What did you do to your Volvo today?

[bmdubya1198]

You checked the wastegate with the pressure setting, correct? Most Mityvac models only do vacuum.

I believe the GLT should be set to 2 PSI, but I'd have to confirm that.

[99commutervolvos70]

You checked the wastegate with the pressure setting, correct? Most Mityvac models only do vacuum.

I believe the GLT should be set to 2 PSI, but I'd have to confirm that.

Yes, the mightyvac I used only has a vacuum gauge on it. I basically wanted to check if the diaphragm was leaking, which it is not. When i applied pressure to the wastegate actuator it moved and held.

This issue just happend recently, so I am thinking it may not be a setting issue. I haven't touched anything turbo related in the 60k that I have had it. The car has over 277k on it. The wastegate actuator DOES look to be very shiny and "new" looking (doesn't look like it has 277k on it), would love to get one of those deals from Ipd and check the base setting.

For now, I think I will just hook the wastegate actuator directly to the port on the turbo and see if it reaches the 2psi setting. I installed a new pierburg TCV and a Bosch Boost sensor.

I drive this car every day a minimum of 80 miles a day, so I will eventually get to the bottom of it

[bmdubya1198]

Probably something simple, but a pain to pinpoint. That's usually the case with boost issues!

[99commutervolvos70]

Probably something simple, but a pain to pinpoint. That's usually the case with boost issues!

Well I unplugged my TCV electrically, which should directly link the red and yellow vacuum hoses. Now I get progressive boost to about 3psi with no spikes at all. So either my new TVS is defective or my original one was defective and I didn't notice it because my wastegate actuator is not adjusted properly...

So I will have to do some searching to see what the spec is for the LPT turbo. Perhaps someone previously replaced the wastegate actuator that was meant for a T5 that is set at 4 psi?

[abscate]

Is that right? Is default no power setting on a TCV connecting full boost to wastegate?

I though it dumped to blue/ Snorkel

[99commutervolvos70]

Is that right? Is default no power setting on a TCV connecting full boost to wastegate?

I though it dumped to blue/ Snorkel

I believe when it is disconnected electrically, it defaults to full pressure to the wastgate (same as connecting the wastegate actuator directly to the turbo), which will keep it closed until it reaches whatever the wastegate rod was initially set at.
It is slower to build boost with it bypassed, but it does not overboost.

It did set a CEL on my 2nd trip P0234. Tomorrow I plan on checking the wastegate setting with a pressure gauge teed into my mightyvac. I have a feeling it will be around 3 to 4 psi. I guess it is supposed to be around 1.8 psi for my LPT.

It dumps when it is energized which keeps the wastegate shut, which increases boost.
I've been studying this system for a few days now

Moderators can move this if it is posted in the wrong area.

[bmdubya1198]

The TCV stays open when it is not connected to the ECU. The TCV is closed by the ECU grounding the constant voltage (I believe), allowing boost to build. 100% duty cycle is full boost, 0% is wastegate pressure.

LPT WG setting may be 1.8 PSI now that you mention it. I had a chart somewhere...

[erikv11]

I rarely post any pics of my cars - here's one!

The V70 is 427 black, here it is the day after finishing a 2,000 mile round trip over the December holiday. I like the 427 color, it edges a bit toward gray. The 850 R in the background is standard 426 Black, you can see the color difference somewhat here.

427 black V70 and 426 black 850

[abscate]

Are those the Perfo or Columba wheels on the V70? Paint looks incredible on a decades oldcar(s)

[raivis_rsn]

Columba