fuel pump relay issue - Benzworld.org

jwc · 02-08-2008, 05:53 PM

I have a 86 mb 560 SEL that will start but dies instantly thereafter. If I hotwire the fuel pumps, the engine will run but at a high idle. I've checked all the wiring to the fuel pumps. I've replaced the fuel relay with a supposedly checked used one. Which pins on the relay do I jump to check it? Or is there something else I should check. Any advice? Thanks, JWC

livefreeordie · 02-08-2008, 06:36 PM

welcome

you might want to post this question on the W126 board, you will get a much faster response. Good luck

rsanders · 02-15-2008, 03:57 PM

Had similar problem with my 74 450 sl,don't know how close these are related,but if you can hear the pump run when you turn the key on,most likely it is either the cold start valve or thermo time switch, but I really don't know how close these to auto's compare.

**Teutone** · 02-15-2008, 05:01 PM

Welcome jwc and rsanders, to take advantage of all the forum features, please re visit the 'Welcome to the Forum' tutorial sticky on top of the W126 page, as well as the two DIY stickies.
It will show how to search the forum, and even has a link to the Russian MB site where you can run a VIN#. The forum archive has a wealth of information write up's re your topic.
Good luck

Please complete your profile with a location and car mod (see sticky). It makes it easier for member to offer advice.

Serintek · 02-16-2008, 02:02 PM

Quote:

Originally Posted by jwc

I have a 86 mb 560 SEL that will start but dies instantly thereafter. If I hotwire the fuel pumps, the engine will run but at a high idle. I've checked all the wiring to the fuel pumps. I've replaced the fuel relay with a supposedly checked used one. Which pins on the relay do I jump to check it? Or is there something else I should check. Any advice? Thanks, JWC

Got exactly the same problem 2 weeks ago. Here weather passed fromn -20 to 5 above, and with melting snow and rain, realy probably got some humidity in it. Original realy from 1988 560 SEL.

Next day took it off, got it inside for 4 hours, slammed it gently on the bumper twice and put it back in place. Everything worked well. Got the car back from work to home 50 miles, and then.... ordered a new one. The relay, I'll keep it for spare in case...

Good luck