engine and drivetrain Standalone EFI wiring help

[Guest Anonymous]

I have a 73 2002 tii project that has had a troubling issue as of late. The car has a built M10 with a T3 turbo. I am running a standalone efi system (034 efi) and have been having an issue with there still being a signal in the wire from the ignition switch to the relay panel for the ecu after the ignition is off, because of this the relays will not close and the car continues to run with the ignition switch off. If I hold a test light against the spade connector that the switched 12v signal is being pulled off of, the engine will turn off as desired. While I am well versed in this particular efi system and what it needs to run, I am at a loss as to why it will not turn off.

My first question is, what could be causing the ignition switch to stay hot once closed, and why would a test light solve this problem.

My second question is, what is the minimal number of wires nescessary to turn the engine over?

I know I need to keep my switched 12v connected in order to start the car, but what else is nescessary to turn it over. I currently have only a large (4rt on the wiring diagrem) red power feed wire, and a black wire to the starter connected with hopes of removing any variables from the scenario. However now the car won't start, it makes a noise simular to when a batter has a low charge.

I will try to get some pictures up once I get onto a computer with a better connection, however any insight would be greatly appreciated. This has been a long project, and having the car start up and idle nicely..... then not turn off has been very frustrating.

Thanks in advance for any help!

[Guest Anonymous]

I apologize, I just read the forum rules, I have used turbocgt as a username in the past. In accordance with forum rules I will use Jared H. in the future.

[ar_kid]

The relay only needs a few volts to hold it closed,

If you can measure how many volts you have at that switched 12v signal or

try giving the relay a flick and it might just let go.

[jimk]

I pull my switched 12V from fuse #10. Switched power passes thru a 3A fuse the serves 3 users, the ECU, the fp relay control and inj relay control. Ecu grounds the fp and inj relay control sides. Ecu is in turn grounded to complete the circuit. There is no relay to the Ecu and so when the ignition switch is off, there is no power to fuse #10 and the Ecu shuts down.

[TobyB]

wild guess- what turns your alternator

off when you switch the car off?

Alternators can 'self- excite' and cause all sorts of troubles like this.

t