Boost gauge not working...Help.....

[Sinical]

I bought a AutoMeter Sport comp boost gauge and installed into correctly I believe, the problem I'm having is that it reads -5 vac. What could be causing this? My stock boost gauge works so I'm stumped. I made sure that plastic tube has no kinks (I did put a couple kinks in while installing unfortunately but straightened them the best I could).

Edit: I am aware that my header is cracked (typical header crack on these cars) but would this cause the gauge not to work?

 

[jurassic five 7]

Does it read -5 VAC all the time, even when you're in boost? Or does it only when you're at idle?

Also, stock boost gauges arent accurate.

-Adam

 

[Sinical]

Does it read -5 VAC all the time, even when you're in boost? Or does it only when you're at idle?

Also, stock boost gauges arent accurate.

-Adam

All the time, idle and when I'm giving it gas. I even pulled out of the garage to have the engine under load.
I'm uploading pics just so maybe someone can verify I connected to the right vac line.

Yea, I'm aware that the stock boost gauge sucks, I was just putting it out there in case it was pertinent info.

 

[Sinical]

This is the line I T'd off of

It lead here:

Then I did as the GNTTYPE article told me to:

 

[jurassic five 7]

Maybe try a differnet vac hose? Like the one that goes to the FPR. I tried to go trace mine but i got too many hoses so i couldnt find it, sorry.

-Adam

 

[SHADOWII]

Try putting...

a mighty-vac on the gage to see if it is working. the line you are attached to should be the correct one going to the map sensor. also the original tb block is known to leak. I always use form-a-gasket to seal that puppy up. the hose to the metal tubing may be split on the bottom of the hose like one of mine were, and that after having been replaced 2 weeks earlier. try eliminating the map sensor, (remove the T and connect straight to the gage) to see if it opporates correctly. that would eliminate that part of the equasion. if it works, the tubing,connecters,or map is bad. If you still don't have any vac. you will have to eliminate the hoses one at a time. remember, you do have check valves in the tb blk circuit. starting from the front of the block, the 1st goes to the fuel canister, the2nd to the egr. (which is something to investigate to insure it is closed and not leaking)
Keep us informed, there is always someone here to help.:smile:

 

[Sinical]

a mighty-vac on the gage to see if it is working. the line you are attached to should be the correct one going to the map sensor. also the original tb block is known to leak. I always use form-a-gasket to seal that puppy up. the hose to the metal tubing may be split on the bottom of the hose like one of mine were, and that after having been replaced 2 weeks earlier. try eliminating the map sensor, (remove the T and connect straight to the gage) to see if it opporates correctly. that would eliminate that part of the equasion. if it works, the tubing,connecters,or map is bad. If you still don't have any vac. you will have to eliminate the hoses one at a time. remember, you do have check valves in the tb blk circuit. starting from the front of the block, the 1st goes to the fuel canister, the2nd to the egr. (which is something to investigate to insure it is closed and not leaking)
Keep us informed, there is always someone here to help.:smile:

The one thing that comes to mind is that I did replace a vac hose recently that was cut in 2. I apologize for not knowing the correct term for this hose. I just bought a new piece of hose and replaced it (no check valves or anything).

Here's the hose that I replaced:

This was the other half of the line that lead nowhere, as you can see it had a larger piece of vac hose that I believed was supposed to connect the 2 halves.

As I said, I replaced it with a new hose, was there supposed to be something else (check valve?) in/on the hose? I simply connected it to the cannister. Also, I apologize for the noob question but can I just go to the parts store and buy said "check valve"? I'm not even sure what it looks like.... Would this cause my boost gauge to not work?

Thanks for the help.

 

[ES1]

There are 2 vacuum hoses that go to the cannister, the smaller one has a check valve, the larger one does not.
The check valve will look like the one that goes to the EGR.

Was the boost line crimped?

 

[Sinical]

There are 2 vacuum hoses that go to the cannister, the smaller one has a check valve, the larger one does not.
The check valve will look like the one that goes to the EGR.

Was the boost line crimped?

Ok the smaller line is the one I replaced and I do not have a check valve on it. Is the check valve just a TEE that is open at one end? Also, to try and diagnose I have connected the gauge directly to the vac block and it now reads -20 vac at idle and when I give it gas it goes to -5-10 vac. The line was crimped in a couple of places thus I connected it right to the vac block. I will just replace the whole line and be more careful this time around. The Nylon line sucks to try and route.

Would that line not having the check valve cause the gauge to work incorrectly? Is the check valve something I buy in the "HELP" section of the parts store?

 

[ES1]

You should be able to get the valve at the HELP section.
Look at the EGR hose on the driver's side valve cover.
That is the type of valve needed.
Not sure on the guage not working but would think the crimp was the problem.
I had trouble with the nylon line crimping so I connected the nylon line to a rubber hose to keep the line from crimping in my boost guage holder.

