My 260E idles at about 600 rpm and the "Economy" needle is in the red. If you have A/C on and start from a stop, it hesitates and sometimes cuts off. Without the A/C on it hesitates also. The exhaust pipe inside is very black and smokes even at idle. It's getting terrible gas mileage now. I've changed the air filter but don't know what could be causing it. Any ideas?

Has the battery been jumped lately?? You might want to check that over-voltage relay.

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Benzmac:
Donnie Drummonds
1992 500E (very soon I hope
1981 280GE SWB
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

I'm sure it has been since I had to put a new battery in recently. Can you tell me which relay that is and I'll replace it? Thanks Benzmac.

quote:

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Originally posted by Benzmac:
Has the battery been jumped lately?? You might want to check that over-voltage relay.

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The overload relay is mounted in the area behind the plastic cover that sits right behind the battery and against the firewall. It is a silver relay with a clear plastic cover on it that has a fuse in it.

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i had mine replaced recently with the updated version - with two fuses up top.

I really appreciate it. I'll give it a try.
Thanks abunch.

Joel, Did you have the same type of problem and did replacing the overload relay take care of it?

quote:

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Originally posted by joel:
i had mine replaced recently with the updated version - with two fuses up top.

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my problem was high and erratic idle, and hard starting (hot or cold).

when was the last time you had a tune up? fuel filter replaced? if i were you i would do these maintenance first before anything else.

jason:

yes, it solved my problem. my idle is steady and the car starts fine.

if your car passed all the checks, why bother with the new relay? i too am firm believer of preventive maintenance, but based on my experience and readings electronic parts are not included. it either works or don't. you just have to pay attention to any abnormalities to your car operation that may be symptoms to failure.

i see you only got 60K on your 89 car. wow, that is still break-in period for MB. cheers.

I replaced the over voltage relay with no change. It is getting progressively worse. Now it idles at 400, smokes (black) badly and misses at idle. Any suggestions?

quote:

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Originally posted by Benzmac:
Has the battery been jumped lately?? You might want to check that over-voltage relay.

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Lots of problems with overvoltage protection relays, but they only affect idle and cold running mainly. It seems you have a real problem. I would check the fuel pressure first. The fuel pressure regulators stick and cause rich running to stalling conditions from over-pressuring the system.

If you have good pressure I would verify closed loop lambda control by watching the current flow through the EHA (electro-hydraulic actuator). This is the sole electronic mechanism for mixture correction. It gets technical from there on. Let me know when your ready to test.

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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

I checked the Lambda according to Benzmac (9-3-1999) and came up with a reading of 80 - 84%. I checked it twice and both times the same reading. I don't know what that means but that's what I got.
I tried a new O2 sensor but didn't have any luck. I then started disconnecting some sensors to see if anything changed. Every one I disconnected had some impact on the running of the engine. When I disconnected the Pressure Actuator, nothing changed. Could this indicate a problem with it?

quote:

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Originally posted by stevebfl:
Lots of problems with overvoltage protection relays, but they only affect idle and cold running mainly. It seems you have a real problem. I would check the fuel pressure first. The fuel pressure regulators stick and cause rich running to stalling conditions from over-pressuring the system.

If you have good pressure I would verify closed loop lambda control by watching the current flow through the EHA (electro-hydraulic actuator). This is the sole electronic mechanism for mixture correction. It gets technical from there on. Let me know when your ready to test.

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[This message has been edited by gilbey (edited 06-25-2000).]

[This message has been edited by gilbey (edited 06-25-2000).]