All three pipes are connected to the TCV, only the end that was connected to the recirc valve is not as Volvo intended.
Alex.
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All three pipes are connected to the TCV, only the end that was connected to the recirc valve is not as Volvo intended.
Alex.
The recirc valve needs boost pressure to operate, so a hose from TCV to the recirc valve would stop the TCV bleeding off enough pressure (therefore opening the wastegate too early) & probably impair the operation of the recirc
If the same hose is capped off, it will have the same effect - TCV is unable to bleed
I have just had a quick look in the works car park and I think we may have found the problem...
The pipe that is capped and was connected to the recirc valve, is also connected to the bottom of the TCV!
So if I connect the correct pipe to the bottom of the TCV, I should (hopefully) have available boost.
Little things are starting to make sense, as these pipes must have been wrong since I rebuilt the top end 3 years ago. I thought that there was decent power after the rebuild, but that may have been the weeks driving the wife's old 1.6 megane and a refreshed engine. There was more turbo noise, the chirping described earlier in this thread, which would have been the dump valve not working.
I am disappointed in myself for getting something so simple/important, so wrong.
I will investigate and correct these pipes this afternoon and then test with a 'quick' trip to Suffolk/Norfolk...
Alex.
Me7 tcv...
Metal port connects to the compressor housing.
Opposite port connects to the inlet pipe.
Port at 90 degrees connects to the wastegate actuator.
Recirc is connected to the right of the inlet manifold.
nothing to be embarrassed I am just learning also. Hopefully that is your easy fix. Yes that TCV outlet needs to go either to fresh air or to the maf/turbo pipe, preferably the latter so you don't have another hole to plug
Got to ask - the hose that should go to the recirc valve, from the inlet manifold as martin mentions above, where does that go now? That is the one which needs to be capped
Not embarrassed, just disappointed with myself. Also not that I connected the wrong pipes, but that it has taken me THREE YEARS to get round to finding out what I did wrong!
The pipe from the inlet manifold is connected to wherever the pipe from the bottom of the TCV should be connected, so the MAF/turbo pipe... I intend to swap the capped pipe currently connected to the TCV, to the inlet manifold and the pipe currently connected to the inlet manifold, onto the TCV.
Alex.
I think we've finally got to the bottom of your problem.
Its the problem with diagnosis over the internet!
most of us would have taken one look at the car & new straight away but on the net you just have to assume everything is in its correct place.....
Almost...
Swapped the pipes over and there is more boost! Just not quite enough.
Torque is reporting 9psi, so that is better than before but there is still something not quite right.
I did hear some strange noises that could be a leak while under hard acceleration, so that is the next place to look. I can only assume that the boost before was not enough to cause the leak to erm, leak!
Alex.
Have you replaced your vac hose with new whilst swapping them around?
If they are old pipes they may have perished.
Also I'm not sure if running them incorrectly may damage the TCV/BCS, I'd definitely replace all the vacuum pipes and also consider getting a new BCS.
It should only run 10 psi as standard , so taking into account the fact that the torque app could be 10% out, you're about right.
A boost gauge would confirm it but sounds not far away as Stribo's comment
Unfortunately your mpg will be worse now but think of all that cash saved over the last few years!!
While torque could be 10% or more out, it was reading high before swapping the pipes.
At the same time that the dyno man read 4psi, torque was reading 6psi.
She does not feel as quick or sprightly as before, or even the other day when disconnecting the wastegate.
Alex.
wind the wastegate arm in a couple of turns :)
yep, shorten the arm a bit.
Torque app is stupidly out on my R.