark advance curve with the vacuum line to the EZL disconnected and plugged. The 4000 rev torque surge may be caused by a lazy spark advance curve below that speed.

Duke

Mighty190 · #15 04-25-2019, 03:30 PM

I'm certain the issue was in the ignition curve given it's tied to the EZL.

As for ports and what fits the 2.6 and 3.0 ports measured the same. We had a 3.0 manifold on a 3.0 in this car at one point and it fit but the egr blockoff was ugly and extra points of failure.

The air cleaner has never fit right on this car. The base is bent and that's an item on the todo list.