Vy v6 supercharger engine splutter

[blowncaprice96]

Hey guys.
My vy v6 supercharged ecotec is haven issues.
It will start and idle fine every time but when u give it some acceleration in park/neutral or underload it starts to splutter and carry on. Seems to be when boost starts to come on at around 2000rpm. You can drive it at idle and will go but any load then problem happens. I don't think it is a ignition fault as it had new coils, plugs dfi module. leads have been checked. and new fuel filter. I have checked fuel pressure at the rail and it's 45psi doesn't go up or down no matter what u do. There is no engine light on at all. When it is spluttering there is a bit of blackish smoke from exhaust. Any help would be great.

 

[Aaron6.93]

Jump on to Envyous Customs - Holden Commodore Diagnostic Software grab an ALDL cable and Advanced Engine Diagnostics.... This software will display DTC's (current and history) and allow you to clear them... That being said try running the engine with the cam position sensor unplugged..... The CPS is responsible for sequential injection, without it the engine will run fine but will be operating on a banked fuel injection model (like the pre ecotech buicks). A faulty CPS can cause the PCM to see a signal intermittently, (on - off - on - off at random intervals) resulting in the PCM activating and deactivating the sequential injection mode. When this happens the engine will have a hiccup. This is a free test, that's why I suggest it.... if the engine stops sputtering with the CPS disconnected I would look into replacing it ~$50 new. If not plug it back in and look somewhere else (DTC's!! DTC's!!!!) btw DTC 48 and 49 will be set in the history due to disconnecting the CPS.

 

[delcowizzid]

what plugs did you fit and what gap

 

[blowncaprice96]

Hey so they are the supercharger NGK plugs with a 1.1 gap. And the only codes it had where in history 49 and 47
I replaced the cas and cam sensor and now it will idle fine all day but if u give it even 1% throttle it has a loud knock and will not rev up at all.
Is it possible the balancer was damaged on removal and now causing this knock? Because the bolt was very tight and had to use a hand impact wrench.
Any help would be great as this has been goen on for a few weeks and making it hard for my wife to get to work each day.

 

[Aaron6.93]

The balancer is probably fine. They are usually on very tight. (It is keyed though.... You did line up the crankshaft key with the balancer right?) If you could take a video of your situation it would help us to understand what's happening. Also the plug gap should actually be 1.3mm. Given that you replaced the CAS and cam sensor and you still have problems, you may want to look into the dfi module. The CAS and cam sensor are both connected to the dfi module and they've been replaced so we can assume they are not the problem. DTC 47 is "18X reference signal missing" this signal travels from the dfi module to the PCM through the light blue/black wire of the dfi module harness. It is used by the PCM to improve ignition timing accuracy during crank and at engine speeds of up to 2000 RPM. Consider that both your DTC's trace back to dfi module, this would be where I would look next.


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[blowncaprice96]

The dfi module was replaced with all 3 coils only 3 months ago with Delphi. I have check the wiring to the dfi and retentioned the terminals and found no light blue/black wire from dfi module. I have taking a small video of the noise it is making but am unsure how to post it.

 

[Aaron6.93]

Sorry, the wire colour I referenced is found at the PCM not the DFI, alas it is irrelevant as I'm sure your wiring is intact. As for the video, youtube would be your best bet. Just upload it to youtube and post a link. I'm scratching my head here.... I have a strong feeling it's a faulty DFI module.... I understand that you have replaced it but things like this can happen. I've just recently returned a genuine Delphi DFI module after only 7 months of use because it developed a fault. I don't want you to go out and spend any more money, especially if it is not the DFI, I have access to spare parts for this kind of engine as I have two in my garage at the moment, so checking if my DFI module was the problem literally only cost me 5 minutes of my time. Try and find a spare module, talk to some wreckers maybe they will let you borrow one if not, I think you'll have to bite the bullet and send it to a mechanic.

 

[blowncaprice96]

Ok so I had a spare dfi module and put it on and now car runs mint. So I went out and brought another brand new Delphi one. Couldn't believe there last one only lasted 2 months. Thanks alot for all ur help I really appreciate it

 

[Aaron6.93]

Good to hear you got it all sorted.


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