Hi guys,

I bought a used lt8 for my S4 TII and I now have a question.

Everything was wired according to the wiring diagram with the help of my father ( which is an electrician BTW ) so I think that everything's ok.

BUT!!!

on the wiring diagram, it is written that only the RED and GREEN wire go to the LT8, and that the 2 other ones ( YELLOW and BLUE iirc ) must be grounded.

Here's the problem : The previous guy did NOT seem to ground those 2 wires. In fact, instead of grounding them on the body, he actually soldered them to other wires inside the shielded CAS wiring.

To add to my confusion, only one wire comes out at the LT8 plug's extremity and it's the BLUE. where is the YELLOW wire???

Also, That BLUE wire is inserted into the CAS plug that plugs into the LT8 when there's only supposed to be the RED and the GREEN wire according to the wiring diagram

So, is that situation normal?
How did you hooked up your 2 ground wires on your CAS?
Was there a BLUE wire on your CAS plug ( LT8 side )???

If CAS was wrong grounded by the previous user, ECU cannot get any ignition trigger? and if ECU doesnt get any CAS signal, it's not gonna fire the coils? and if the coils aren't firing, the fuel pump wont go on?

I dont have spark, I dont have fuel. Can this be caused by the CAS grounding situation?

Remember that miswiring is nearly impossible beside the CAS grounding situation ( it looked like we only had to plug and play, but after I took a deeper look, there are no ground on the microtech at the place the BLUE wire goes ) because I did it with an electrician

so please I wanna know your opinion on the subject.

thanks a lot guys!
l-p

**** EDIT : -with key "ON" GREEN and YELLOW light on
-With key "START" GREEN light on, YELLOW flashing

 

My coils receive power from the IGNITION 12V ( PINK wires )

but they dont seem to receive signal from the 3 GREY wires. its bizarre since I read that having the YELLOW light flashing during cranking supposed that the signal was ok.

Also, I wired my fuel pump from the relay on the 2 BLUE wires that come out of the fuel pump relay and resistor and go straight to the fuel pump ( refer to FSM's wiring diagram if you dont know what I'm talking about. ) is that correct???

 

you dont need to ground them they are grounded through the ecu as is the shielding, you just have to hook them up at the cas end and away you go,

the car will not start with out 2 signals from the CAS so replace that loom and the car should run

Dale

 

So you think that its a faulty CAS or a faulty CAS wiring???

 

if you only have 1 wire going into the ecu then it is the wiring from the cas to the ecu...

 

I actually have 3

RED, GREEN, BLUE

i'll double check that tomorrow to be sure...

I'll check also if those wire send signalif I spin the CAS manually...

 

The wiring diagram for LT8
http://www.microtechefi.com/IMAGES/w...4-5fuelign.pdf

And for LTX8
http://www.microtechefi.com/IMAGES/w...3BTS4-5ign.pdf

 

Thanks for the link man, but I already have the manual


I'll double check my ingnition trigger, that seems to be the trouble...

that pink wire hooked up to the fuel relay and coils makes me angry...

 

caliss de tabarnak de criss d'osti ( french cursing )

Seems my good friend ( sarcasm ) SMOKEN' sold me a broken ( or at least non functionnal ) LT8

green wire going to fuel pump relay is a ground into the microtech ( tim possingham from www.microtechefi.com explained this to me )

Even with the switch to "ON" I wasn't able to get the fuel pump running. I jumpered this wire to the chassis and OH here comes the fuel! So this means that I received a LT8 with a blown ground.

after manual grounding, I was able to have gas, I checked if I got spark by the same time.

I DIDN'T!!!

So I checked my CAS resistance, It was perfectly within specs. This proves that my CAS is actually working. My LT8's YELLOW light flashes when cranking. So this means it actually receive some kind of inputs...

Also, each of my coil receive voltage while cranking

it seems the microtech can't send any outputs to coils

i'm ******* pissed off!!!!