Intermittent stalling 260E

[85 DSEL]

My son drives the 260E and twice in the past two weeks he has experienced it stall for now apparent reason. No lights, plenty fuel in tank, etc. Could this possibly be fuel pump related? Where should I start with troubleshooting this issue (beside this post, of course!).

Thanks for your replies

[optimusprime]

May be the tachometer fault . If it as a short it will stop the pump so the car will stall .Re start and run again just to repeat again. Remove connection on the rear of tachometer and if it runs ok replace the tacho. But i would do all the usual things first . This is a last resort . Check all fuses .Put a little grease on the tip of every fuse and remove it after.Check also all earth points ,remove them, clean up conntact points on the body grease them also then refit. Let us know how you get on .

[85 DSEL]

Originally Posted by optimusprime

May be the tachometer fault . If it as a short it will stop the pump so the car will stall .Re start and run again just to repeat again. Remove connection on the rear of tachometer and if it runs ok replace the tacho. But i would do all the usual things first . This is a last resort . Check all fuses .Put a little grease on the tip of every fuse and remove it after.Check also all earth points ,remove them, clean up conntact points on the body grease them also then refit. Let us know how you get on .

I'll try to look into these ideas when I get the time! Thanks for your reply

[ILUVMILS]

Take a look inside the distributor cap........

[Rick76]

Did it stall when driving or when sitting idling?

[85 DSEL]

Originally Posted by Rick76

Did it stall when driving or when sitting idling?

He said he was slowing down to make a turn when it died...


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[85 DSEL]

Originally Posted by ILUVMILS

Take a look inside the distributor cap........

Looking for...? Perhaps a loose wire?


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[remotemark]

Take a quick look at the OVP and see if one of the fuses is blown.

[ILUVMILS]

Originally Posted by 85 DSEL

Looking for...? Perhaps a loose wire?


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Look for burnt contacts, corrosion, signs of arcing........

[85 DSEL]

Originally Posted by remotemark

Take a quick look at the OVP and see if one of the fuses is blown.

How many are there? I have pulled the small 10A fuse from the top of the OVP located behind the battery area. It was not burnt or broken.


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[remotemark]

Early ones had one fuse, later ones had two, interchangeable. Stalling at low idle or fluctuating idle rpms have indicated bad ovps for me on both of my M103 cars. If you can get hold of a known good one to try, it might worth the trouble. Also, and this is beyond my ken, sometimes the circuit on the board inside the relay gets broken and can be resoldered. you might find more information on that by searching the forum.

[85 DSEL]

Originally Posted by remotemark

Early ones had one fuse, later ones had two, interchangeable. Stalling at low idle or fluctuating idle rpms have indicated bad ovps for me on both of my M103 cars. If you can get hold of a known good one to try, it might worth the trouble. Also, and this is beyond my ken, sometimes the circuit on the board inside the relay gets broken and can be resoldered. you might find more information on that by searching the forum.

The OVP is sure tucked back under the the battery compartment! Not easy to get to. Does it simply lift out of socket our is there some other step to getting out? Thanks for your suggestion.


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[85 DSEL]

While changing oil on it last Saturday, I happened to notice that a pair of bent-nose long handle pliers that I must have laid upon the air cleaner when checking the OVP several days earlier had slid forward and become somewhat wedged in a position such that the bent-nose portion was stuck near the distributor/ignition parts at front of the valve cover! Top of pliers had a blue-ish, burned look as if it had shorted on electrical part. On up the handle, there is evidence that the serpentine belt had been rubbing as well.

Whew! Sure dodged a MUCH BIGGER problem had they fallen on down and tangled with the fan our somehow got between the belt and one of the pullys.


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[BenzEnthusiast]

The OVP relay and fuel pump relay are probably the cause of your problems. Both can be disassembled and repaired. There are usually a few broken solder joints that just need to be re-soldered. I usually re-solder all of the joints just to be sure that they are all good.

The relays can be a bit tricky to get apart, but you just need to be patient and use a few small flat blade screwdrivers to get the covers off of the relay's circuit board.

[Stretch]

Try the following

1) Disconnect the negative battery terminal for about 10 minutes and reconnect (by doing this you are clearing all error codes in the ECU)

2) Drive the car and see if the fault reappears (doesn't really matter if it does or not)

3) With OUT turning the ignition off measure the Duty cycle between pins #2 and #3 on the x11 diagnostic socket. If this is giving a continuous error code report back

Could be the road speed signal transducer (Could be other stuff - the point is to measure the error codes in the form of Duty cycle)