Is it a MEFI 3 or MEFI 4? The only difference is the MEFI 4 has the oxygen sensor which helps with the surging at idle.
You can change it to the MEFI 4 but you have to buy the kit from GM. It comes with a new harness, computer, temp sensor and oxygen sensor. $600.00
Do you have the instructions for installing the ramjet. You probably can get it from the dealer or I might have a copy of it.
There is a seperate coil. It is black and has 2 connectors on it.
The distributor connects to the wire harness. One plug from the harness to the dist and then from the coil to the dist.
It does not have a crank trigger. All the connections were on the throttle body, ramjet, dist, knock sensor, temperature sensor.
We used the wire in the harness to the fuel pump.
It has 2 relays, one is a run relay, the other fuel pump relay.
On the plugs that go on the computer. They connect on either side of the computer so be careful when hooking it up. It will not hurt anything but the fuel pump wont run. I chased that for a while.
Here is a couple websites for some info and a GM troubleshooting manual.
This is older info,,all I could find at the time.
You can see the coil in this picture.
Here is a scanning tool. They give you a little tool to plug in the harness and count lights with the original kit. This is a seperate scan tool.
Here is a good manual to get. They also have one for the MEFI 3
Look in my photobucket under my signature. It has the 502 ramjet I installed in my buddys car under Marks car.