cars been down garage, and theyv had RAC diagnostic thing onit aswell.

 

the injectors are not working, not clicking, and not getting power/earth.

 

ive done a NA to TT conversion, kept the NA loom. using the TT ECU

 

 

ive changed the connections on the front 4 injectors.

 

the ECU is not showing any error codes.

 

 

the injectors were working fine before i did the swap, as the engine is from my old car, as is the ECU.

 

do i need a new loom? im about to give up on the car :(

With no 12v power at the injectors any neg signals from the ecu are not going to work, so we need to find where the power supply has failed, this is a battery feed supply and is live all the time so a single fail point is causing all of the injectors to not work.

 

Fuses are located in the supply and these would be the next thing to check, if the fuse is ok then the fuse input supply requires tracing etc.

 

You could always run a tempory feed to one of the injectors and it will automatically link to the other 5, be careful to not mix the 12v + and earth as the ecu will not like that!

 

Seriously I think you have just a niggly issue that has you all frustrated and sometimes its best to take a chill and start at the begining, it will be worth it in the end.

 

Jeff TT

 

thanks mate, yea i need to relax, sure itl be resoved in the end.

 

can you advise where the fuses are you speak of?

 

i was thinking that today, could i not just run brand new wires from the injectors to the battery/ground?

thanks mate, yea i need to relax, sure itl be resoved in the end.

 

can you advise where the fuses are you speak of?

 

i was thinking that today, could i not just run brand new wires from the injectors to the battery/ground?

 

I had the same issue but with the coil packs and spent 2-3 weeks trying to find it and Jeff's advice was a godsend. I had to bridge connectors to make a tempoary feed which proved that the fault was in a power supply wire, after proving that the fault was found quickly and proved to be a broken wire!

 

The fuses I think Jeff is talking about are in the engine bay on the drivers side at the back, there are about 6 I think.

i know the fuses, ones next to the fuel pump fuse.

 

so on the injectors/injector connections, there are 2 prongs.

 

im asuming 1 of these is posotive & 1 negative yea?

 

my CAS is working to send the signal to the injectors (as have spark)

 

so if i just run sperate power/ground to them, should work?

(thats if i cant find a broken wire)

On the injectors yes 1 +ve and 1-ve

ok cheers.

 

so if i sort a 12+ & 12- to each injector, will it work?

 

i mean will they inject fuel when they supost to?

 

the standard connectors from the loom wont be connected then, is there any signals sent to the injectors from that? or simply a constant 12+ & -

 

 

just trying to understand how it works to understand the problem.

 

think were getting closer now :)

ok cheers.

 

so if i sort a 12+ & 12- to each injector, will it work?

 

i mean will they inject fuel when they supost to?

 

the standard connectors from the loom wont be connected then, is there any signals sent to the injectors from that? or simply a constant 12+ & -

 

 

just trying to understand how it works to understand the problem.

 

think were getting closer now :)

 

You need to retain the existing negative feed, as thats the trigger signal from the ECU, and supply a new 12v feed to the positive side.

 

I think you can get away with just supplying a positive feed to one injector as the rest are linked, double check for a positive current with a multimeter on the rest after connecting up one.

Edited June 24, 200916 yr by Yowser

You need to retain the existing negative feed, as thats the trigger signal from the ECU, and supply a new 12v feed to the positive side.

 

ok. how do you establish which one is the + and -, both on the injectors them selves, and the connector?

 

 

ive changed 4 of the connectors on the injectors themselves, so its obviously a further up in the loom, closer to the bulkhead. (if there is a break even)

 

 

Do i defo need to use the negatives from the ECU? surely the injectors dont mind where they receive a negative from? or isit the ECU that will be looking for them to be earthed

ok. how do you establish which one is the + and -, both on the injectors them selves, and the connector?

 

 

ive changed 4 of the connectors on the injectors themselves, so its obviously a further up in the loom, closer to the bulkhead. (if there is a break even)

 

 

Do i defo need to use the negatives from the ECU? surely the injectors dont mind where they receive a negative from? or isit the ECU that will be looking for them to be earthed

 

If you connect them both up to a postive and a negative then the injectors will just dump the contents of your fuel tank into the engine constantly.

 

The negative is not a straight earth, its a trigger wire. Its how the ECU tells each injector when to open and close.

right ive got you, thanks for clearing that up.

 

so use all the existing negatives from the loom.

 

put 1 brand new posotive to 1 injector, and that will give power to the other 5. (or put posotives to all the other 5)

 

 

posotives are easy to do, just need to check the negatives. if one of the negatives are broke, will that mean they all wont work?

 

 

so ive either got no posotive coming from the ECU to the injecors, or no negative coming from the ECU.

