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Boost Gauge Diagrams
- Thread starter TURBO1
- Start date
TURBO1
Super Cool Member
So I found a broken vac line from the intake to what looks like a small black vac line going into the harness then into the firewall, is this right?
I hooked up my mighty vac pump to it to see if I can get the boost gauge to move, but got nothing. I don't have a service manual yet & still new to the LC2 engines.
I also removed the cluster assembly thinking the was a vac port dissconnected, little did I know theres is no vac port & its electrical?
Can someone confrim with me, it goes into the firewall a vac line then somewere it goes into ? then turns electrical,I'm not the only one to run into this, any ideas or ways to check it operation? Thanks!!!
-Jason
I hooked up my mighty vac pump to it to see if I can get the boost gauge to move, but got nothing. I don't have a service manual yet & still new to the LC2 engines.
I also removed the cluster assembly thinking the was a vac port dissconnected, little did I know theres is no vac port & its electrical?
Can someone confrim with me, it goes into the firewall a vac line then somewere it goes into ? then turns electrical,I'm not the only one to run into this, any ideas or ways to check it operation? Thanks!!!
-Jason
WS6
Stay thirsty my friends
I don't have intimate knowledge of the factory boost gauge, but I do of the factory manual and I recall no schematics of it and very little reference to it. I do believe that is a simple 0-5V voltmeter that reads parallel voltage off the MAP sensor.But I'm not sure.
I can suggest that you ignore it alltogether because they are notoriously inaccurate. You need a mechanical vacuum/boost gauge to be sure.
That plastic line is probably to power the HVAC system and all the vacuum motors associated with it.
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I can suggest that you ignore it alltogether because they are notoriously inaccurate. You need a mechanical vacuum/boost gauge to be sure.
That plastic line is probably to power the HVAC system and all the vacuum motors associated with it.
...
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WS6
Stay thirsty my friends
I guess "controls it" is accurate enough.
Try this for vacuum routing for the engine compartment. The line labeled HVAC goes through the firewall and is parsed out to run defrost,floor heat flappers and anything mechanical that needs moved around in the dash related to heating and AC.
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Try this for vacuum routing for the engine compartment. The line labeled HVAC goes through the firewall and is parsed out to run defrost,floor heat flappers and anything mechanical that needs moved around in the dash related to heating and AC.
.
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TURBO1
Super Cool Member
Cool, thats what I was looking at also, I've attached some photos, if coming off the intake goes to the map, then mine might be hooked up wrong, take a look at the pictures & let me know if its correct. I did jump the map sensor black & green wires (key on engine off) & the boost gauge jumped to full 20 psi, so I know the gauge works. Thanks for any helpI guess "controls it" is accurate enough.
Try this for vacuum routing for the engine compartment. The line labeled HVAC goes through the firewall and is parsed out to run defrost,floor heat flappers and anything mechanical that needs moved around in the dash related to heating and AC.
.
..
lease:
WS6
Stay thirsty my friends
Dude...and I don't use the word dude lightly...you got some 'effed up vacuum routing,open vacuum souce.
Don't push that car hard till you get those fixed first....and your MAP isn't seeing vacuum the way it's hooked up now. And that's why your boost gauge doesn't work.
I'll get back with you later.
Don't push that car hard till you get those fixed first....and your MAP isn't seeing vacuum the way it's hooked up now. And that's why your boost gauge doesn't work.
I'll get back with you later.
TURBO1
Super Cool Member
Cool, thats what I was looking at also, I've attached some photos, if coming off the intake goes to the map, then mine might be hooked up wrong, take a look at the pictures & let me know if its correct. I did jump the map sensor black & green wires (key on engine off) & the boost gauge jumped to full 20 psi, so I know the gauge works. Thanks for any help
Well, I found some info & they way its routed on my car is wrong. The MAP hose goes the the intake runner as per the diagram. The wastegate solenoid port should be open w/a foam filter? Does this sound right? At the wastegate solenoid does the filter go on top or the lower port? My "Y" connector hoses from the turbo/wastgate go to the lower port on the solenoid, is this right? So the only thing I need to find is were the small black vac hose coming out of the harness connects too.
WS6
Stay thirsty my friends
First,that device with the RED plug mounted on the valve cover is the wastegate solenoid. One end hooks up to the vac line from the turbo's " Y" fitting and the other end is vented to the atmosphere.
So remove that vac line that goes to the MAP sensor and pitch it. Next go get yourself some rubber vacuum line,3 or 4" cable ties, and loctite 271 RED, also get yourself some assortment of T's and Y fittings and maybe some 1/8" hard plastic vacuum line and an assortment of rubber vacuum elbows.
