VT V6 Failed to Re-Start After Stalling

[boombaby]

Hello, Any/Every!


I'm gettin' there. Patience!

The fundamental issue is that I have been trying to nail-down a Commodo VT V6 Ecotech
"stalling" issue. (We love those don't we!)

I will be asking each of you to give an opinion - BUT - rather than getting 10/20/50
people providing 10/20/50 different "things" I will be happy if 1/2/3 different
diagnoses become the serious contenders. (I hope I explained that well enough.) Later,
I will explain exactly "WHY" I'm asking for your advice/help this way, now.

Some Background...

On various occasions, in other posts, I have mentioned a couple of my VT issues. However,
since I will be making this as the main/direct thread about them, I will briefly describe
the problem(s) and my diagnostics so far.

Main theme... "Sudden stalling, after which VT fails to start immediately (ie WILL
re-start after a waiting period)". This is not a consistent condition on every drive;
it occurs out-of-the-blue, sometimes weeks/months apart.

In recent months I have been dragged off into bundles of other critical activities so I
have not been able to attend to this enough. (Fortunately, I have not had to rely on the
VT for many trips.) However, on last Saturday I had to do several short hops, but on the
2nd hop it failed to start after being parked for about an hour; and on the 3rd hop it
stalled on the way back home. (I'll get back to those moments, shortly. The rather odd
outcome from those events became the motivation to seek your advice/input now.)

Quick background/ on my efforts so far.
1. 2016, bought VT with 161k's for a low price.
2. Always ran well - but I never maintained it. (Save the criticism; I know it's slack!
This is my first Fuel Injection - and I thought it would be much easier to repair if
problems arose. Turns out DFI works better if it is maintained constantly - using
bucketloads of money. Tonnes and tonnes of money. Yes; that's a very weak argument
BUT it's the only one I've got!)
3. Recently, at 175k's, the "stalling" issue raised it's ugly head. And it is pretty
ugly. DFI (and the GMH design) is my new learning curve.
4. Cleaned MAF; replaced air filter, oil, alternator, battery. Purchased Vident scanner
which is showing the vehicle is running just within limits, but on the "rich" side.
At the moment that (alone) does not prompt me to a solution.
5. After checking all sensor activity and clearing codes the VT seems to settle on code
?-47-? "missing 18x signal". [I know that COULD be pointing directly at the CAS, but
I have also read that it could be a sign of failing/failed power packs or connections
(etc) too. From memory, I think that's right.]

However, I DON'T want you to focus too much on that stuff at the moment; I only want you
to keep it in mind when I tell you about last Saturday.

So, in terms of ME narrowing down the "stalling" issues, here's where I'm at:
1. It could be the CAS.
2. It could be the fuel filter and/or fuel pump.
3. It could be one (or more) of the DFI module or coil packs. [Someone told me
that after the car stalls feel each of the 3 coil packs with the back of fingers
because it can reveal that one is excessively hot - and failing/failed. (Well,
I have one hot, one intermediate, and one OK.)


REASON FOR MY SLOW PROGRESS (apart from being otherwise occupied)...

To resolve (one or MORE of) these issues the wrong way could be expensive. I have read
enough posts about lucky people spending thousands of dollars - yet still have the same
problem - that I have been wanting to get a better FOCUS (ie info or advice) on the
REAL/ACTUAL problem before committing to "Go-time".


Now, to last Saturday...

First trip: Weather temp 37o C. Car runs normal and fine; water temp is good. Parked
20 mins. Re-start; off we go.

Second trip: Weather temp 39o C. Car runs fine; temp good. Parked 60 mins (good shade).
Won't re-start. After several re-tries about 30mins apart - 2 hours later
car starts.

Third trip: Weather temp 39o C. Car runs fine; water temp is good. Conks out half-way
home (after about 1 km). Won't re-start. I move into zombie mode - wait 20
to 30 mins before re-try.

