Unfortunately pin 2 has connection to all the other pins, except for TD. ...
... Once again HD, thanks for all the help. This is a path I would have never went down without your guidance. ...
You‘re welcome! …
... If you don't mind, can you explain the purpose of the EZL? My understanding is it adjusts the variable timing but I'm sure there's more to it than that!
In the non-German speaking world the abbreviation “EZL“ is usually incorrectly used for the ECU that controls the ignition. “EZL“ is the abbreviation for “E
lektronische Zündanlage mit Z
inienverstellung“ (electronic ignition system with variable ignition timing). That‘s the name for the entire ignition system. In order not to cause unnecessary confusion here at Benzworld I use the abbreviation “EZL“ - with an odd feeling
- for the system‘s control unit too.
The EZL gets a number of electrical input signals & input about the intake vacuum level, based on which it recognizes the engine‘s operating condition and determines the ignition timing. One of the input signals the EZL not only uses for the ignition timing. The one from the CPS (Crankshaft Position Sensor) is converted into the “TD signal“ which represents the engine‘s speed and is also sent as input signal to other components (FPR / MAS, CIS-ECU, idle control unit).
The input signal that arrives at pin 2 of your EZL‘s control unit is the TPS‘s “throttle closed“ signal. … In other words, the wire that carries the TPS‘s “throttle closed“ signal to the CIS-ECU is always connected to the wire that carries the same signal to the EZL‘s control unit, no matter whether the TPS connector is connected or not. … And that‘s the “other path“
I had (mainly) in mind and repeatedly mentioned up from post 108 in order to trigger an “aha moment“ among the readers of this thread. …
BTW … this is a perfect example why I always suggest to first check sensor signals at the connector of the component that processes them
(ECU, FPR, MAS, EZL, idle control unit, …), not at the senor itself !
… People who would have checked the TPS‘s “throttle closed“ signal only at the TPS connector, where it worked perfectly, would probably have thought that everything is okay with it and never have found out about this problem … and possibly thrown many more parts at it. …