'89 260e engine keeps dying
 

Hello folks,

Our '89 260e has developed a problem. She runs great for about 3 to 5 miles then her engine cuts out. Specifically the engine runs rough when we come to a stop and shuts down upon trying to accelerate/leave the intersection.
This has happened twice to my daughter while turning right after a complete stop. Upon returning to retrive the car a few hours later it starts right up and we are able to drive her home without any issues.
The car has recently had a new fuel filter installed.
Any ideas as to what may be the problem?
I would hate to concede defeat and pay $100/hr for something that we may be able to reslove at home.

Thank you in advance!

Have you checked for spark and fuel when it won't restart?

Sixto
83 300SD can be yours
98 E320 wagon

Fuel pump relay . .Or fuel filter .Check fuses in the fuse box ,clean them one at a time ,and replace . The ovp relay can cause this problem it sits at the rear of the battery .Pull the plastic liner out ,you will see one relay in a cover with 2 fuses on the top ,check them out .

The fuel pump relay would be my first suspect. If you have a distributor, check the cap and rotor for wear, they can cause some really annoying problems when they finally go south.

Car started fine cold. Idled for about 10minutes without issues. Checked out the fused relay behind the battery no issues there.
Turned car off, washed it and now it will not start. Never a dull moment...

Did you remove the ovp relay with the fuse or fuses on the top .Give it a shake .If it rattles its shot . But some can be resolderd inside . My car was 3 years old .It keept stoping and not stsrting .The garage said to the owner [before me ] they would fix it .The garage removed the head .Replaced it after a refurb , with new gaskets . Well she still started and stoped . Then they changed the ovp relay .It fixed it for good after £1000 bill for head refurb that did not need it .

Yes - consider what Sixto said. Tag along with some spare fuel in the truck. When it stalls, after pulling over, pop the hood. Pull top of air cleaner cover off. Pour in a very small amt. of fuel into fuel distributor. Try to start. If car runs for a sec. or two; then dies, you have a fuel delivery issue.

Easy things first...
 

Based on your short description, is it safe to assume that you have done just a basic level of maintenance (fix when broken)? Some 1989 cars already have the OBD I system (Diagnostic Trouble Code), refer to what the codes are telling you to address.


Here's my very basic (not a comprehensive list), relatively cheap parts and DIY fix check list I refer to whenever I pick another MBZ (9- W124's, 14 times overall since 1990). If I'm not absolutely sure that the part isn't 100%, then I replace it (but I keep the old part as an emergency spare).


I would think that your trouble lies within the first 5.


1. Voltage regulator: $15, replace it just because. (Is the ABS light also intermittent?)
2. OVP: $15, same as above
3. EHA: $100 for good, tested, used one with a decent warranty, if it's leaking from one of the weep holes, replace it
4. Fuel Pump relay: $25, replace
5. Dist Cap, Rotor, plugs, wires: $100 total, replace
6. Fuel filter: $20, replace unless you know for sure it's less than 2 years old.
7. Air cleaner: vacuum it, make sure you can see light through it
8. Oil and filter change: $30, you want to see what comes out when you drain it
9. Transmission oil and filter change: $40, same as above
10. Radiator Flush, Fill + Thermostat: $50, same as above

You can bridge the fuel pump relay for testing - see this thread
Ways to bypass Fuel Pump Relay on 300E - Mercedes-Benz Forum

It is possible to remove the fuel return line to the tank . You will see a metal pipe exiting the fuel distributor .Thats the one that needs loosening .Do this after it stops ,no fuel in there then its FPR or pump.

No need to rebuild the engine, or change a million parts. When was the last time you gave this car a tune up?

Spark plugs every year
Cap and rotor every 3 year
Wires every 5 years

Sounds to me like you have a classic ignition system failure. Change your ignition system with good quality parts (like Bosch or better) and move on with your life.

This sounds heat related -- runs fine when engine is cold, stalls when hot, then runs after cooling off.

Before doing anything else, check the crank sensor at the back of the engine/bell housing. If it is badly worn, with exposed wires in the cable, that is your culprit. (I had the exact same problem when I had my 260E)