KE Jetronic Blues -- Help?

[Benz Sage]

Last fall I bought a clean 86 190E 5 speed for $850.00 with about 175k miles on it (speedo is broken). I am impressed with the quality of design and balance of the vehicle, but the motor has some ticking noises yet seems to be strong. I’ve read the threads of many Benz sites and believe it is a collapsing valve lifter. It seems to also have higher than normal radiator pressure yet no white smoke or overheating.

I put four or 5 thousand miles on it until it failed after filling up at a Flying J Gas Station last January. The temperature outside was about 10 degrees F, and after fueling it up and starting it, I drove the car about 300 yards out of the driveway when it started to act like it was running out of gas. A lot like it got a shot of water and had frozen up. It stalled and rolled the side of the road.

I was able to restart it and would idle fine but when I applied throttle to the clutch, it backfired, had a terrible ignition timing knock, black smoke and I had to pump the throttle to keep it running, as it appeared to be in “limp” mode. I drove it to another gas station down the road, and had a flatbed truck it home and dump it in a snow bank. Earlier this summer, I tried starting the car, and the car would not fire at all. According to a Mitchell Mechanic’s manual of that era, its symptoms point to a bad ECU.

The description of the 86 crapping out sets the premise to my trouble shooting. First thing I did was change the fuel filter (Bosch brand) by the fuel pump and accumulator, under the gas tank. I also put in a couple of bottles of Isopropyl alcohol in case water in the gas tank was the problem. I siphoned some gas out of the gas tank, and mowed the lawn with a half gallon of it, and the mower ran fine. I also bought 2 tested-used ECUs from Ebay, swapping both of them with the original, and that didn’t fix it (the price was right and will label and bag them for the parts box).

I was able to get the 2.3L to fire. I poured a little gas into the throttle body and it would run (with no power) until the gas was consumed. Then I had someone use the butt of a screwdriver press on the silver disc attached to the air metering part of throttle body, and the car would run, but smoked like crazy, and loaded up.

I bought a Fuel pressure gauge with adapters that work with the KE Jetronic fuel injection system and tested the fuel distributer test point (pressure side) It measured about 47 psi after turning on the ignition switch. Upon shutting the ignition switch off, a static pressure of about 40-41 psi remained, so I assume the accumulator is in good working order. Testing the injector side of the distributer, 31 psi was the reading. The only thing I didn’t have time for was a timed volume flow test, but it is obvious that there is some kind of impediment leaning the mixture

I also removed the fuel distributer and replaced it with a running 1988 190e fuel distributer (since it had the same Bosch part number on it) and the symptoms were the same. Since the car ran fine prior to filling it up, where would I look for points of restriction if some dirt got passed the fuel filter? Is there some type of electronic component in the 86 KE Jetronic system that would be a probable cause? Before I pull the tank, I would like to exhaust all other avenues of probability.