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so, this is the unit i bought my car with and ran it for six years. no issues so far. seems to have a more aggressive curve. car seems to be more alive with it.
did not know about that unit. never removed it until rebuild. then i was surprised to find it - not the 965 type.
today i would not run my car up to limit on geman autobahn with this. speedo shows 310 km/h then. in the past i did.
as a backup this should be fine - i kept it for that reason.
This part has also been applied to the MB 300E/SE engines, series W124/126.
Unfortunately, there are no part usage or product identification lists to be found on the web for the ignition control units, as is the case with the K-Jetronic components. This could be helpful to determine i.e. the differences in max ignition advance.
I have now written to Bosch Classic about documentation on the EZ, but there is little hope that something will come of it.
Here is a C2 Turbo EZ-69 ignition map from a 1991.
I leached this off the web when I converted to Electromotive 2 plug crank fire ignition.
The map is accurate, I was able to check with a degree wheel/tape and timing light on a working 1991 C2 turbo.
IF, you instal a Mercedes or other EZ-69 you can check the same way and compare the ignition map to the Porsche EZ-69 map
Looking at an old thread, this interesting morsel - I was running up the boost on a fast bit of freeway when it failed, so this could be what happened (torn diaphragm), but seems off to me that the thing would cut off spark signaling altogether rather than just stop including the boost pressure in whatever its calculations are.
Also a lot of talk about how they get hot and the cycling hot cold can help fry electronics in the box - what about adding some ventilation to the case? Or maybe a fan? Reminds me of a mod I made on my Mac 2 in 1990 - overclocking it to 50mhz required a heat sink and a fan...
A couple of years ago I removed my EZ69 after buying a spare and put in my closet with all my other valuable spares. I have running the spare with fresh paste and a ground strap from the chassis to the aluminum mounting plate since. No issues! After speaking with a shop in Germany, the guy said running too high of boost with cause issues with EZ69, He said it blows the diaphragm in the EZ69, I was confused ??? Does the EZ69 see boost vacuum or pressure. Not sure how that works. The other shop the rebuilds these units for MB said to common issues they see, lack of thermal paste and they burn up. That's what I heard. He also mentioned that he would ship me freshly rebuilt Bosch 0227400538 MB unit to try on my car for free after I explained Peterpullin's findings
wicks the diaphraghm is the only part that can be replaced without cutting the unit to pieces. i know someone in germany did this in the past. the part is not available from bosch - so he put in something similar.
i kept the mb unit as backup in my glove box for the thing that happened to you: quick help for dead ez on the road.
Very interesting question below. I shall ask them.
Fritz > my EZ is on it's way to you now, will email you tracking info when avail.
Peter > thanks for posting that, I will grab one hopefully soon that I can use to get the car home and keep as a spare for road trips...
THANKS ALL EXCELLENT PEOPLE FOR YOUR HELP!
Wicks,
Please let us know how ECU.DE responds to you, and if they are able to start with the MBZ unit (Bosch P/N: 0227400538) and convert it for a 3.3 or 3.6 965. Thank you.
TIA
I was confused ??? Does the EZ69 see boost vacuum or pressure. Not sure how that works.
Both of that. On an N/A engine there is only vacuum, on a turbo there is vacuum when naturally aspirated (no boost) and pressure when the turbo kicks in.
Among other things for this reason I am also somewhat reserved when it comes to using the MB ignition control units, which only know vacuum.
The manifold pressure sensor in the EZ69 detects the load condition of the engine. From a pressure of 1250 mbar (= boost pressure approx. 0.3 bar) at an ignition angle is output which corresponds to the full load map. As far as I can gather from the documentation, this is a simple yes/no detection, i.e. there is no continuous adjustment depending on the boost pressure, but the pressure sensor switches back and forth between full load and normal map.
With the MB devices there will be no full load map switched on because there is no pressure any time in the intake manifold detected.
05-12-2023, 04:30 PM
