More bits from the net
According to my 1980 Pontiac FSM, the operation of the EMR module is part of the C4 Computer Controlled Cataytic Converter system.
1980 Pontiac FSM Page 6E-33, referring to Fig 6E-47 (which is only a picture of the ECM mounting in the car), reference only the 5.7L "R" (Olds) 350 V8.
"...The EMR module has the capability of retarding the engine timing 10 degrees during certain engine operations to reduce exhaust emissions. During other engine operations, the module functions the same as a standard HEI module. The terminal "R" on the module is connected to the ECM and retard is accomplished by an internal ground. The timing is retarded 10 degrees only when engine coolant temperature is between 19C (66F) and 54C (130F), with thottle opening position below 45% and the engine speed above 400 rpm...."
As I think I noted above, the car I snagged my EMR module was a 260 Olds V8 powered Cutlass, 1980. I got the vacuum switch as well, but could not determine it's operation, so I assumed it was defective. My guess would be OEM operation non ECM was strictly to reduce timing at high vacuum conditions to reduce N2 emissions. Being Pontiac didn't use the 260 (they were stuck with the Pontiac 265), I don't have any info on the 260 usage (anyone with an 1980 Olds FSM??). Being the 260 was a lower cost car, likely they were able to make it work ultra cheap with a vacuum switch only. If they got it certified, in 1980, ECM's weren't required yet. 1981, they were. And IIRC the 260 died in 1980, none in the 1981 model year.
Call me TJ unless you would rather spell out 73eldoconvert
St.Paul/Mpls MN USA
73 Eldo convert... mostly stock w/Megasquirt TBI
93 Mustang convert, 96 Suburban 6.5 TD, 81 Riviera 5.7 diesel, 13 JettaSportWagon TDI