hey guys, awesome website been stalkin it for ages gettin heaps of good info, but now ive got a question i havnt been able to get an answer too. just tuned my vl at work and driving along it starts to backfire and splutter then will die, its happened twice now, itll drive fine for a day or so then does this, ive changed the dizzy, the coil, done a timing belt and some other little things, got 3 different manuals tellin me very similar things but it still does this. Mods are a custom plenum with an xf throttle body intercooler adjustable fuel reg (we'checked to see and fuel pressure is okay around 40psi) bosch 044, surge tank, and some other unrelated mods. anyone know what i should be checking? i do drive to pretty hard too but it should be okay, in my experience these motors can cop a thrashing? cheers heaps for the help

Still sounds like crank angle too me maybe when ya changed dizzy it had a **** one in that too or ignition module

try a fault code test? could narrow it down

CAS is fine it came on an exchange dizzy which was tested at work, codes coming up are coolant temp sensor and speed sensor, other code is 43, wtf is that? where is the ignition module on vls? it seems if i adjust the dizzy timing, itll go right for 2-3kms but then itll detonate and die

Afm plug or even afm. Does it blow black smoke off boost when it does it? Coolant temp sensor could be doing it aswell. It's telling the ecu it's cold when it's hot n over fueling it.

afm was changed, previously the code for it came up and i replaced it, i havnt tested the plug though, specs for it would be in a manual? only thing i havnt changed is the coolant temp sensor and if thats fried it would be causing the problems because it seems to cut out and die as soon as its hot

have you checked your pug leads my vl used to do same thing and i tried everything in the end it was a dead plug lead would run beautiful of boost but under boost coughed and spulttered realy bad

As other mentioned. 1-CAS. 2-ignition leads. 3-spark plugs. 4-stale fuel, clogged fuel filter, dirty injectors.

um here we go does fuel pressure rise when you rev up if not fuel reg/pump running standard computer you could have a short running from ignition to computer i had this did what you said

fuel filter

how did you find out where the fault in your wiring was? if it was that, it only happens when it begins to get warm like 20 mins of driving..

yeh thats sounds like a crank angle sensor it may of been working before u put it in but it could be ***ed again it just happens as mine was like this till i changed it again ---------- Post added 11-03-12 at 12:55 ---------- this is exactly what mine was doing struggling after 20mins when the cas heated up ---------- Post added 11-03-12 at 12:56 ---------- either that or the plug on top of cas when it heats up the wires move should check that aswell

Quote: Originally Posted by holdenvlt [View Post] hey guys, awesome website been stalkin it for ages gettin heaps of good info, but now ive got a question i havnt been able to get an answer too. just tuned my vl at work and driving along it starts to backfire and splutter then will die, its happened twice now, itll drive fine for a day or so then does this, ive changed the dizzy, the coil, done a timing belt and some other little things, got 3 different manuals tellin me very similar things but it still does this. Mods are a custom plenum with an xf throttle body intercooler adjustable fuel reg (we'checked to see and fuel pressure is okay around 40psi) bosch 044, surge tank, and some other unrelated mods. anyone know what i should be checking? i do drive to pretty hard too but it should be okay, in my experience these motors can cop a thrashing? cheers heaps for the help Have you checked the intank fuel pump/intake hose? sometimes pressure in the lines can be misleading as it can be air from pump cavitation. Also must either fix the CTS fault or unplug it and live with a 4 minute ECU warmup cycle (if using a 3TA/3TM)

this is how i found out i took it too my mechanic whom has a eccs diagnosis computer and he was checking injector pulses on the diagnosis computer and there were some wave crossovers and it looked pretty distorted so it then went to the auto elecs to look for shorts in wiring as it was hapening over all 6 injectors hope this helps

1,3 and 5 are connected together. same as 2,4, and 6. Some original photos have not been recovered yet.

learn something new everyday i spose if you could get your hand on a oscilascope you could proably work it out too thanks for the that info even though its not my thread so your saying there are 2 circuits for firing the injectors off 1,3,5 of 1 circuit and 2,4,6 off another so pretty much batch firing

yep, two batches. Some diagnostics computers will not diagnose low impedance injectors correctly. Injector firing waveform is very different to a high impedance injector and even more so if batches are connected together.

yeah my mechanic i go to has the old eccs specific diagnostic computer its a big brick. lol i was only talking about waveforms because when i had the same problem with mine it looked like a hole bunch of distorted waves super emposing each other on each injector through all of them and would only happen when warm so i was thinking cas changed 5 of them so ive got spares now. and it was simple under dash wiring to the ecu and non engine bay wiring related what do you expect wiring in these cars can be up to 25years old its no suprise we dont have more wiring issues and problems popping up

too true... the biggest one I see next to the cracked CTS plugs is the 3x earth wires on the drivers side engine mount. Over the years the get either left off from the bolt or moved when the must stay together on the block bolt and kept nice and clean with contact to the mount/block.