VX Calais V6 Ongoing DFI/Ignition Problem?

[Immortality]

There are a couple of earth points on the engine that the PCM uses for it's base references, One is on the back of the passenger side head and the other on the front of the drivers side head on the stud that also holds a water pipe fitting. I've seen a few on the front looking rather average with a bit of corrosion.

If the fuel was dirty it may pay to pull all the injectors out and check the little filter baskets at the top of each injector, maybe some crap has gotten into the tops of the new injectors.

 

[Trevor loves holden.]

Vacuum hose hasn't falling off under carbie has it? No Christmas lights under the hood at night from leads? PCM has good earth? Was the BCM u changed have the same serial numbers?

 

[accentstencil]

Vacuum hose hasn't falling off under carbie has it? No Christmas lights under the hood at night from leads? PCM has good earth? Was the BCM u changed have the same serial numbers?

VT-VX don't have a carby.

 

[Trevor loves holden.]

VT-VX don't have a carby.

Well throttle body, still similar.

 

[Dak]

If all else fails and by looking at whats been done so far I'd be looking at trying another PCM

 

[Trevor loves holden.]

If all else fails and by looking at whats been done so far I'd be looking at trying another PCM

ERG valve ok, the egr is an electronic valve not vacuum...they do carbon up
and works something like a solenoid . it is part of the EFI system The Maf and 02 sensors are part of this
the current opens and closes the valve to let the heated unburnt fuel /gases come back into the inlet manifold to be recylced

PVC valve ok?

Sound like best thing to do is sell it.

 

[Skylarking]

... Sound like best thing to do is sell it.

He did; to his dad

 

[Trevor loves holden.]

Do you have the original PCM? Did you match the serial code?

 

[Immortality]

ERG valve ok, the egr is an electronic valve not vacuum...they do carbon up
and works something like a solenoid . it is part of the EFI system The Maf and 02 sensors are part of this
the current opens and closes the valve to let the heated unburnt fuel /gases come back into the inlet manifold to be recylced

Well kinda, but not.

The EGR stands for Exhaust Gas Recirculation and really has nothing to do with unburnt fuel, rather the purpose is to dilute the intake charge with an inert gas but as a by product you get carbon which long term makes a mess of the intake.

The EGR valve could very well be the culprit but I don't have much experience with them as my vehicles don't have em

 

[VFCalais2017]

Hi everyone,

I see there's been some further discussions into this matter! Thanks to everyone for their input and suggestions and sorry for the late reply.

Vacuum hose between throttle body and valve on rear drivers side of engine had been replaced. Metal pipe from EGR to plenum has also been repaired. Wasn't the fault though...

Decided to go back to basics...

I did some trial and error diagnostics last week. I didn't check codes or anything, just swapping parts from my Dad's VS Commodore (which is running perfectly)

It turns out that the problem was something so simple... a failed DFI module!

Although the mechanic had replaced it with a brand new one last year, it failed again. Not sure if it was a faulty unit from manufacture or the brand (unbranded) This time I will replace it with a branded unit. It's currently running a good second hand module for testing. All week the car has been running smooth as silk with no rough idle! You can't tell the car is running when it's stopped at the lights!!!

Just goes to show that you can't overlook work that has already been done. Sometimes it can come down to faulty parts or failure of the same.

Lol Selling the car wasn't an option as I have done practically everything to this car and it still looks and drives like new. If the problem couldn't be resolved, it was going to be deregistered and parked in the shed. Eventually I'd just pass it down to my children the same way my father and his father did with their cars. Thank goodness for their foresight otherwise we wouldn't have our original family cars today (HG Kingswood Ute and Premier Sedan). I'm on my third car now (VF Calais) but still own each car I've had since I got my license

Thanks again for everyone's input on this. Sometimes these problems get the better of us and we can't nut them out on our own. I greatly appreciate everyone's assistance.

Hopefully this thread will assist others with similar problems.

Cheers