I think the coolant temp sensor is located in the t-stat housing.
Just what do you think your gonna do with it. I don't think the EZL uses temp corrected timing in 1987. I could be wrong though. Anything you do to the fuel system will be corrected for until until you exceed the adaptive limits. If you do that you will only succeed in burning more fuel.
The only way you can improve on MB's set-up would be with timing. (Short of major changes in the motor)
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician