fuel problem

[youvalt11]

I have a recurring issue with my 1992 Mercedes 400. After a 20 minute drive, the fuel system stops working, the car stalls and stop, and cannot be restarted for 2 hours,and there isn't spark in the plugs, Then its start and , after driving again for 20 minutes, the same thing happens. I cannot seem to figure out what the problem is. the Fuel pump is new ,the Fuel filter is good ,no Vacuum leak or Ignition problem.

 

[gsxr]

Have you checked the resistance of the CKP (crank position sensor) which plugs into the EZL, when the engine will not start? Compare to the cold readings (usually 800-1000 ohms).

 

[nocfn]

GSXR - that was a huge problem with w126 4.2L models. Running fine, get to temp and BAM nothing but death. That CPS cable was the issue there heading down to the flywheel. Cannot remember if it was bad coax cable or if the heat over time just rendered the bad connection. But a standard issue problem with the w126 4.2L V8 after 20 years. Replaced cable and the problem was resolved. YMMV

 

[youvalt11]

Thanks for the detailed answer. I am going to order the CPS cable now, I really hope this will solve the problem. I have been struggling with this issue for a month now and haven't been able to find a solution

 

[youvalt11]

GSXR - that was a huge problem with w126 4.2L models. Running fine, get to temp and BAM nothing but death. That CPS cable was the issue there heading down to the flywheel. Cannot remember if it was bad coax cable or if the heat over time just rendered the bad connection. But a standard issue problem with the w126 4.2L V8 after 20 years. Replaced cable and the problem was resolved. YMMV

Thanks for the detailed answer again -There two camshaft position sensors in the car according to PELICAN parts front and rear of the engine,As I am ordering the parts from a country outside the US, I want to know which of the two sensors I need -part number is 0-261-210-085
002-153-13-25 - thank you

 

[gsxr]

You need the REAR crankshaft sensor which connects to the EZL. Assuming you have a W124 400E, this sensor is Mercedes part number 003-153-49-28 or 003-153-50-28. Don't get a cheap one... OE/Genuine is preferred.

The front crank sensor is only for diagnostics and the wiring dead-ends into the 11-pin diagnostic socket near the EZL. This front sensor was deleted on facelift (MOPF2) models. The engine runs normally without it.

 

[nocfn]

I guess I wasn't clear - this GSXR is right, this would be the unit from EZL to the FLYWHEEL.

 

[youvalt11]

You need the REAR crankshaft sensor which connects to the EZL. Assuming you have a W124 400E, this sensor is Mercedes part number 003-153-49-28 or 003-153-50-28. Dont get a cheap one... OE/Genuine is preferred.

The front crank sensor is only for diagnostics and the wiring dead-ends into the 11-pin diagnostic socket near the EZL. This front sensor was deleted on facelift (MOPF2) models. The engine runs normally without it.

View attachment 161467

I guess I wasnt clear - this GSXR is right, this would be the unit from EZL to the FLYWHEEL.

Thank you both for the detailed answer - i order the Genuine ,and let you know if it solve the problem