VY Stalls under Deceleration only

[fugly59]

This was exactly the post that I needed answered. Until the slanging match started
I have a VY V6 with pretty much exactly the same problem.
The main difference here is that it only appeared after I replaced the inlet manifold gasket.
I have temporarily 'cured' the problem by disconnecting the MAF sensor. It runs absolutely perfectly except for 'maybe' that it idles a fraction higher. It also has the obligatory 'Check Engine' sign on the dash.
I actually purchased a brand new MAF sensor thinking that this would fix the problem. Unfortunately, it runs exactly the same with the new unit connected. I am only running the vehicle to & from work at the moment (20 minutes each way) as I don't want to drive it too far without it running properly.
I have also removed the throttle body assembly again. Cleaned it again. Took out the idle control unit. It was a bit dirty so I thought I'd found the culprit. Both hoses were connected onto the bottom. Still no difference. Looking at the tacho, it seems to stall when the transmission changes but only while coasting down a hill or into a corner.
I am thinking that maybe 1 of the 3 hoses connected to the end of the 'plenum' (is that correct?) may be the culprit. I am confident with the brake booster hose but not the other 2. I don't even know what they do.
If anyone has any answers or suggestions, I'd like to hear them.
Thank You

 

[Trevor loves holden.]

This was exactly the post that I needed answered. Until the slanging match started
I have a VY V6 with pretty much exactly the same problem.
The main difference here is that it only appeared after I replaced the inlet manifold gasket.
I have temporarily 'cured' the problem by disconnecting the MAF sensor. It runs absolutely perfectly except for 'maybe' that it idles a fraction higher. It also has the obligatory 'Check Engine' sign on the dash.
I actually purchased a brand new MAF sensor thinking that this would fix the problem. Unfortunately, it runs exactly the same with the new unit connected. I am only running the vehicle to & from work at the moment (20 minutes each way) as I don't want to drive it too far without it running properly.
I have also removed the throttle body assembly again. Cleaned it again. Took out the idle control unit. It was a bit dirty so I thought I'd found the culprit. Both hoses were connected onto the bottom. Still no difference. Looking at the tacho, it seems to stall when the transmission changes but only while coasting down a hill or into a corner.
I am thinking that maybe 1 of the 3 hoses connected to the end of the 'plenum' (is that correct?) may be the culprit. I am confident with the brake booster hose but not the other 2. I don't even know what they do.
If anyone has any answers or suggestions, I'd like to hear them.
Thank You

Maybe scan the fault codes and go from there, if it only started after you removed the intake one must ask what didn't you do correct.

Could be anything, most probably your IAC valve not allowing air in on low revs to pick up your idle. Try shifting into rev then back to park you should see your tacho go up then down if its not then buy a new IAC.

 

[Utel67]

You do have the MAF on the right way, arrow facing the throttle body.

 

[fugly59]

Maybe scan the fault codes and go from there, if it only started after you removed the intake one must ask what didn't you do correct.

Could be anything, most probably your IAC valve not allowing air in on low revs to pick up your idle. Try shifting into rev then back to park you should see your tacho go up then down if its not then buy a new IAC.

Thanks for the reply.
Trust me, my ONLY question is what didn't I do correctly?

The picture you have is brilliant. The fuel pressure regulator hose is what I am going to approach first. It was pretty hard & I probably should have replaced it when I did the job but I didn't have that size.
I did read the codes before I replaced the MAF sensor but it was all clear, but seeing as it runs fine without it connected, I thought that it had to be the problem. I am at least hoping that, because it runs fine without the MAF sensor, whatever I have done wrong is minor.
Will let you know how I go.
Thanks again.

 

[fugly59]

You do have the MAF on the right way, arrow facing the throttle body.

Thanks for the reply.
I just double checked. I'm questioning everything.
I actually left the original MAF sensor in position. I just removed the hose.
The new unit is in the correct orientation.
Thanks anyway

 

[Trevor loves holden.]

Sounds like fuel pressure is the problem, didn't put the valve in the wrong direction only flows one way.

 

[fugly59]

Sounds like fuel pressure is the problem, didn't put the valve in the wrong direction only flows one way.

Thank You.
Excuse my ignorance but are you talking about the regulator valve on the fuel rail?
I never removed that. The only thing that affected it was the hose to the back of the Plenum that I will be looking at tomorrow.
If not, which valve do you mean?
Thanks again.

 

[Trevor loves holden.]

Thank You.
Excuse my ignorance but are you talking about the regulator valve on the fuel rail?
I never removed that. The only thing that affected it was the hose to the back of the Plenum that I will be looking at tomorrow.
If not, which valve do you mean?
Thanks again.

Discard sorry I was thinking of something else.

 

[fugly59]

I purchased a new IAC & installed it. No difference.
Hoses have been replaced at the back of the plenum. No difference.
Disconnect the MAF sensor again. Runs perfectly!!!!! I mean absolutely no sign of any problem. I took it on the expressway for a 30km run and it runs like a dream. Does anyone have any idea why it works fine without it connected?
Does anybody know if I can short the MAF sensor so it doesn't come up with any 'Check Engine' on the dash. Or should I be searching the whole throttle body arrangement for a problem?
I've had this car for 5 years, up until now, I've really enjoyed it. Maybe it's time for me to spend some money and take it to a mechanic who knows more about it than I do. Shouldn't be difficult.
Thanks anyway guys.
If I ever find out what I have done wrong, I will let you know.
Cheers

Maybe scan the fault codes and go from there, if it only started after you removed the intake one must ask what didn't you do correct.

Could be anything, most probably your IAC valve not allowing air in on low revs to pick up your idle. Try shifting into rev then back to park you should see your tacho go up then down if its not then buy a new IAC.

 

[Utel67]

Try adjusting your throttle stop screw a little bit at a time, if you have a scan tool to check IAC steps it should be set around 30 steps when the engine is at running temp.