Thanks for the reply. I took out the fuel pump relay and then cranked the engine to clear it out. It actually started and ran pretty smoothly for 10 seconds with the relay out. I then put the relay back and started it. It ran roughly for a couple of seconds and died. I repeated this a few times and it seems to run well for a few seconds with the relay out. When I put the relay in, it starts for a second but is running roughly then dies. It also starts on starting fluid with the relay out. What does this seem to indicate? high fuel pressure? bad injectors? bad fuel pump relay? Again, thanks for your help!

It indicates that you are massively rich. The first step is to lean it out till it runs. Then if you don't already know you need to review the info for adjusting mixture electronically. That will not work untill you get a lot closer to proper mixture.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

I first turned the mixture screw about 1.5 turns counter clockwise. The engine then started and would run somewhat smooth at about 1500 rpm with some pressure on the accelerator. It would not idle. I then played with the mixture screw some and got the engine to idle (not as smooth as it used to, but it would keep running). If I turn the screw CW or CCW about 1/8 to 1/4 turn from this point it runs quite rough and starts to die. With the screw set so that it idles, any pressure on the accelerator causes it to die. Sometimes right after I start it the abs light is on and it runs rougher. Then the check engine light will flash and both lights will go out. It then runs smoother. A couple of times the o2 light came on for a short time. It seems like something has failed. Why would the mixture become that far rich just from letting the car sit and why if it is set so that the idle is reasonable, any pressure on the accelerator causes it to die. I read the service manual about adjusting the mixture. It says to pull off the purge line toward throttle valve housing on purge valve and close. Will that help with the adjustment? The final adjustment looks complex enough that I should probably take it to a shop, but it would be nice if I could get it to run well enough to drive it there. Any additional help will be appriciated.

The tasks you are performing are really diagnostic in nature. It sounds like you have a problem that is not going to be repaired with adjustments.

As the next simple test (if you haven't already), I would disconnect the EHA. The point in doing this is to eliminate any electronic issues. You mention OVP and other things you think are affecting performance. With the EHA disconnected you are running totally on the mechanical system (which does just fine once started - starting may be an issue - use the finger on the airflap). If I were doing this I would just pull the plug when it was running and see if it made any difference. It should not!!

I also would have been watching EHA current from the beginning and would have known what I would see by disconnecting EHA.

The possibilities as I see it for a huge rich mixture change are: control piston stuck up, airflow plate touching cone, fuel pressure too high, and way to much current through EHA.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

I got the car warmed up and idling at the same state as last night. Unplugging/reconnecting the EHA didn't seem to have any effect. It still wants to die if I press the accellerator and still runs a bit rough. Can you give me some pointers on how to check for the other possiblities you mentioned? Thanks

During the process of replacing the fuel pump, I had drained the old gas and put in 2 gallons of new gas with 1/2 can injector cleaner. Since my last post a couple of days went by, and I thought I would try it again. The car started and ran well while off idle. Since I had leaned it out a lot to get it to run before, I enriched the mixture and it ran quite well. Based on the previous list from Steve, my guess is that the control plunger had become stuck from the gas going bad and sitting. I think the new gas with the strong concentration of injector cleaner freed the plunger after a couple days. I also bought a book Bosch Fuel Ingection & Engine Management by Charles Probst. This really was helpful to understand how the CIS system works. You can get it from Amazon for < $20.