The V8 Owners Forum -

as some of you may have read before in another post (3.9 loom) that i had an engine and no loom blah blah blah well now i have a loom and all looks to be plugged in ok. But i have two pins open on the dizzy but no plug on the loom to meet it. I have read the "3.9 wiring diagram" post that a wire goes to the coil neg to tell it to fire the injectors but how does it know the engine position? i.e how does it know which cylinder to inject on? What are the 2 pins on the dizzy for? do i need to use my old lumenition and connect it to the dizzy? Thanks!

The ecu doesnt know where the engine is at any time and doesnt need to. The hotwire system is batch injection and not sequential or timed. Basically it fills the back of the inlet valve until it opens if that makes sense to you. Ecu wont connect to the dizzy. The pins will be for an ignition amplifier by the sounds of it. What model dizzy is it, some should have a black plastic unit on the side others are wired to an amp that sits under the coil in an alloy box.

i see....... so its kinda like wasted spark but with the fuel? Looks like i been stitched up and havent been given everything with the engine wen i got it. I looked at other dizzy pics and have noticed a little box on the side of other dizzys, this im missing! If i get a little black box do i need to run wires to it? do they go to just the coil?

There is a wire that goes fron the coil to the air flow meter - from memory a black one with a white stripe.

I was led to believe that when you turn on the ignition it will activate the fuel pumps for 3 secs then only when cranking / running will this wire send a trigger to the ecu to turn the pump on again

Tis may be the one you are missing

Ian

it depends on what dizzy you have as to how its wired. have a look here http://www.rpiv8.com/electrics-1.htm and see if you can identify yours.

Ian Anderson wrote:There is a wire that goes fron the coil to the air flow meter - from memory a black one with a white stripe.

I was led to believe that when you turn on the ignition it will activate the fuel pumps for 3 secs then only when cranking / running will this wire send a trigger to the ecu to turn the pump on again

Tis may be the one you are missing

Ian

Something like that. Goes to the negative side of the coil.

The plug with the wires that go to the distributor should be available from Rimmer Bros.

If the amp has a two pin connector make sure you specify the correct two pin plug.

Kevin.

thanks for your help guys looks like i have got to grips with this now. (I hope!) Will use my old 3.5 dizzy with the lumenititon all ready on the car as its all wired in, this should be ok? I have the dizzy numbers written down but not with me now as someone asked eairler.