I noticed my problem when traveling to the California mountains on July 4th weekend. As I hit 2000 ft. or so, I began to notice significant power loss. Once I got to 4500 ft., I had to turn around and find a place to park the car for the weekend, as I had almost no power left. I was able to make it the 5 hour journey home later that weekend, but experienced intermitant pwr loss on the fwy, sometimes traveling 70 was fine for an extended period, and sometimes the car slowed to 45. At first I thought that this might be the result of extremely poor gasoline, as the problem started almost immediately after filling the tank. So when I got home I drained what remained in the tank, replace the fuel filter and all of the neighboring fuel hoses which were old, cracked and leaking. While I finally got rid of some lagging fuel leaks, I still had the intermitant pwr loss problem. I subsequently replaced the fuel relay, but this did not help. As I have mostly been driving around the city I left the problem for quite some time at it seemed manageable around the city. But I recently started noticing an odd smell, and when checking into MercedesShop I saw a sulfer like smell can sometimes point to a clogged Catalytic Converter. So today, I had a muffler guy cut the pipes so we could look into the Cat, and it was clean and clear, no clogs. I recall others discussing the O2 sensor as a possible culprit for power loss. Any ideas from the group? I can really use some help in fault isolating this issue as my plugs are only about 6 months old, my distributor and cap is about 18 months old, the injuectors and pumps are also about 18 months old. Just not sure where to look in to next. Your thoughts are appreciated. Steven

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Steven
1989 260e

I would monitor fuel pressure. I would also monitor EHA current, but control is bound to be defective from your statement.

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

Stevebfl,

Thank you for your reply. Please excuse my ignorance, but what is EHA current? And I am not sure I understand what you mean when you say "control is bound to be defective"?

Thanks again.

Steven

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Steven
1989 260e

Time for the archives.

EHA current = the current flowing through the electro hydraulic actuator. EHA current is the mechanism of control.

You can not be in control and have the driving condition you describe. So looking at it is not necessarily going to tell you anything. Read in the archives about monitoring and adjusting the fuel control system. Monitoring it from the point of failure could indicate the problem.

In other words, the system must achieve control - closed loop! First step could be to establish control or find out why not. If control can be established at low load (idle say) then watching it as control is lost can indicate the problem.

But as I said originally I would monitor fuel pressure because if that is your problem you will have to be good to catch it through monitoring control.

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