While waiting to re-start, one of the local lads came flying past on an (mi
e-scooter. He stopped to offer assistance. He said that he has experience
with Commodores and VT's. I mentioned to him about the "cold-water-on-the-CAS"
trick for a re-start. He's never heard of it. (And I've never tried it.)
Since I had about a cupful of ice-water in my freezer bag I discussed trying
it. "Brad" (might not be his real name) thinks it should go on the "harmonic
balancer". (?) Anyway I slowly pour the cupful of chilled water on the CAS.
Before I know it, "Brad" (might not be his real name) pours his warmish
drinking water on the "harmonic balancer" (actually the belt tensioner!). I
try re-start. (Belt squealed a bit.) Nuttin'! "Brad" (might not be his real
name) suggests holding accelerator to the floor. (I don't want to because
the Manual says "don't", but what have I got to lose? I'll be dead soon; it's
39oC. "Sun temp" is actually about 56oC !) No start. Due to the excessive
cranking my past experience tells me it will be another 40mins before I can
try again.

"Brad" (might not be his real name) comes to the driver's window and mentions
about the "immobilizer" being a problem sometimes. (The sun's getting to me.
"What's he on about?") He is suggesting re-locking the doors, then unlocking
them again, and trying for another re-start. From past experience, I know
this won't work (ie trying another re-start "immediately", like that) but what
have I got to lose? I've already got a wet pulley-tensioner!

To satisfy Brad's (might not be his real name) insistance in the diagnosis I
alight the vehicle, lock the doors then re-open them. I get back in to give
it a go. STARTS!! What?! WOW! I mean W O W !!!! It powered to life in
a flash, even after all that cranking (and fuel-flooding?) that I did just
40-ish seconds ago. W O W !!!

I thanked "Brad" (a lot), then left to get home quickly - before another
"stalling" episode.

Fourth trip: I made it home (1km), no problemo.


NOW, LET'S TALK ABOUT THIS A LITTLE...

Either "Brad" is correct and the Immobilizer/Keypad is part of the malfunctioning - or something
else just happened.

1. The key was replaced about 5-ish years ago - so it could be the key's battery? Could be
something else in the ignition connectivity?

...OR...

2. The chilled water on the CAS had a delayed effect (ie the "chill" took time to travel along
the sensor stem to sensor tip inside the engine?


REMEMBER, this episode that I bring to you might not be - wholly - about the "stalling", but
ONLY about the "re-starting".

So here is my request to each of you. Apart from any issue that might really be a solution to
the stalling, do you think the RE-START issue could be:

A. the chilled water on the CAS that was the rapid solution (no pun intended)?

OR

B. the immobilizer/key/battery was/is the whole (or major part) of this problem of failing
to re-start?

OR

C. something else?


While I'm happy to entertain valid ideas on the stalling (but I've read many, MANY similar
stories anyway) I guess I'm wanting this immediate post/reply to be focussed on the amazing
RE-START, as it happened. What do you think solved the re-start so rapidly? Chilled water?
Key? Other?


[FYI: On the stalling, I will be looking further at the 3 options mentioned earlier. Clearly,
the outcome of your vote/discussion on the key/CAS thing might help drive me in one direction
or another. (Pun intended). And, for the time being, I am thinking they are the only options
that need to be considered.]


So, please, feel free to jump in with your vote/comment on the key/chilled water thing. (Even
a useful opinion will be appreciated.)


Regards,
boombaby (might not be my real name)

 

[lout]

too long story
zoned out halfway
please clarify if it cranks normally or slowly when it "wont start"
until i got sick of reading, it sounds like classic crank angle sensor

 

[Fu Manchu]

Hello, Any/Every!


I'm gettin' there. Patience!

The fundamental issue is that I have been trying to nail-down a Commodo VT V6 Ecotech
"stalling" issue. (We love those don't we!)

I will be asking each of you to give an opinion - BUT - rather than getting 10/20/50
people providing 10/20/50 different "things" I will be happy if 1/2/3 different
diagnoses become the serious contenders. (I hope I explained that well enough.) Later,
I will explain exactly "WHY" I'm asking for your advice/help this way, now.

Some Background...

On various occasions, in other posts, I have mentioned a couple of my VT issues. However,
since I will be making this as the main/direct thread about them, I will briefly describe
the problem(s) and my diagnostics so far.

Main theme... "Sudden stalling, after which VT fails to start immediately (ie WILL
re-start after a waiting period)". This is not a consistent condition on every drive;
it occurs out-of-the-blue, sometimes weeks/months apart.

