Rick Mixture Caused by Overload Relay

[DvZ]

Hello everyone. Trying to understand what the overload relay controls. My 560SL failed inspection because it was running rich. My tech told me the rich mixture is caused by a bad overload protection relay. Does anyone know how this relay causes the mixture to be off? Thanks.

Originally Posted by DvZ

Hello everyone. Trying to understand what the overload relay controls. My 560SL failed inspection because it was running rich. My tech told me the rich mixture is caused by a bad overload protection relay. Does anyone know how this relay causes the mixture to be off? Thanks.

it isn't that the relay its self will cause a rich mixture, but rather if the relay is defective it may not send power to the fuel injection control module, if the module looses power there will not be any fuel control, which will likely cause a rich mixture.
a defective ov relay will also cause idle problems and abs issues.

[ctaylor738]

If your OVP relay is failing, you should get an ABS light and a high idle. I would look into replacing the o2 sensor if you don't have those symptoms. If the sensor is weak, the computer will think the mixture is lean and richen it.