Are the CELi and MPI relay linked??

[LT1andDSM]

My car doesn't start but I notice with the key on sometimes the CEL will appear with some clicking from the MPI relay.

 

[steve]

Depends on what CEL your getting. It also depends on what model DSM you have.
Since your profile is messed up I can't give you any more infomation than to say there are at least two CELs that relate to MPI relay problems.

Steve

 

[LT1andDSM]

I have a 91 GSX. The car won't start unless the CEL comes on with the rest of the cluster lights before you start the car.

 

[steve]

If the CEL light doesn't come on when you first turn the key on then the ECU isn't booting up.
That could be a problem with the ECU or a problem with the MPI Relay. It's had to say right now which it is because the ECU turns on the MPI relay when it sees the ignition switch go to RUN and when the MPI relay turns on it brings the ECU out of it's power down state.

I'd check the ECU caps first and see if they have leaked, then I'd check the MPI relay to make sure that pin 8 goes low when the ignition switch is turned to RUN and that power is applied to pins 4 and 5. If pin 8 doesn't go low the ECU needs repair.

Steve