In recent months I have been dragged off into bundles of other critical activities so I
have not been able to attend to this enough. (Fortunately, I have not had to rely on the
VT for many trips.) However, on last Saturday I had to do several short hops, but on the
2nd hop it failed to start after being parked for about an hour; and on the 3rd hop it
stalled on the way back home. (I'll get back to those moments, shortly. The rather odd
outcome from those events became the motivation to seek your advice/input now.)

Quick background/ on my efforts so far.
1. 2016, bought VT with 161k's for a low price.
2. Always ran well - but I never maintained it. (Save the criticism; I know it's slack!
This is my first Fuel Injection - and I thought it would be much easier to repair if
problems arose. Turns out DFI works better if it is maintained constantly - using
bucketloads of money. Tonnes and tonnes of money. Yes; that's a very weak argument
BUT it's the only one I've got!)
3. Recently, at 175k's, the "stalling" issue raised it's ugly head. And it is pretty
ugly. DFI (and the GMH design) is my new learning curve.
4. Cleaned MAF; replaced air filter, oil, alternator, battery. Purchased Vident scanner
which is showing the vehicle is running just within limits, but on the "rich" side.
At the moment that (alone) does not prompt me to a solution.
5. After checking all sensor activity and clearing codes the VT seems to settle on code
?-47-? "missing 18x signal". [I know that COULD be pointing directly at the CAS, but
I have also read that it could be a sign of failing/failed power packs or connections
(etc) too. From memory, I think that's right.]

However, I DON'T want you to focus too much on that stuff at the moment; I only want you
to keep it in mind when I tell you about last Saturday.

So, in terms of ME narrowing down the "stalling" issues, here's where I'm at:
1. It could be the CAS.
2. It could be the fuel filter and/or fuel pump.
3. It could be one (or more) of the DFI module or coil packs. [Someone told me
that after the car stalls feel each of the 3 coil packs with the back of fingers
because it can reveal that one is excessively hot - and failing/failed. (Well,
I have one hot, one intermediate, and one OK.)


REASON FOR MY SLOW PROGRESS (apart from being otherwise occupied)...

To resolve (one or MORE of) these issues the wrong way could be expensive. I have read
enough posts about lucky people spending thousands of dollars - yet still have the same
problem - that I have been wanting to get a better FOCUS (ie info or advice) on the
REAL/ACTUAL problem before committing to "Go-time".


Now, to last Saturday...

First trip: Weather temp 37o C. Car runs normal and fine; water temp is good. Parked
20 mins. Re-start; off we go.

Second trip: Weather temp 39o C. Car runs fine; temp good. Parked 60 mins (good shade).
Won't re-start. After several re-tries about 30mins apart - 2 hours later
car starts.

Third trip: Weather temp 39o C. Car runs fine; water temp is good. Conks out half-way
home (after about 1 km). Won't re-start. I move into zombie mode - wait 20
to 30 mins before re-try.

While waiting to re-start, one of the local lads came flying past on an (mi
e-scooter. He stopped to offer assistance. He said that he has experience
with Commodores and VT's. I mentioned to him about the "cold-water-on-the-CAS"
trick for a re-start. He's never heard of it. (And I've never tried it.)
Since I had about a cupful of ice-water in my freezer bag I discussed trying
it. "Brad" (might not be his real name) thinks it should go on the "harmonic
balancer". (?) Anyway I slowly pour the cupful of chilled water on the CAS.
Before I know it, "Brad" (might not be his real name) pours his warmish
drinking water on the "harmonic balancer" (actually the belt tensioner!). I
try re-start. (Belt squealed a bit.) Nuttin'! "Brad" (might not be his real
name) suggests holding accelerator to the floor. (I don't want to because
the Manual says "don't", but what have I got to lose? I'll be dead soon; it's
39oC. "Sun temp" is actually about 56oC !) No start. Due to the excessive
cranking my past experience tells me it will be another 40mins before I can
try again.

"Brad" (might not be his real name) comes to the driver's window and mentions
about the "immobilizer" being a problem sometimes. (The sun's getting to me.
"What's he on about?") He is suggesting re-locking the doors, then unlocking
them again, and trying for another re-start. From past experience, I know
this won't work (ie trying another re-start "immediately", like that) but what
have I got to lose? I've already got a wet pulley-tensioner!

