Stock boost controller won't hold vacuum

mblum

New Member
Joined
May 23, 2021
I'm in the middle of getting my recently acquired 86 GN back on the road and today I as testing everything in the vacuum circuits with my Mighty Vac and finding more leaking components that components that hold vacuum it seems. When applying vacuum to the nipple that the vacuum hose attaches the OEM controller (mounts to the passember side valve cover ) will not hold vacuum. I'm assuming this is not normal. I've been searching Buick vendor websites and cannot find a replacement, not sure if I'm not looking in the correct areas of the website or they are just not available.

What's my best option here? I'm new to the TR and am still trying to learn.
 

TType85

Well-Known Member
Joined
May 25, 2001
I don't know if you are having a problem with your solenoid but hopefully it is good because they have been discontinued for a long time and I have seen them go for $250+ on ebay.

I would try it and see how the car runs. If the lines look good and it's not throwing a code send it.
 

mblum

New Member
Joined
May 23, 2021
Yes, it's the solenoid. Looks like this guy

When applying vacuum to the port the vacuum hose attaches I loose about 2.5 inches of vacuum per second. For example if I pump my Mighty Vac to 20 in it will be back to 0 in about 7-8 seconds. The didn't run well when I took possession of it, it hasn't been driven in about 13 years. I'm working through a long list of tasks to hopefully get it back up and going. Currently I'm chaining all gaskets (minus the head gaskets and rear main seal) on the engine as it was leaking oil everywhere. Changing valve springs, timing set, adding a hot wire kit, new fuel pump ect.

Before I started this work the car did run, just not well. I could only achieve 12 inches of vacuum at hot idle. I have found numerous vacuum leaks while testing and am testing all components a vacuum line attaches.

Could I use this solenoid as a replacement?
Its the AC Delco 214-1073 mentioned in Vortex Buicks
 

grass doctor

Dream Catcher
Joined
Sep 21, 2018
I have one that has a broken nipple ....covered up by the foam filter ...you can have cheap....
 

John Larkin

Sublime Master of Turbology
Joined
May 25, 2001
Your post made me curious so I hooked my mityvac up to mine. It pulls vacuum on both nipples and leaks down slowly, not as fast as yours. But it is not a vacuum holding mechanism as I see it. I think it functions like a pulsing valve to modulate the vacuum to the wastegate but its been a long time since I read about it.
 

grass doctor

Dream Catcher
Joined
Sep 21, 2018
it should seal IIRC...the boost solenoid...regulates boost pressure...the factory set up is progressive....it bleeds off boost until certain psi is reached, but it may not be fully sealed , never tested one and I am sure age is a factor....that is why most prefer the simple manual ones , where it is instant boost....
 

salvageV6

Daily Driver
Joined
May 25, 2001
I'd try it with pressure before I tried it with vacuum. Regulated shop air about 10-20 psi. in, and a pressure gauge on the other port, see if it leaks boost at all un-powered.
It also may work better (seal better) after cycling with 12 volts pulsed into it for a while to get the plunger moving.
Could be anything from dirt to a bugs home in there, as a last resort some solvent such as electronics cleaner or other quick drying stuff might help clean up the solenoid plunger.
 

grass doctor

Dream Catcher
Joined
Sep 21, 2018
I'd try it with pressure before I tried it with vacuum. Regulated shop air about 10-20 psi. in, and a pressure gauge on the other port, see if it leaks boost at all un-powered.
It also may work better (seal better) after cycling with 12 volts pulsed into it for a while to get the plunger moving.
Could be anything from dirt to a bugs home in there, as a last resort some solvent such as electronics cleaner or other quick drying stuff might help clean up the solenoid plunger.
or maybe a little silicone spray to condition...the seal after cleaning....
 

Lockman

OH, OK .......Now I get it
Joined
Dec 6, 2018
Yes, it's the solenoid. Looks like this guy

When applying vacuum to the port the vacuum hose attaches I loose about 2.5 inches of vacuum per second. For example if I pump my Mighty Vac to 20 in it will be back to 0 in about 7-8 seconds. The didn't run well when I took possession of it, it hasn't been driven in about 13 years. I'm working through a long list of tasks to hopefully get it back up and going. Currently I'm chaining all gaskets (minus the head gaskets and rear main seal) on the engine as it was leaking oil everywhere. Changing valve springs, timing set, adding a hot wire kit, new fuel pump ect.

Before I started this work the car did run, just not well. I could only achieve 12 inches of vacuum at hot idle. I have found numerous vacuum leaks while testing and am testing all components a vacuum line attaches.

Could I use this solenoid as a replacement?
Its the AC Delco 214-1073 mentioned in Vortex Buicks
Yeah.......The say that's for a truck diesel , but they will work on our Engines. It mounts differently than our OEM ones.
 

TurboTGuy

Gray Beard Member
Joined
Sep 24, 2010
Get a Hallman or similar manual boost controller and be done with it. No reason to try and revive and then trust a 30 plus year old part when several cheap and reliable alternatives are readily available.

Unless, of course, you're trying to keep everything show car style bone stock for some reason.
 

mblum

New Member
Joined
May 23, 2021
Thanks for the input guys, I'm just wanting to see what my options are. I may just go to a manual unit and call it done.
 

1986 Buick GX1

GX1 #001 [The One and Only]
Joined
Apr 24, 2015
Get a Hallman or similar manual boost controller and be done with it. No reason to try and revive and then trust a 30 plus year old part when several cheap and reliable alternatives are readily available.

Unless, of course, you're trying to keep everything show car style bone stock for some reason.
^^ X2
You can probably hide a manual boost controller for that stock look.
Some info on why an MBC spools quicker.


The Hallman knob style are a lot easier to adjust.
 
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