What is this

[Cyclops389]

I was changing my O2 sensor tonight and found this connector stuck in that area below the turbo.

I just got the Grand National and am new to the cars but this looks kind of important.

Thanks in advance

 

[gnmaster2004]

Looks like the oil pressure switch connector

 

[turbo billy]

It is

Sent from my S55 using Tapatalk

 

[Cyclops389]

That should probably be plugged up right? Without removing the turbo I couldn't see where it goes.

 

[ScottHeidinger]

That connects to the idiot light on your dash. The sensor was probably removed to install a oil pressure gauge sending unit. As long as you have a working oil pressure gauge you can wrap that up with electric tape out of the way. Don't leave it where it will melt and short out. If you don't have a oil pressure gauge then find the switch that is on the manifold going to the oil feed line on the turbo and plug it back in. A idiot light is better than nothing.


Sent from my iPhone using Tapatalk

 

[Cyclops389]

Okay guys here's another for you lol. I was looking for the oil pressure switch (which I still didn't locate) and I found this vacuum block sitting on the passenger side of the motor laying beside the valve cover on the block.

 

[Cyclops389]

That connects to the idiot light on your dash. The sensor was probably removed to install a oil pressure gauge sending unit. As long as you have a working oil pressure gauge you can wrap that up with electric tape out of the way. Don't leave it where it will melt and short out. If you don't have a oil pressure gauge then find the switch that is on the manifold going to the oil feed line on the turbo and plug it back in. A idiot light is better than nothing.


Sent from my iPhone using Tapatalk

Thanks I do have a working gauge.

 

[ScottHeidinger]

That's your stock boost control solenoid for factory waste gate control. Left connected so you don't get a ses light. I assume you're running a aftermarket boost controller


Sent from my iPhone using Tapatalk

 

[Cyclops389]

That's your stock boost control solenoid for factory waste gate control. Left connected so you don't get a ses light. I assume you're running a aftermarket boost controller


Sent from my iPhone using Tapatalk

Don't have a clue. Just bought the car a month ago and I didn't get it from the owner so I'm not sure. I'm working on contacting him now for more info but it hasn't been easy.

I'm new to turbo Buicks and I know the guy did some upgrades but I'm having to find them myself.

 

[Cyclops389]

It has a scanmaster.

It has a chip set

There's a three way switch in the center console (I believe this is a fan control switch) the car is down right now from a burnt fan motor because I didn't know that was the switch. It was running all the time.

 

[michael evans]

There are two vacuum lines to follow that control your boost. One comes out of your turbo's outlet the other is on the actuator that controls the waste gate.
Follow them both and tell us where they end up.

 

[ScottHeidinger]

Look at the vacuum looking line on the turbo. It should go from the outside of the housing to a Y fitting with something attached to control the boost. Could be a manual bleed off valve or a RJC style boost control devise that keeps the wastegate completely shut until you reach the boost level that it's been set for and then pops open. Then again after 30 years and likely many mods it could be set up completely different.
Please be careful until you know what everything is and why it is set up the way it is. I've seen plenty of people buy these cars and not knowing or understanding "how it works" they think they are fixing something only to later figure out why something was not connected after blowing head gaskets because they didn't understand "how it works"
My guess is that someone before you has installed a aftermarket boost controller but he may have done so because the stock solenoid was broken or could have just wanted to increase the boost. If it broken and you put it back together in stock configuration you might hit 25 PSI of boost and blow the head gaskets before you know what happened. I would try to get as much information about what has been done to the car and why before you change anything.


Sent from my iPhone using Tapatalk

 

[Cyclops389]

Look at the vacuum looking line on the turbo. It should go from the outside of the housing to a Y fitting with something attached to control the boost. Could be a manual bleed off valve or a RJC style boost control devise that keeps the wastegate completely shut until you reach the boost level that it's been set for and then pops open. Then again after 30 years and likely many mods it could be set up completely different.
Please be careful until you know what everything is and why it is set up the way it is. I've seen plenty of people buy these cars and not knowing or understanding "how it works" they think they are fixing something only to later figure out why something was not connected after blowing head gaskets because they didn't understand "how it works"
My guess is that someone before you has installed a aftermarket boost controller but he may have done so because the stock solenoid was broken or could have just wanted to increase the boost. If it broken and you put it back together in stock configuration you might hit 25 PSI of boost and blow the head gaskets before you know what happened. I would try to get as much information about what has been done to the car and why before you change anything.

That's why I'm on here. I haven't even got on the car hard yet. I have a whole set of chips with it but wanted to learn more about it before swapping them out. I appreciate all the help as there aren't and turbo Buick guys in my area to ask about it.

 

[Cyclops389]

There are two vacuum lines to follow that control your boost. One comes out of your turbo's outlet the other is on the actuator that controls the waste gate.
Follow them both and tell us where they end up.

They both run under the fan motor on the passenger side and into the cab. I looked to see where they ended up in the cab but didn't see them from that side.

The one that comes from the actuator has a T in the line and has another vacuum that runs to the driver side and enters the cab.

 

[michael evans]

In any case if you don't want to install a manual boost gauge in the cockpit where you can see it. learn how to use the scan master to read you boost. It might save you from having to tear your engine down like I did.

I have a manual gauge where I can see it.

If you need to take a 7mm to remove the three screws that hold the panel in place under the glove box to see the firewall.

 

[Cyclops389]

In any case if you don't want to install a manual boost gauge in the cockpit where you can see it. learn how to use the scan master to read you boost. It might save you from having to tear your engine down like I did.

I have a manual gauge where I can see it.

I don't mind adding the controller but I still need to learn a little more about the boost


Sent from my iPhone using Tapatalk

 

[michael evans]

I don't mind adding the controller but I still need to learn a little more about the boost


I need to learn more about it also. I took out all the factory electronics ( they were to slow for me ) and changed to XFI. That way I only have to learn it once.

It is different ballgame

 

[Cyclops389]

I want to get a feel for it and learn what all sin before I start adding to it. It's runs pretty good now once I can get the fans going again.


Sent from my iPhone using Tapatalk

 

[TurboTGuy]

Okay guys here's another for you lol. I was looking for the oil pressure switch (which I still didn't locate) and I found this vacuum block sitting on the passenger side of the motor laying beside the valve cover on the block.

Hang on to that boost solenoid (pictured) until you are absolutely sure what's controlling the boost on your new purchase.

Stock parts removed and just tossed about in the engine bay, something to give pause........

 

[Cyclops389]

Hang on to that boost solenoid (pictured) until you are absolutely sure what's controlling the boost on your new purchase.

Stock parts removed and just tossed about in the engine bay, something to give pause........

For sure. Thanks for all the help guys. I know I will have more coming soon


Sent from my iPhone using Tapatalk