1994 MB E420 issues idle/surging/stalling LONG

[DRICHFL]

Hello to all forum members, I have been reading the information posted on this site for over a year. This site is one of the best source of information for all MB lovers. I finally became a registered member in hope that someone can benefit from what I have experience with my 94 MB E420.

I would like to thank greats guys that I personally emailed for help; such as, Jimf, Anthony-Italianbenz, Matt D-Matrix, Andy-eandytemp, Fred-Zerox, Gerald-Zerox, and Tom P-tomp. I would also like to thank the countless forums posted on this site that contribute to my success in repairing my E420.

In the fall of 2004 my E420 let me down on the highway and I had to be towed home. Before the car failed the cruise control stop working and the Check Engine Light was on. The car engine also surged up and down and would not hold an idle then it died. After the tow home, I use the push botton LED and got the code that point to bad Electronic Throttle Actuator/ EA. I new it was not a wire harness problem because the dealer replace the harness two years ago. I automatically purchase a new ETA from the $tealership.

After installing the new ETA and hose that runs to the valve cover, I started the engine. The engine started instantly, only to shutoff within a second and a half. It seem to be hunting for a idle. I attempt to perform the relearning process by turning the ignition key to the secound position and wait for two minutes then turn ignition key off and remain off for a minute. I did this process of relearning several times so that the ETA would learn full throttle.
Still after restarting the engine the same result with no success. I later built Jimf scanner and scanned each module. I got all types of crazy codes for each module. I cleared them all and made several attempt to restart the engine. I rescanned each module again an got some strange stuff so I began replacing parts.

Safety neutral switch replace
Coolant temp sensor replace
GM Base module fuse replace
Fuel filter replace
Fuel pumps OK
Fuel pressure/leak down OK
Vacuum all hoses OK
Cylinder compression very strong OK
Spark plugs replace
Sparkplug wires replace
Distributor cap & rotor replace
Ignition coil Ok
Timing OK
Crankshaft sensor OK
Camshaft sensor OK
Ignition switch OK
Air intake sensor OK
Air mass OK
Starter lock out OK
LH-SFI module-salvage purchase replace
Cruise control/idle module-salvage purchase replace
DI ignition control module OK

I test and replace all these items and the car had me stuck for over 5 months. I was really looking for the matches and gasoline now

I spent countless hours on this forum and others researching the problem. Day and night I played with the car in my free time. The $tealership and Indy shops just want to much cash to look into the problem

No codes to use and I was pretty much sick of the car. Why would this M119 not continue to run. There was just no excuse for the engine not to run.

Conclusion: I scanned and scanned each module check OK even the original modules. After making several attempt to start the engine over and over again for several times with out fowling out of the spark plugs. I scanned the DI module and it was intermittent it no longer flash "no fault" and it barely respond. I finally decide to purchase a salvage yard EZL unit. I install the EZL and started the engine then all of a sudden the M119 begin running like a champ. The EZL did not give any codes but as it heated up it begin to fail and cause the engine not to continue to run. I feel that the ETA failure, Heat from the engine, or Bad ignition coil cause the DI ignition control unit to eventually to fail.

DRICHFL