S10xGN
12-16-2004, 05:08 PM
I found out something about Julio's AlkyControl and Ken Mosher's boost harness - you cannot run alky without the MAT plug (harness side) being plugged into the boost harness. The reason being when Ken designed it, he took his ground for the MAP sensor from the MAT harness instead of the TPS harness. The AlkyControl tap needs to see ~ 1.67V (key on, engine off) at atmospheric pressure. If you look at my diagram, you can see what happens when the MAT interface is disconnected. The ground goes away, the MAP trigger (wire "B") goes to 5V, the AlkyControl thinks it's at max boost and injects full time whenever the ignition is on!
The simplest fix would appear to be running a black wire from terminal "C" on the TPS shell (inside the conduit with the tan wire) to terminal "A" on the MAP connector shell. These wires are factory (S666) spliced anyways. Terminal "C" from the TPS, terminal "A" from the coolant sensor and terminal "A" from the MAT sensor; then returning to the ECM on pin D12.
This would allow a user to read air temperature - or - boost (by choosing which harness to plug up) and NOT affect the alky signal on the MAP. It will also return (TurboTweak) Eric's process of changing parameters within the chip back to what he had intended and wrote in the instruction sheet.
EDIT: I blurred out Ken's 'secret' parts for his protection...
HTH,
Russ
The simplest fix would appear to be running a black wire from terminal "C" on the TPS shell (inside the conduit with the tan wire) to terminal "A" on the MAP connector shell. These wires are factory (S666) spliced anyways. Terminal "C" from the TPS, terminal "A" from the coolant sensor and terminal "A" from the MAT sensor; then returning to the ECM on pin D12.
This would allow a user to read air temperature - or - boost (by choosing which harness to plug up) and NOT affect the alky signal on the MAP. It will also return (TurboTweak) Eric's process of changing parameters within the chip back to what he had intended and wrote in the instruction sheet.
EDIT: I blurred out Ken's 'secret' parts for his protection...
HTH,
Russ