John Robinson
Gone but not forgotten
I believe you put an MSD unit in place of the opti. On the opti there was a wire connector on top of it. What did you do with that wire connector. Did it reconnect to the MSD unit. The reason I ask is what I saw on your video looked an awful lot like how my car ran with that connector not making good connection. On the opti with that connector being right under the heater hose connection when it blew up it watered down the connector and the car would backfire and sputter and run if I feathered the throttle but mostly it just would stop. Also that connectors ground wire goes to the same ground bundle as the TPS. If you look at the information on open and closed loop you will see that the ecm ignores that circuit in closed loop. When you start the car the ecm wants to be in open loop and that is when it wants input from the TPS, Water Temp, and the MAP since they all go to a common ground bundle I would look there first to see if you have a bad ground bundle. When the engine gets to a predetermined temperature the ecm goes to closed loop and no longer needs the TPS, Water Temp or MAP input since it switches to the O2 sensor to maintain fuel and spark. I am not an electric engineer but it seems to me that if the car runs without the memcal in it is being forced to run in closed loop. I base that on the fact that the memcal is programmable read only memory and so I think that is the unit that governs which loop the car is in. By now all of the connectors and wires have been handled several times and the results with this old wiring could be that some are broken. Which could be the cause of you trouble.