another microtech question

[piggy]

hey guys ive just finished wiring my ltx12s up to my 1j

i dont seem to be getting any fuel into the cylinder head i can hear the fuel pump running, i have fuel coming out of the return line, i did a resistance check they are wired up correctly but when i tested for voltage there was none any idea on what it could be?

im running 800cc injectors, hks 264 deg cams but the ecu came off one with bigger injectors and cams

any help would be great guys cheers chris

[YLD-16L]

You've got 12V to one side of the injector and the ECU switches -ve side.

So your saying you've not got a 12V supply to them? Wiring issue or blown fuse??

You can put the Microtech into test mode (it will fire the injectors without running the engine or fuel pumps) and it'll fire all the injectors so you can use a stethoscope or screw driver to listen to each injector and ensure it is pulsing.

If you confirm they are getting a 12V supply and still won't fire in test mode and you are sure the wiring is correct then the injectors may be seized and need a light tap to free them up.

The last set of brand new Sards I ran were all seized straight out of the box and needed a tap while in test mode to get them firing.

[The Witzl]

I'll echo what Shane has suggested.
Make 100% sure you have got the wiring correct before continuing any further.

Eliminate all possible causes of the issue one by one, and soon you will find your problem.

[piggy]

cheers for your help guys im thinking that i may have wired the injectors around the wrong way (all tho i was under the assumption that it didnt matter with injectors because they were pulsing is that correct)

but i will have to wait until the weekend to double check

cheers chris

[MWP]

all tho i was under the assumption that it didnt matter with injectors because they were pulsing is that correct

Injectors dont have a polarity, they dont care which is ground, and which is 12V.
But thats not what the guys above are talking about...

Almost all ECU outputs switch the ground connection on and off.
So to switch a light with the ECU for example, you hook one wire of the light to 12V and the other to the output of the ECU.
The ECU will then turn the GND connection on & off, which will turn the light on & off.

[piggy]

cheers mate ill have a look on the weekend to double checkk they are getting 12v (which im sure they are as they seem to be pulsing )

[MWP]

Are you using the 1J's factory engine loom, or is it custom?
If using the factory loom and you are getting ignition power elsewhere, the injectors should be getting it too.

If youve got fuel pressure, and your fuel injectors are ticking away, the problem is probably somewhere else.

[piggy]

its a custom loom, i migth give the injectors a tap like yld said will see how i go on the weekend

[The Witzl]

I personally would take the plugs off the injectors, turn the car onto IGN, and check that 12V is present on one pin to each injector (use a test light, with one end of the test light connected to earth)

Then if thats all good, reconnect the 6 injectors. Connect one side of your test light to a fused 12V wire (Ign wire is good), and connect the other end of the test light to the other wire of one of the injectors (NOT the 12V wire).... and fire up the car. The test light should flash, indicating that the injector is being pulsed.

Thats a good start

[piggy]

cheers mate will try that tommorow/ sat morning and will let you know how i go

cheers again chris

[piggy]

problem has now been fix (the car runs!) thanks for all your help guys! the problem was i was a total idiot when wiring it up, i thought the plugs which went to the injectors from the microtech were a +12v and then has to wire up an earth, so i ended up having 2 earths instead of a +12 and earth as the plus on the injectors are the earths

took me about 2 minutes to fix the problem lol

cheers again guys

[piggy]

thanks for the help again guys heres the vid of her first start