turbo wiring woes

[madseb]

hi all im currently in the process of attempting to mate the wiring of a 1.4 340, and a 440 b18ft engine together.

currently I have:
+12v live from the battery (red) to power the wiring (existing loom feed to battery)
+12v ignition switched live (GREY) from switched igniton live to loom.
earth 0v (brown) from loom to engine/chassis.
a fourth wire that switches from 12v to 0v when the starter is activated. this wire is grey/white. and is show on the 440 wiring diagram as going to the 50 power line.

can anyone confirm weather this is correct, as at the moment im having to manually jump (activate using a 12v feed) one of the relays (I believe it is the fuel relay) to get the engine to spark.

im by no means new to engine wiring, but this has got me absolutely stumped. im led to believe the ecu may be blown, as it would seem its not telling the relay to activate, and liven up the fueling/ignition circuit.

also the mystery fourth wire, and its purpose has got me a little confused, and this could also be where the problem lies.

I have attached the wiring diagram im working from.



the fourth (suspect) wire is shown on the diagram as coming from terminal 4 on the ecu to the 50 rail at the top of the diagram.

any help will be much appreciated.

madseb

[Chris_C]

Do you mean pin (15? it's a bit small on the diagram and my 440 haynes is buried atm)

Relay B2 has a constant 12V on the coil and the ECU provides a switched gnd not +12V (i.e. it's floating until it's activated, then provides a ground), that then allows 12V to sit on the hot side of the coil for B12, where pin 15 (or whatever it may be) also provides a switched ground and activates that for the injector power feed.

Easy test, put your multimeter on continuity, then one wire on the battery negative and the other multimeter wire on that pin. As you crank it should go from no circuit to circuit.

[madseb]

hi chris,
thanks for the advice.
im a little confused as to pin 15?
the wiring diagram can be clicked, and enlarged if that's any help.

the test you described, should the pin going to the 50 rail be the one to carry out the test on, at the moment this is showing 12v, then 0v when cranked.

thanks.

[Chris_C]

Ahhh, ok, I hadn't noticed that

"ECU-B18FT" Pin 17, the symbol by that means switched earth so my guess was right. Ignore the relay for the test, multimeter continuity test between pin 17 and the cars ground with ignition off and ignition on.

Also, I don't see any connection to the 50 rail, everything goes to the 30 rail apart from the fuel and boost switched ignitions (pin 18 for fuel, 6 for boost) and the random pin 4 on the fuel ECU connection, there is another diagram that will show you what that this "rail" is powered by somewhere.

[madseb]

thanks for the heads up chris. ill attempt a test between the pins when i get a chance (possibly the weekend)

i believe the "rails" to be ignition positions? as they seem to tie in with the numbers on the ignition?

any thoughts?

[madseb]

any help with this? as im at my wits end with the wiring at the moment.

could anyone tell me, by looking at the above diagram, how they would tally to a 340 loom?

thanks.

[madseb]

might have made a bit of progress today.

I seem to have an extra pair of wires for this sensor thingy:






can anyone shed some light on what it is, or where it goes, it lkooks to be some sort of manifold sensor, temperature maybe?

there doesn't seem to be any sign of it on the loom diagram, or anywhere for it to attach to the loom?

thanks

[Speedy88]

Two coloured wires to ECU and the two red are ignition live? What do the two coloured wires read with ignition on?

[madseb]

sorry speedy you have lost me,

the two wires from the sensor shown in the above pic, go to the battery (hence the large open loop terminal) and the other dosn't go anywhere.

looking at the diagram, there is a temperature sensor that operates the auxiliary water pump (this is now on a manual override switch) so if this is the temperature sensor for the relay that operates the pump. i believe i can just remove it now?

thanks.

[Speedy88]

Possibly yes. Could they potentially be the feed to the electric cooling fan?

[madseb]

looking at the diagram the wires seem to tally up with the switch (a57) on the far left.

so I believe im possibly right, this is the temperature switch for the relay for the auxiliary water cooling pump..