Car shuts itself off

[SVX95]

Hi,
I'm brand new to this site and would really appreciate your help. I have an
'86 MB 560sec (US) which has suddenly started to just shut itself down. It will start right back up again but then shut itself down again after either a few seconds or sometimes a few minutes. My local Mech. is not an MB specislist and I would really like to avoid just throwing parts at the car.

Any help would be greatly appreciated. Thank you.

Leo

 

[television]

The fuel pump relay could cause this take it out and put a wire between pin 30 and 87

 

[SVX95]

Car shuts down

Thank you very much Malcom, but could you clarify a bit for me. Are the "pins" in the fuse compartment where the relays are located and are they numbered? Sorry, I'm obviously not a mechanic- but eager to learn.

Again thanks for your help, I will certainly give it a try this week-end (I keep the car at my week-end place).

Leo

 

[television]

I am not sure if it is 137 in the link,,as my other computer is off for the night.

The idea here is to make the fuel pump run all of the time, you could also remove a wire from a fuel pump, and join it up to the battery live terminal and if the car runs, then you are getting near the problem

The fuel pumps are under the passenger side rear wheel behind a plastic cover

http://www.detali.ru/cat/oem_mb2.as...&L=765.706&CT=F&cat=569&SID=54&SGR=045&SGN=03

 

[SVX95]

Wow- Thank you

Wow, I almost didn't click on to your diagram. I am really impressed and greatful, not only for your help, but for the depth of that help (I certainly wasn't expecting a diagram). Thank you (I will of course let you know how it goes).

 

[television]

I forgot the link for the relay, 137

http://www.detali.ru/cat/oem_mb2.as...&L=765.706&CT=F&cat=569&SID=54&SGR=045&SGN=03

If the car runs with the fuel pump pins 30 and 87 bridged, it should only be a matter of taking off the cover and re soldering the relay to the PCB

 

[SVX95]

Hi Malcolm,

I didn't get down to my 560 as planned this week-end (minor emergency kept me home), but I did go out and buy a fuel pump relay so that I would have it if that turns out to be the problem.

However I noticed that when I compared the MB part number I got from MB to the one in your diagram, my part is for the "...only applicable to retrofit/catalyst vehicles" The word "retrofit" throws me a little since the car was not retrofited, but came equipted with a catalystic converter. Does the word "retrofit" in this case just mean, vs. European models which did not require catalystic converters at the time.

Again, thank you so much for your time, help and education.

Leo

 

[television]

There are 2 different part numbers shown, you needed the one with the first number as 2 are shown.

Did not you try fitting a jumping wire from pins 7 and 8 of the relay multi plug

 

[SVX95]

Hi Malcolm,
In case I didn't mention it before, I live in the USA and my car was bought here and came equipted with a catlyctic converter as required by law. Since your chart is a European one, maybe from that vantage point any '86 MB with such a converter would be considered "retrofited"? The new relay I bought in a US dealership would be the 2nd one on your chart-but I think might be the correct one(I can double check that when I can actually get to my car and compare the two relays).
I will still do the wire crossing test before actually installing the new relay(I can't buy a new one down where the car is so I thought that I would bring one with me-can always return it if that's not the problem).
You mention crossing the #7 and #8 wires. That is a change from your previous post (crossing the #30 and #87 pins). The pins that I have on my new relay(hopefully they will match those on the old one) are: 32 15 87 87H
50 TD 30 87K 87V TF

So would I still cross the #30 and #87 (not #'s 87H, K, or V right? - I don't have any #7 or # 8 pins). So sorry for this long post but I really want to learn and understand. Thank you so much.
Leo

 

[television]

No not really a change,,the pins 7 and 8 are marked on the plug for the relay, the pins on the relay have different numbers, including 30 and 87, doing 7 and 8 opposite each other makes it easier

 

[SVX95]

Thank you again. Obviously I should have waited until I could actually "look under the hood" before asking you all of these questions. I'm keeping my fingers crossed for this comming week-end. I will of course let you know how it goes.
Leo

 

[SVX95]

Hi Malcolm,
I did finally get down to my car and unfortuneatly the Fuel pump relay is not the problem.

The fuel pump runs fine when the wires are bridged, but still shuts itself off- I was actually able to try a new relay and it too didn't make any difference.

I took the car back from the mechanic and will probably get rid of it-I just can't afford to keep "playing" with it when it is virtually never used anymore.

Again, thank you very much for being so generous with your time.

Leo