 

or both coming from the ECU, and getting lost by a break in the loom possibly

Do the +ive first, if the car works you know its that supply. If not then look at -ve

each negative is seperate

 

Edited June 24, 200916 yr by Yowser

Z32, the easiest thing to do is to remove the number 1 injector connector, then:

 

1) Set meter to "volts" and make sure the meter probes are connected to the volts inputs and not the amps inputs on the meter (easy to mix up!). Check the meter shows +12V or so when you connect it across the vehicle battery.

2) Connect the black meter lead to the battery negative terminal and connect the red lead to the wiring harness injector connector pin with the white/black striped wire

3) You should see +12V on the meter

 

If you do see 12V, the problem is with the ECU drive signal (ground signal).

 

If you don't see 12V, then get a length of insulated wire and poke the bare end into the injector connector pin with the white/black wire, then connect the other end to a fuse (5A fuse would be fine), then connect the other side of the fuse to the +ve battery terminal. If the fuse blows straight away, there is a short in the injector wiring somewhere.

 

If the fuse is OK then this will then supply the other 5 injectors with a +12V feed and it should start and run (on 5). In this case, you have a break in the injector wiring somewhere.

 

You need to be careful not to connect 12V to the ground (ECU) side of the injector connector, because this would blow the ECU. So if you find that both wires on the injector are coloured W/B, then choose a different injector.

 

Ok lets follow the diagram to help you sort out why you have the problem you have and how best to deal with it

 

Relays A,B,C all take their coil or swithing 12v+ from the same source as the injectors as noted by D

 

Now as your saying you have spark that proves that line is powered up, however as you do not have power to the injectors then that would suggest a cable fault at position D

 

As mentioned by others rather than searching for a break in a cable some, wire in a new supply to the injectors making sure you use a fuse in the circuit.

 

 

The neg triggers from the ecu do not take kindly to shorts or cross polarity so be careful when connecting up.

 

 

Jeff TT

ok thanks dudes, sounds like getting more progress, i will be trying this on the weekend.

 

 

only thing im worried about is mixing up the + and the - of the wire to the injectors. the coloring is different on some the wires.

 

is there a way i can check which one is what?

 

and likewise on the injectors themselves?

Hang fire and will get you all the colours.

 

Jeff TT

Red and black is the common live for all engine sensors,coil packs etc.Jeff will correct me if im wrong :D.

the injectors have got 12+

 

 

there is no negative signal tho.

 

but how do i now sort that? surely not all 6 negatives have gone?

 

or do they join at one place?

 

the ECU workt fine before the swap, so it cant be that...

you tested for negative signal while trying to start the car ?

you tested for negative signal while trying to start the car ?

 

ive got the car back tomo,

 

and ive got my own volt meter.

 

the garage/RAC have told me there is 12+ to the injectors.

 

 

Legrath, do you mean that there will be no signal when not trying to start it, but some negative signal when trying to start it?

 

 

 

the electronic diagram seems straight forward posted bu Jeff, but looking at the loom is different,

 

 

as a last resort i could run each negative from the injectors to each PIN on the ECU separate, but sure theres a glitch in the loom some point in the engine bay, suggestions where/how?....

Have you chercked the connector is properly seated on the ECU?

Have you checked the connector is properly seated on the ECU?

ive got the car back tomo,

 

and ive got my own volt meter.

 

the garage/RAC have told me there is 12+ to the injectors.

 

 

Legrath, do you mean that there will be no signal when not trying to start it, but some negative signal when trying to start it?

 

 

 

the electronic diagram seems straight forward posted bu Jeff, but looking at the loom is different,

 

 

as a last resort i could run each negative from the injectors to each PIN on the ECU separate, but sure theres a glitch in the loom some point in the engine bay, suggestions where/how?....

yes, there will only be a negative signal when the engine is turning over.

 

The problem will not be each individual wire to the ECU, so no point rewiring them individually.

i will try tonight, but im pretty sure the garage would have tested for negative signal wen turning the car over, as thats why theyv said its the negatives on the injectors.

 

so how do i sort this then? if i rewired the 6 earths to the ECU how woudnt that work?

 

stil confused why all 6 have gone? (PS ECU workt fine before, and ive removed and re-sit it just incase)

Stupid question but you haven't got any type of immobiliser wired in, have you?

 

Also when the engine is turning over, does the fuel pump run?

its got an imobiliser on it yes, but you have to disarm that, or you dont get ignition.

 

the fuel pump can be heard priming wen u turn the ignition on.

 

 

its gota be something like the pump ECU not relating to the main ECU?

 

 

legrath & Jeff sort it out:p