To satisfy Brad's (might not be his real name) insistance in the diagnosis I
alight the vehicle, lock the doors then re-open them. I get back in to give
it a go. STARTS!! What?! WOW! I mean W O W !!!! It powered to life in
a flash, even after all that cranking (and fuel-flooding?) that I did just
40-ish seconds ago. W O W !!!

I thanked "Brad" (a lot), then left to get home quickly - before another
"stalling" episode.

Fourth trip: I made it home (1km), no problemo.


NOW, LET'S TALK ABOUT THIS A LITTLE...

Either "Brad" is correct and the Immobilizer/Keypad is part of the malfunctioning - or something
else just happened.

1. The key was replaced about 5-ish years ago - so it could be the key's battery? Could be
something else in the ignition connectivity?

...OR...

2. The chilled water on the CAS had a delayed effect (ie the "chill" took time to travel along
the sensor stem to sensor tip inside the engine?


REMEMBER, this episode that I bring to you might not be - wholly - about the "stalling", but
ONLY about the "re-starting".

So here is my request to each of you. Apart from any issue that might really be a solution to
the stalling, do you think the RE-START issue could be:

A. the chilled water on the CAS that was the rapid solution (no pun intended)?

OR

B. the immobilizer/key/battery was/is the whole (or major part) of this problem of failing
to re-start?

OR

C. something else?


While I'm happy to entertain valid ideas on the stalling (but I've read many, MANY similar
stories anyway) I guess I'm wanting this immediate post/reply to be focussed on the amazing
RE-START, as it happened. What do you think solved the re-start so rapidly? Chilled water?
Key? Other?


[FYI: On the stalling, I will be looking further at the 3 options mentioned earlier. Clearly,
the outcome of your vote/discussion on the key/CAS thing might help drive me in one direction
or another. (Pun intended). And, for the time being, I am thinking they are the only options
that need to be considered.]


So, please, feel free to jump in with your vote/comment on the key/chilled water thing. (Even
a useful opinion will be appreciated.)


Regards,
boombaby (might not be my real name)

I’d bet it’s the CAS. However if you don’t want to parts swap, then you need data. Not just the data so far but wave form data that you can use to find hidden (compared to the methods so far) faults.
Give Romanos a call (in Wangara.) There’s a guy there that will follow a methodical data based fault finding diagnostics process. Has good form with Commodores.

 

[boombaby]

too long story
zoned out halfway
please clarify if it cranks normally or slowly when it "wont start"
until i got sick of reading, it sounds like classic crank angle sensor

Hi, lout!


Yeah, I know what you mean. I fell asleep twice, writing it.

I appreciate that advice. I also suspect (probably about 80%
level) that it is the CAS doing the stalling, but I think there's
more going on too. That's why I mentioned the ignition and fuel
filter/pump - for clarity (not boredom). When I wrote it on my
computer here, then cut-and-pasted to the forum, it lost all it's
formatting/layout - which made it hard to read too. Sorry about
that. With the formatting it's a bit easier.


lout, I wouldn't mind if you could tackle the last part for me.
See, the answer is not "CAS"; the answer should be either, "Key"
or "Chilled Water". It's really about the re-start that happened.
And I suspect YOU would be one who might know exactly which is
the right answer, given your kind of knowledge/experience. (That's
from my reading in these forums.)


If you read further towards the end, from the part that starts "Now
to last Saturday..." you will understand WHY I need to try and get
the answer (as just mentioned). THAT is going to give me a great
bit of clarity.



I really want the answer as sought above, but in answer to YOUR
question to me...

After a stall, the car turns over pretty-much normally. However
I can tell you too, that sometimes (say 50%?) it seems as if the
first rotation or two it's about to start, then it seems to turn
just a smidgen quicker. (It's a bit hard to pick, unless I
concentrate on it.) When I detect THAT I can tell immediately
that it's all over, red rover. Sit and wait! (At that point, if
I try to re-start it, it will to take a longer wait-time before it
WILL start. And it seems worse on hot days, but not always.)

Anyway, lout, if you could read that last bit and give your advice
it would be much appreciated. (Sorry about the lost formatting. I'll
try to fix it later.)



