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Did I blow a Fuel Pump?

While changing my fuel filter, and the 2 copper "o" rings replaced with it, I noticed the lower fuel pump, outer "o"ring was also leaking (92 190e 2.6) takes 3 copper "o"rings. Removed outer bolt tightened inner sleeve bolt to compress center o ring, then new copper o ring and install outer bolt, tighten slowly, release C clamps on fuel lines......look for leaks no leaks. Reconnect battery, start engine...let idle....look for leaks. Small drops slowly forming, fuel pump outer o ring bolt....using socket wrench...tighten bolt a little more, almost there, use open wrench to hold fuel pump for last little bit. The moment the open wrench touched fuel pump, the engine stopped. I know, forgot gas cap (pressure). Turn over strongly, try to start, and die. 20 times. It was like someone shut off the key. checked fuses, over voltage relay, fuses look good ........please help..Rick

Reply to
r parris
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If it was running and you shorted the + connecter to the wrench..... you fried your fuel pump relay. It is NOT fused!

Reply to
Karl

Fuel filter reversed? Fuel pump is a roller vane type,did you squeeze it too tightly?

Reply to
CaptainW116

No, fuel filter properly installed. I didn't squeeze fuel pump, I was holding 2 pump/ accumulator frame as I was tightening fuel pump cap nut, a o ring. Fuel pump connectors have rubber L shaped boots on them, now found to be badly cracked. I Don't see fuel pump relay on list of parts for

1992 190E 2.6 . Goes from 190E 2.3 '87 to '93 190E 2.3-16 all....190E2.6 to '89 MAS control unit 190E 2.6 from '90 425.00 I'm screwed!
Reply to
r parris

Augh! I told you about the aviation form-a-gasket... the only way to solve that leaky problem... Seems like you may have zapped the fuel pump relay. Replace the fuel pump fuse... don't just look at it.

If you have service manual... it will tell you what pins you have to jump to test the fuel pump... once jumped... start engine... if keeps running, then it is fuel pump relay.

Reply to
Tiger

I only have a chassis manual and a Haynes Benz 2.3 '85 to '88 most parts apply. I Now find major changes were made in the 201 series 1989 to '93 end of series. (tragedy really focuses your attention) Stupid, to put a wrench on fuel pump without Redisconnecting battery. Is there a way to check out fuel pump operation before commiting to replace MAS relay. No fuel pump relay here. (just bought aviation form-a-gasket) whimper, sigh......Public library has 103 engine manual, and at least 40 Mercedes, and Bosch manuals

Reply to
r parris

You can buy rebuilt MAS relay... instead of the full price at dealer... go to mbcoupes.com and look under part supplier list for electronic rebuild... I'll check for pins tonite...

Reply to
Tiger

Check

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It shows you do have fuel pump relay... MAS is for like air conditioner stuff...

Reply to
Tiger

Tiger schrieb:

Normally it should be battery 30 to 87. Of course you can test the pump dirctly using a 3 m cable to battery dirctly.

Reply to
Roland Franzius

I remember having to remove this MAS to shut off fuel flow when I did a compression check. Black, 3x6 inch rectangular relay behind battery, with a knob on top you turn to make it pull itself down and seat. I forget now but it combines several functions into one relay.

Reply to
r parris

Went to Archives: Electrical troubleshooting manual N16 Engine control systems,.....After 1990 these relays went solid state, combined into MAS ..... fuel pump relay, air injection pump relay, transmission control points relay, A/C compressor relay, heater for O2 sensor, and some engine controls, But only in 2.6 201 series, 2.3 no change!

Reply to
r parris

MAS means Motor Aggregate System. MB combined the klima relay and fuel pump relay into one unit.

Reply to
Karl

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