Turbo Dodge Forums banner

1 - 18 of 18 Posts

·
Premium Member
1986 GLH
Joined
·
13 Posts
Discussion Starter #1
I have a 1986 GLH. I am wanting to install a Boost gauge. I should be receiving my gauge today. I need some help on where to connect the vacuum line from the gauge. Any help/direction would be greatly appreciated.
 

·
Registered
Joined
·
2,061 Posts
If you don't want to pass through the firewall, you can tee into the MAP line that runs down to the logic module in the right kick panel. Then you just string the line from the kick panel to wherever your going to mount the gauge. Do yourself and others a favor and mount the gauge where you don't have to take your eyes off the road. Mounting it to the drivers side "A" (windshield) pillar is a good place. Hope you bought a mounting cup to go with the gauge purchase.
 

·
Premium Member
1986 GLH
Joined
·
13 Posts
Discussion Starter #3
If you don't want to pass through the firewall, you can tee into the MAP line that runs down to the logic module in the right kick panel. Then you just string the line from the kick panel to wherever your going to mount the gauge. Do yourself and others a favor and mount the gauge where you don't have to take your eyes off the road. Mounting it to the drivers side "A" (windshield) pillar is a good place. Hope you bought a mounting cup to go with the gauge purchase.
 

·
Premium Member
1986 GLH
Joined
·
13 Posts
Discussion Starter #4
Thank you for your reply. Got it. Is it just as good/accurate to "T" onto the MAP line in the kick panel as it is to take it through the fire wall into the engine compartment?
 

·
Registered
Joined
·
2,061 Posts
Thank you for your reply. Got it. Is it just as good/accurate to "T" onto the MAP line in the kick panel as it is to take it through the fire wall into the engine compartment?
Yes, but the line length will be a bit longer than running it through the firewall. The engine uses the MAP line, so if it's good enough for the engine ECU, it is good enough for your gauge. This way you don't have to deal with a plastic line in a hot engine bay.
 

·
Administrator
Joined
·
25,053 Posts
Just another opinion, ultimately it is your choice.

IMO the Map Sensor should have its own dedicated line with nothing else feeding from it.
(Although the factory tee'd the FPR and Map together.)
Map is the dominant sensor used by the controller for fuel and spark advance, any loss of vacuum to the Map will result in poor to extremely poor running conditions.

Again, IMO, if you want to tee into a vacuum source in the passenger compartment go underdash and tee into the main vacuum feed for the HVAC system, you would have to tee in before the check valve (which may be underhood).
The main vacuum source comes from the brake booster through the firewall.
Worse case scenario there should you lose vacuum would be that the HVAC system would go to default, which is defrost.

86 Turbo Vacuum.jpg HVAC 85-87 L-Body.jpg
 

·
Premium Member
1986 GLH
Joined
·
13 Posts
Discussion Starter #7
Thank you for the great information. I actually found the spare/capped vacuum line that is left on the factory vacuum harness. I went direct to that line and my gauge is working great. Decided to put the gauge in the left vent in my dash. I do not have A/C on my GLH so giving up the vent was no big deal.
 

Attachments

·
Registered
Joined
·
2,641 Posts
Welcome!!!

We like GLHT's, some even like Daytona's.

Daytona's are great donor cars to donate their innards.

Post up some pictures, description etc. when you get a chance.

This place is like a graveyard lately, we could use some new activity.

Thanks
Randy

I have a 1986 GLH. I am wanting to install a Boost gauge. I should be receiving my gauge today. I need some help on where to connect the vacuum line from the gauge. Any help/direction would be greatly appreciated.
 

·
Premium Member
Joined
·
1,214 Posts
Thank you for the great information. I actually found the spare/capped vacuum line that is left on the factory vacuum harness. I went direct to that line and my gauge is working great. Decided to put the gauge in the left vent in my dash. I do not have A/C on my GLH so giving up the vent was no big deal.
All good comments by others.

What you decided to do was exactly what that 4th port and plastic hose was originally allocated for.
Only some models had a factory boost gauge, and the ones that didn't (L-bodies for example) had the hose capped off.

The original vacuum block was part of a complete 4-hose harness.
It had the (4) long 1/8" dia. hoses welded in place.
Workers on the L-body assembly line capped of the 4th unused line.

NOTE:
Always check the 4th hose and make sure it's capped if not being used, or you'll have a vacuum leak.
The replacement vacuum blocks from Chrysler came with (4) short 1/8" dia. hoses welded to the front.
 