 

[Sinical]

You should be able to get the valve at the HELP section.
Look at the EGR hose on the driver's side valve cover.
That is the type of valve needed.
Not sure on the guage not working but would think the crimp was the problem.
I had trouble with the nylon line crimping so I connected the nylon line to a rubber hose to keep the line from crimping in my boost guage holder.

OK I'll take a trip to the parts store to correct that problem at least. I would think that the gauge would work once I connected it directly to the vac block though since the nylon line is out of the equation? Would the size of hose be a factor?

Anyone have a picture or a link showing this check valve? I just went to the valve cover and I'm not sure which it is.

 

[Gary Wells]

Ok the smaller line is the one I replaced and I do not have a check valve on it. Is the check valve just a TEE that is open at one end? Also, to try and diagnose I have connected the gauge directly to the vac block and it now reads -20 vac at idle and when I give it gas it goes to -5-10 vac. The line was crimped in a couple of places thus I connected it right to the vac block. I will just replace the whole line and be more careful this time around. The Nylon line sucks to try and route.
Would that line not having the check valve cause the gauge to work incorrectly? Is the check valve something I buy in the "HELP" section of the parts store?

----------------------------------
Gage appears to be working correctly now as you have described it, should read 0 with the engine off, about 16-20 in park at idle with the motor cold, and sometimes slightly less vacuum with the motor warmed up. HTH

 

[Sinical]

So it will pull vac at idle?

 

[Gary Wells]

Ok the smaller line is the one I replaced and I do not have a check valve on it. Is the check valve just a TEE that is open at one end? Also, to try and diagnose I have connected the gauge directly to the vac block and it now reads -20 vac at idle and when I give it gas it goes to -5-10 vac. The line was crimped in a couple of places thus I connected it right to the vac block. I will just replace the whole line and be more careful this time around. The Nylon line sucks to try and route.
---------------------------------
According to your description, it is pulling vacuum. -20 vacuum at idle means that the motor is pulling 20 inches of vacuum. At idle.
With your motor not running, your gage should read 0
With your motor running at idle in park, gage should read about 17-20 inches of vacuum when cold, slightly less when warm. Relative figures. When you give it gas, you are really opening the throttle blade, removing some of the vacuum, and your gage will decrease it's vacuum value. When you go into boost, the gage should read 0 on a vacuum gage, or a positive value expressed in lbs psi on a vacuum-0-boost gage.

 

[Sinical]

Ok the smaller line is the one I replaced and I do not have a check valve on it. Is the check valve just a TEE that is open at one end? Also, to try and diagnose I have connected the gauge directly to the vac block and it now reads -20 vac at idle and when I give it gas it goes to -5-10 vac. The line was crimped in a couple of places thus I connected it right to the vac block. I will just replace the whole line and be more careful this time around. The Nylon line sucks to try and route.
---------------------------------
According to your description, it is pulling vacuum. -20 vacuum at idle means that the motor is pulling 20 inches of vacuum. At idle.
With your motor not running, your gage should read 0
With your motor running at idle in park, gage should read about 17-20 inches of vacuum when cold, slightly less when warm. Relative figures. When you give it gas, you are really opening the throttle blade, removing some of the vacuum, and your gage will decrease it's vacuum value. When you go into boost, the gage should read 0 on a vacuum gage, or a positive value expressed in lbs psi on a vacuum-0-boost gage.

Aww thanks for clearing that up. Well I think I now have it hooked up correctly, the gauge was reading as you described at idle, and when I gave it gas, I didn't drive the car which I should've. Well I'll have to wait now since I bent and broke the steel emmision vac line. I'll order a new one from Kirban along with a new billet vac block.

Thank you very much, I learned alot today.

 

[Gary Wells]

If you are running a vacuum gage only, you might want to consider upgrading to an aftermarket combination vacuum-0-boost gage, and that would give you a better idea of what the motor is up to. Will allow you to keep an eye on boost also at the same time on the same gage.

 

[SHADOWII]

If you ...

haven't discovered what the check-valve looks like, look at your 1st pic you posted. It is the black&white, plastic wafer looking item attached to the hose going to the egr valve, resting on the valve cover. looks to be about 3" from your finger.

 

[Sinical]

haven't discovered what the check-valve looks like, look at your 1st pic you posted. It is the black&white, plastic wafer looking item attached to the hose going to the egr valve, resting on the valve cover. looks to be about 3" from your finger.

Thank you very much, I'm going to hit the parts store on the way home.

On another note, anyone know where I can buy the 2 steel lines that come off of the 2 back ports of the vac block? I broke mine while fooling around trying to get this boost gauge to work and replacing the vac hoses coming off of the vac block.

My 05 Kirban catalog had them listed but they have since been discontinued, the local dealer is telling me they are no longer available.

 

[TURBOELKY]

poston had them last year? if not look in the parts for sale section, or place a post in the parts wanted!

 

[SHADOWII]

Or try ...

Brian at GBodyParts.com/717-359-9692. He may have them also.