Can anyone tell me where the fuel pump relay is located on my SEC?

Are there any special tools needed to replace both fuel pumps?

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

On my 500 SEC, it was in the rear of the fuse box.
The big relay that is NOT labeled 'klima'.

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-Josh
Testing the cheap Mercedes axiom, one bolt at a time...

In your car it's near the center of the car between the firewalls between the ABS brain and the Klima relay. It'll have Kickdown or the like on it. Maybe 6000RPM min too. Black 1" X2 1/2" by 3" tall approx.

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1986 Euro 500SEC "RUF" 9:1CR, "Rose"
1985 Euro 500SEC Cabriolet AMG Widebody
1982 Euro 500SEL "Blue"
2001 Texas Heeler (Aussie/Queensland X) "Sulphie",
2012 Queensland Red Heeler "Squeak"
Best dogs I've ever had.

Ok, I replaced the fuel pumps, and am using a known good Fuel pump relay, and it is still doing the same thing!!! Looks like the mechanic's diagnosis was wrong. UGHHHH!!!!! I did, however replace the OVP with a spare I grabbed at the junkyard, and it made it run quite a bit better, almost driveable, but still not quite "right". There is still a slight loss of power, but when you mash the throttle it takes off like nothing is wrong. I should also mention that it runs perfect, smooth and responsive for about 30 seconds to a minute, then it starts to bog down and run badly.

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

I had a similar problem and I found it was a cascading effect... I had bad ignition wires that threw off everything I replaced cap, rotor, wires, plugs, and coil, ground wire, and cleaned out the idle air control valve... if you have never done these things it's about time you do and it's not a loss even if this is not the cause. maybe your cold start valve is stuck open... look it's something simple... hopefully

Well the car is back at the mechanic's shop...let's see what he comes up with next!

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

Warmup regulator!!!! May be the culprit. The 30 seconds thing sounds like the WUR or the Cold Start injector. The gasket under the Cold start injector my be toast causing it to suck air. How about vacuum lines? Is the EGR hooked up correctly? does the Tempo Vac Valve work? Lots of thing screw up the Idle. If the EGR is actuating at idle it'll run like crap, almost die.

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1986 Euro 500SEC "RUF" 9:1CR, "Rose"
1985 Euro 500SEC Cabriolet AMG Widebody
1982 Euro 500SEL "Blue"
2001 Texas Heeler (Aussie/Queensland X) "Sulphie",
2012 Queensland Red Heeler "Squeak"
Best dogs I've ever had.

Wife's Maxima had symptoms nearly identical to what you described, particularly the parts about it (1) starting fine and idling fine for a bit and (2) bogging down on accleration. Injectors were replaced, CTS replaced and plugs, wires, distributor/rotor and coil checked out good. Turned out to be MAF sensor.

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1988 California version 260E (W124)
Anthracite Grey/Palomino
Owned since new and still going strong and smooth
MBCA member

Past Mercedes-Benz:
1986 190E Baby Benz
1967 230 Inherited from mom when she downsized
1959 220S Introduced me to the joys of keepin' 'em goin'

There are only 10 kinds of people in the world--those who understand binary and those who don't

On mine, a 1987 560SEC, the fuel pump relay is right below the windshield in the middle of the engine compartment.

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" We have nothing to fear but the main stream media itself . . . ."- Adapted from Franklin D Roosevelt for the 21st century

OBK #55

1998 Lincoln Continental - Sold
Max 1984 300TD 285,000 miles - Sold
The Dee8gonator 1987 560SEC 196,000 miles - Sold
Orgasmatron - 2006 CLS500 90,000 miles
2002 C320 Wagon 122,000 miles
2016 AMG GTS 12,000 miles

Got a call back from the mechanic, he replaced the fuel filter, and all is well. Apparently it was clogged to the point where it would no longer flow. He even gave me a demonstration with compressed air, and the filter would barely flow, and lots of dirt and chunks came out of it.

Change your fuel filters people!!

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

Did your mech offer any relief for faults misdiagnosed and work/parts done but not needed?

Seems that fuel filter would be the logical place to start rather than last resort.
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BTW, a similar temperature related effect on my 560SL (basically the same engine and control system) was isolated to the engine temperature sensor that inputs to the EZL. Ran good cold then went sour when warmed up.

Well, know he has the peace of mind, knowing that all of those parts have been replaced and are not likely to break anytime soon . . . .

__________________
" We have nothing to fear but the main stream media itself . . . ."- Adapted from Franklin D Roosevelt for the 21st century

OBK #55

1998 Lincoln Continental - Sold
Max 1984 300TD 285,000 miles - Sold
The Dee8gonator 1987 560SEC 196,000 miles - Sold
Orgasmatron - 2006 CLS500 90,000 miles
2002 C320 Wagon 122,000 miles
2016 AMG GTS 12,000 miles

Nope, he even charged me more than he had originally said he would. I ended up paying about $100 for the filter change.

__________________
Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

Is it finally running correctly? My US spec 380SE's CSV (Cold start valve) is inop but doesn't hamper the performance, except on start up (you have to give it a bit of gas). Hopefully it's fixed but it does sound like a faulty FD. The same thing happed in my 200TQ just pulling out of the driveway and driving up a hill and all of a sudden no power... Smelled raw fuel and car bucked like a horse...

__________________
"Why operate within the law when you can operate above it?"

MB roster
'85 500SE euro Ratrod
'92 500E's x2 / '94 E500 stored
'91 560SEC w/43K stored
'92 Cabby 16V OE 2.1 AutoX car
JDM RHD cars now.

Makes you wonder how clean that fuel is coming out of the pumps!

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)