·
Premium Member
1986 GLH
Joined
·
13 Posts
Discussion Starter #10
Since I have installed a boost gauge I now have ordered a vacuum block and want to install with all new vacuum lines. I have done just a little reading on here on the vacuum blocks. I am a little concerned about getting into re-running the vacuum lines. Any input on this would be appreciated. I will take some pictures of my car and post soon. Thank you in advance.
 

·
Premium Member
Joined
·
1,214 Posts
Since I have installed a boost gauge I now have ordered a vacuum block and want to install with all new vacuum lines. I have done just a little reading on here on the vacuum blocks. I am a little concerned about getting into re-running the vacuum lines. Any input on this would be appreciated. I will take some pictures of my car and post soon. Thank you in advance.
A vacuum block is a very simple device with no mechanical moving parts.
It's a round, square or rectangular piece of metal or plastic that has two operational sides.
On one side is a port that gets vacuum from the intake manifold via a rubber hose.
Inside the block is an hollow chamber.
On the other side are several smaller ports that you attach your vacuum lines to.
Each port is identical and it doesn't matter which port is used for what device requiring vacuum.
The main thing is that there are no restrictions or turbulence inside the vacuum block.
If you were to look inside the inlet of the 1x4 (1 in, 4 out) round vacuum block used on Chrysler production cars, you would see clearly to the outlet ports with no restrictions.
 
  • Like
Reactions: Glhs60

·
Registered
Joined
·
2,641 Posts
The main thing I like about vacuum blocks is I can see where each hose goes.

The original vacuum harness is too convoluted ;)

Thanks
Randy
 

·
Premium Member
Joined
·
1,214 Posts
The main thing I like about vacuum blocks is I can see where each hose goes.

The original vacuum harness is too convoluted ;)

Thanks
Randy
Ok well then just remove the split loom on the original harness, buy 1/8" hoses in Neon Pink, Lime, Fuchsia, and Neon Blue......
.....and the girls will go Ooooooo! purty !!
And you've un-convoluted yourself!

😎😁😁
Sorry, I couldn't help it
 
  • Like
Reactions: Glhs60

·
Registered
Joined
·
2,061 Posts
A vacuum block is a very simple device with no mechanical moving parts.
It's a round, square or rectangular piece of metal or plastic that has two operational sides.
On one side is a port that gets vacuum from the valve cover via a rubber hose.
Inside the block is an hollow chamber....
I think you meant to say gets vacuum from intake manifold not valve cover right?
One mod I do many times on cars with 2 piece intakes is I drill and tap manifold for a vacuum/pressure port for a single very short line running to the fuel pressure regulator. Then run about 4-6" of silicone tubing instead of the factories 4-6' of tubing. The 4 into 1 barb will live a much longer life if you move it away from the heat source of the turbo. The factory could have really helped themselves and others by doing that one simple relocation.
 

·
Premium Member
1986 GLH
Joined
·
13 Posts
Discussion Starter #15
Anyone have a picture or example of what they have done? That would probably clear it up for me once I see it. And where is a good place to mount the new vacuum block?
 

·
Administrator
Joined
·
25,053 Posts
 

·
Premium Member
Joined
·
1,214 Posts
I think you meant to say gets vacuum from intake manifold not valve cover right?
One mod I do many times on cars with 2 piece intakes is I drill and tap manifold for a vacuum/pressure port for a single very short line running to the fuel pressure regulator. Then run about 4-6" of silicone tubing instead of the factories 4-6' of tubing. The 4 into 1 barb will live a much longer life if you move it away from the heat source of the turbo. The factory could have really helped themselves and others by doing that one simple relocation.
Yes, Thanks for catching that.
I had a single cup of weak coffee yesterday.
I'll edit it.

I've looked into the silicone tube also, and read that it "could collapse partially or fully due to the soft wall construction and properties of silicone.
I haven't tested any silicone myself, so I can't say for sure if that's the case.
 

·
Registered
Joined
·
281 Posts
Not sure if anyone has mentioned it but if you do "T" it into the Map Sensor line don't be alarmed when you see the needle momentarily dip (go back towards zero on idle) from time to time. That is because the Barometric solenoid is plumbed in with the MAP sensor line and takes samples of the Barometric pressure.....Perfectly normal. I have my '86 GLH Turbo's boost gauge plumbed this way.
 
1 - 18 of 18 Posts
Top