380SEL won't run

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drew56cus
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380SEL won't run

Post by drew56cus » Sat 21 Apr, 2018 6:06 pm

Hi all,
I have a 380SEL here that will not run. It just cranks over. Not getting 12V to the fuel pump. When I put a separate 12V supply onto the fuel pump, the car started. I thought it was perhaps a blow fuse, but there does not seem to be any fuse labelled as the fuel pump. I saw Ozbenzheads guide to the relays, is it likely that the fuel pump relay is faulty? Any info on the following would be handy:
- where can I find the supply end of the fuel pump wire so that I can check continuity? (I presume it is black + red + white like it has been for decades?)
- how do I test the fuel pump relay?
- are fuel pump relays fixable, or do you have to replace them?

Also, any tips for getting into the boot and fuel cap? The central locking is not working so I am locked out of these parts, and can't figure out how to get in. Using the key on the boot lock does not do anything.

Thanks,
Drew
Drew
'65 220SE 4.5 Frankenbenz finnie :)
'65 220SE/C (#1 project - Tenorite grey)
'64 300SE/C (#2 project)
'66 250SE/C (#3 project)

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Ivanerrol
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Re: 380SEL won't run

Post by Ivanerrol » Sat 21 Apr, 2018 8:37 pm

There's a FPR relay but depending on the year of your car is dependent on it's location.
Plenty of junk yard spares.

here's an image - shamelessly stolen off BenzWorld.
ac relay out.jpg

To get into the boot. Squirt some Graphite (recommended) or WD40 or into the lock. Use the spare key to manipulate the lock. persevere with it - it's eventually open.

After you get in then Watch old Kent.
The fuel filler door release works off the same pump. There's also a manual overide on the fuel filler door. When you remove the plastic boot covering , by feel you will fine a little pull switch which will release the catch on the fuel filler door.

https://www.youtube.com/watch?v=GPXR7JzAo4s
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W211 - E240
W204 - C280
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W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
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W123 230
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W140 420SEL
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Lance
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Re: 380SEL won't run

Post by Lance » Sat 21 Apr, 2018 9:27 pm

Either fuel pump relay is faulty or ignition trigger box. If the box doesn't tell the FPR that the engine is turning then it won't turn on. Use multimeter to check for signal from the box when turning over by connecting to the appropriate sockets on the FPR plug.
Regards,
Lance Smart

W114 280E 5 speed manual
W123 280E

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AMG
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Re: 380SEL won't run

Post by AMG » Sun 22 Apr, 2018 1:26 pm

Pull the fpr apart and resolder the pins like I had to. I think I posted about this back in about 2008/9 when I had issues with the fpr cutting out the fuel supply. I'll dig up the link and edit the post when I find it.

viewtopic.php?f=10&t=5556

FPR has the white X on the side in my first pic in that thread.
Current:
1987 560SL 4sp. auto Signalrot "Stella"
1987 190E 2.3-16 5sp. man. Blauschwarz "Hermann"
1992 300CE-24 6sp. man. Perlblau / Iceblau "Gretel"
1992 Range Rover Classic 4sp auto Ardennes Green "Oswald"
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1986 560SEL Anthracitgrau "Schultz" - In Mercedes Heaven
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drew56cus
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Re: 380SEL won't run

Post by drew56cus » Mon 23 Apr, 2018 9:26 pm

Thanks all. The car is an 82 model so the FPR was in the fusebox. I bridged across terminals 7 & 8 so the pump would run and the car started (though it ran rough). I did not get a chance to do any other checks, but at least I could move the car into the shed.

I did not manage to try graphite in the boot lock so that will have to wait another day - I was hoping that once the engine ran I could build up vacuum and open it, but also, no luck. The central locking does not seem to work.
Cheers,
Drew
Drew
'65 220SE 4.5 Frankenbenz finnie :)
'65 220SE/C (#1 project - Tenorite grey)
'64 300SE/C (#2 project)
'66 250SE/C (#3 project)

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Ivanerrol
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Re: 380SEL won't run

Post by Ivanerrol » Mon 23 Apr, 2018 11:24 pm

unfortunately engine vacuum doesn't operate the central locking or the fuel filler door - completely dependent on the electric pump in the boot.
W211 - E240
W204 - C280
Departed
W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
W116 450SEL
W140 420SEL
W210 E240, E240
W209 CLK 240
W201 190e 2.6 (ex U.K.)

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Astro-Benz777
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Re: 380SEL won't run

Post by Astro-Benz777 » Thu 03 May, 2018 6:59 pm

Ivanerrol wrote:
Mon 23 Apr, 2018 11:24 pm
unfortunately engine vacuum doesn't operate the central locking or the fuel filler door - completely dependent on the electric pump in the boot.
To be a little more specific.....
Under the MDF lid that covers the spare wheel, inside the spare wheel well, on the drivers side, in the corner towards the rear of the car there is a big foam casing over which a metal bracket sits....looks like it's there to make the spare wheel fit in better/easier or the like.
If you remove the metal bracket (2 x 8mm bolts from memory) you will see that this foam casing (usually black or grey) opens up (like a book) from one side. The contents is your central locking pump, it will have a round electrical connector & a (usually Yellow) vacuum hose.
The reason for the foam and metal bracket is to muffle the noise and vibration.
W126's truly were the last real Benz in my opinion! :occasion5:
FORMER FAMILY:
1989 300SE (W126) Midnight Blue, Blue/Grey Interior (Gearhardt)
1982 380SE (W126) Thistle Green, Tan Interior (Sherman)
CURRENT DAILY DRIVE & BELOVED FAMILY MEMBER
1984 280SE (W126) Thistle Green, Tan Interior (Hilda)

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