Running L-Jet on the stand, What power needs to go to the relay board - Got it running! Options

[nditiz1]

As my parts come in for my L-Jet tune up, I'd like to start to plan out my test stand. Does someone have a link to a thread or just the answer of what power I need to send to the 14 pin connector to run the engine on the stand? Thanks!

Edit - See latest post on which wires were needed as a minimum.

[Superhawk996]

Here's a handy diagram to the relay board. I don't know who put this together but they sure deserve a (IMG:style_emoticons/default/smilie_pokal.gif)

I've been going though the schematic a lot lately trying to help Second Wind with his fuel pump & other electrical issues so had it handy. I don't know who put together this graphic but it is base off the factory manual diagram and schematics. I'm not a L-jet guy but as far as I know the relay boards didn't change between D-jet and L-jet.

Basically you need 12v power to pins 14 and 12 (14 pin connector) - these are direct feed to the relays which will in turn provide power to the ECU and fuel pump. Obviously you'll need the ECU and associated sensors injectors, L-jet wiring in place. Sensors are passive devices read by the ECU as inputs.

Pin 14 supplies 12v input to the fuel pump relay pin 30. Power from the relay leave on pin 87 and goes out to the fuel pump on pin 13

Pin 12 supplies 12v input to the power pin 30 of the power control relay. Pin 87 is the output from the relay which in turn supplies the 12v power feed to pin 85 (solenoid) of the fuel pump relay once the power control relay is energized. So the sequence is the power control relay has to be energized 1st. That provides power to the ECU. The ECU returns a ground to pin 86 of the fuel pump relay energizing the fuel pump relay solenoid.

Power (12v) to the coil comes in on pin 8 (of the 14 pin connector) and goes out on pin 7 (of the 12 pin engine harness connector).

Ground comes in on pin 10 (of the 14 pin connector)

Sorry -- lots of words. Study the diagram and it should start to make sense. Alternately maybe some body has a nice engine run stand wiring diagram for you. @nditiz1

The other engine harness signals you would want like tach signal are also called out on the diagram on the 12 pin connector that goes to engine / starter / oil pressure signal, etc.