That open 1/4" metal line from the vacuum block(on the doghouse) that runs towards the rear of the engine is for the MAP sensor. So either choke(w/adaptors) it down to to fit the 1/8" plastic line and then put a rubber vacuum elbow on it to mate up to the vacuum port on the MAP sensor and that should get your boost gauge working again.
Now the other hard line that is compromised just needs replacing,either by cutting out the bad section and splicing it with small rubber vacuum line. Or replace all of by fishing it to where it meets a rubber fitting under the dash or on the engine compartment.
I like using hard line because it doesn't collapse, but any fix is acceptable as long as you solve all vacuum leaks. I like to coat the connections with RED locktite and then zip tie them tight for extra insurance.
You should then run the car around and take note of you idle BLM's after it's been warmed up. In park,at idle.
High BLM's are a sign of a vacuum or pre turbo leak and the ECM is compensating by throwing fuel at it.
128 is ideal, but open loop chips may idle at 128-135.With O2's in the high 700's or low 800's.
So remove that vac line that goes to the MAP sensor and pitch it. Next go get yourself some rubber vacuum line,3 or 4" cable ties, and loctite 271 RED, also get yourself some assortment of T's and Y fittings and maybe some 1/8" hard plastic vacuum line and an assortment of rubber vacuum elbows.
That open 1/4" metal line from the vacuum block(on the doghouse) that runs towards the rear of the engine is for the MAP sensor. So either choke(w/adaptors) it down to to fit the 1/8" plastic line and then put a rubber vacuum elbow on it to mate up to the vacuum port on the MAP sensor and that should get your boost gauge working again.
Now the other hard line that is compromised just needs replacing,either by cutting out the bad section and splicing it with small rubber vacuum line. Or replace all of by fishing it to where it meets a rubber fitting under the dash or on the engine compartment.
I like using hard line because it doesn't collapse, but any fix is acceptable as long as you solve all vacuum leaks. I like to coat the connections with RED locktite and then zip tie them tight for extra insurance.
You should then run the car around and take note of you idle BLM's after it's been warmed up. In park,at idle.
High BLM's are a sign of a vacuum or pre turbo leak and the ECM is compensating by throwing fuel at it.
128 is ideal, but open loop chips may idle at 128-135.With O2's in the high 700's or low 800's.
TURBO1
Super Cool Member
Cool, thanks for all the info, its a big help. Should the wastegate solenoid be replaced or just put a foam filter on it? I was told the "Y" vac hook up should be black on the TTA. Looks like some bodys been in there before me & its grey in color. I saw on Johns Performance website, he has the correct size restrictor, if I need it.
So off the vac block (dog house) its 1/4 hose, it can't stay 1/4 to the MAP? What size is it off the MAP? Do I just need to reduce the size going to the map? Thanks again!
So off the vac block (dog house) its 1/4 hose, it can't stay 1/4 to the MAP? What size is it off the MAP? Do I just need to reduce the size going to the map? Thanks again!
WS6
Stay thirsty my friends
I put the foam filter on...it was gone within a week or more, so I said screw it and I live without it.
1/4" sounds about right for either end,MAP and hard line at doghouse.
The Y could be grey, mine was and I repleced it once, and that one was grey too.
There is a difference in restrictor size from the GN and TTA orifice inside that Y. Order one from John...I think he still is selling off inventory.
1/4" sounds about right for either end,MAP and hard line at doghouse.
The Y could be grey, mine was and I repleced it once, and that one was grey too.
There is a difference in restrictor size from the GN and TTA orifice inside that Y. Order one from John...I think he still is selling off inventory.
Feel free to bring your car up to compare it to mine.
Sorry, but I don't drive mine around very much.
Maybe a few miles a month.
:beach:
Sorry, but I don't drive mine around very much.
Maybe a few miles a month.
:beach:
TURBO1
Super Cool Member
Boost Gauge Still doesn't work?
Its been a few weeks since I drove the car, I fixed the vac leaks & hoses at the MAP & Waste gate solenoid. I installed the .40' orffice in the gray Y connector line I received from Johns Performace for the TTA boost level.
My boost gauge is still not working, If I jump the 2 pins at the MAP, my gauge goes to 20psi. At the MAP it has the 4-6in harness that reverses the wires. Could there be a fault with the MAP? In the service manual it shows a boost sensor, is it refering the MAP or is it a different sensor? Tanks for any ideas!!!
Its been a few weeks since I drove the car, I fixed the vac leaks & hoses at the MAP & Waste gate solenoid. I installed the .40' orffice in the gray Y connector line I received from Johns Performace for the TTA boost level.
My boost gauge is still not working, If I jump the 2 pins at the MAP, my gauge goes to 20psi. At the MAP it has the 4-6in harness that reverses the wires. Could there be a fault with the MAP? In the service manual it shows a boost sensor, is it refering the MAP or is it a different sensor? Tanks for any ideas!!!