The only thing necessary for evil to triumph in the world is that good
men do nothing. (Ouch!)

Only joking!!


Kind Regards,
boombaby

 

[boombaby]

I’d bet it’s the CAS. However if you don’t want to parts swap, then you need data. Not just the data so far but wave form data that you can use to find hidden (compared to the methods so far) faults.
Give Romanos a call (in Wangara.) There’s a guy there that will follow a methodical data based fault finding diagnostics process. Has good form with Commodores.

Thanks, Fu Manchu!

As I said to lout, I am leaning towards that too. My plan is gelling
towards CAS replacement. It will be a little beyond me, I suspect.
My son uses a great Ultra Tune further south. I live near Armadale.
They were also recommended to me by someone else who knows
them well.

(I am DEFINITELY NOT discounting your advice so far. If I can do
something with it I will. It's a long stretch to Wangara, especially
when I - sometimes - can't get beyond 2 kms.)

[I agree with you about the "data" bit. I picked up an oscilloscope
but I have not had a chance to get into that yet.]

Fu, in my previous post would you mind reading from the part that
starts, "Now to last Saturday...". The answer should be "Key" or
"Chilled Water". You will probably know exactly which one. The
answer is important to my understanding and decision-making.


Thanks, so far.
boombaby

 

[Fu Manchu]

Rob’s skills are not in every workshop.

 

[Fu Manchu]

You can get freeze spray from the chemist or Jaycar. Get a can and have it with you, get the car to stall or what ever it’s doing, spray the CAS there in the front (as best you can) and I bet the car starts again.

 

[lout]

i read the second part of the story, had to stop for coffee and sandwiches half way
leads me even more to crank angle sensor
anything takes a while to cool down
to prove further
jack up front of car and place on stands
pinch your ladies hairdrier, or if you are woke, use your own
heat the crap out of the crank sensor, located where wiring runs behind harmonic balancer
so hot you cannot hold onto it
then see if car starts, whilst watching mode immobilizer light
if car starts, not hot enough or crank sensor is ok
if doesnt start and mode stops flashing then crank sensor is faulty
if mode light keeps flashing the immobilizer issue

 

[Immortality]

If you have a scanner have that in the car and when it stalls scan it and see what it says.

You may have more than one thing going on.

As far as I'm aware, once the engine has started the immobilizer can't kill the engine. When you go to start the car the PCM is looking for a signal from the BCM/key, no signal, no start. Now I have had issues with "new" keys (non genuine) where occasionally the key seems to loose contact/sync with the BCM (key works on a rolling code I believe) and this might cause a no start condition or the remote lock/unlock function not to work. Clean the contact strip around the ignition switch and the little steel stub on the end of the key. Sometimes just simply locking/locking the car will reset these functions and everything is happy as Larry again.

Now I know a guy who had the same problem and couldn't figure it out, a mechanic at work looked it over and tested it and eventually found there was oil in the CAS plug that was randomly causing issues. Remove all the plugs for the Crank angle sensor, Cam sensor and DFI and make sure all are clean and no corrosion or contaminants are present.

Electrical components don't last forever. The DFI and coils don't have an indefinite life span. Consider buying a new/spare set.

One thing often overlooked is the cam sensor. This sensor shares a power and earth supply with the crank sensor. I know of one case (and I'm sure there are plenty more) where a faulty cam sensor effected the power supply to the crank sensor enough to cause a bad 18x/3x signal to the DFI and PCM causing a no run situation (the person who found it had the fancy testing equipment including oscilloscope to accurately measure sensor performance).

Unfortunately the ignition system does seem to be a bit of an Achilles heal on these engines. Having said that (touch wood), our VX is still on the original DFI module, cam and crank sensors but has had 2 sets of new coils (290xxx km).

I do agree with the others though, on the face of it, this does sound like the typical CAS sensor fault.

I also keep sets of DFI modules and coils in the garage (I've had multiple V6 cars) plus a brand new CAS sensor and have not had to replace these. I don't like Murphy!

 

[Lex]

I couldn't be stuffed reading all the posts.

Where are the parts coming from?

That couyld be a problem replacing parts that have seen better days with crap parts?