rb20det starting problems...

[kwazza11]

pin 43 is the start signal, it needs to be connected to your start circuit so it gives power when you crank it. that way the computer knows your cranking it over and it needs to feed it spark so it'll fire. your original engine should of had a signal coming from the ign switch.

[tandy ass]

kwazza11 - not entirely correct, i'll try to elaborate.

When you're cranking the starter motor is drawing well in excess of 100 amps of current from the battery, this in turn drops the voltage typically to 6-9 volts. This reduces the spark intensity and may not trigger the fuel injectors correctly due to insufficient voltage. Pin 43 is used to tell the ECU to open the injectors WIDE and charge the coils as much as possible to ensure the engine starts after 1 or 2 revolutions of the motor.

If you dont connect it, the engine will start fine when warm but when its cold it will generally take 10-30 seconds of cranking before it fires and it will cough and splutter into life. It will not harm the motor to leave it disconnected and the engine will run fine after its started.

You will get spark so long as you have correct input from the crank angle sensor (it uses 2 regular wires and 2 shielded co-axial wires in the loom) and the correct voltages on the ECU. I've pointed out in another thread here which pins need 12v and which ones need grounding. If you dont have spark then you will have either (in order of likeleyhood) -

Incorrectly wired the power to the ECU/grounding to it.
Faulty ignitor module (the device that sits at the top rear of the engine between rocker covers, on the coil cover plate).
Faulty cam angle sensor.
Faulty ECU.
Faulty loom.

The air flow meter, detonation sensors, any of the air control sensors, throttle position switch or any accessories do not need to be connected to get the engine started.

Cheers

[kwazza11]

tada! and unknowningly youve just solved the very last problem with my conversion!! Bozz your a freak.

guess i gotta go recheck that connection because you just explained to the T my engines symptoms when trying to start it.

btw that last post was a good guestimation anyway :p

[tandy ass]

LOL I've done enough of the conversions so I'm sort of getting the hang of it now

[kwazza11]

hmmm.. mabye not.
seems the symptoms are the same but i guess its a different problem.
cause i checked the wiring and i've connected the black/yellow from the ecu to the black/yellow #6 wire from the dash loom.
it gets power when cranking so i'm assuming its doing its job, however i'll get my hands on a multimeter and check it properly when i go back to work.