[Sniz]

With the help of Mr. 5 IM'ng me last night I was able to get my x-line boost gauge installed for good. However I was unable to hook up the power wires so it has not backlight, no big deal. The problem is that its not reading any boost at all until I let off the throttle, then it will spike to 5psi or so. I know my car is making boost, I can hear/feel that I thought maybe I pinched the nylon line which is routed through the firewall to the gauge.

I had the car on a dyno this morning so it was a perfect time to troubleshoot the gauge. we attached 2 other manual boost gauges directly to the T in the vacuum line that I installed. The T is located at the split going to both DV's. neither gauge read any boost at all. Very weird. The car is obviously building some boost so we were puzzled. They had some sort of Tmap intercept machine that was able to pick up the boost reading no problem.

So my question is, how come the mechanical gauges all read 0 boost? Upon throttle closure i'm seeing spikes, but not during the actual boost/throttle at all.

I'm confused and frustrated.

[O-cha]

You should be confused as that makes absolutely no sense at all. Where did they intercept the TMAP? Maybe they got the faked signal from the procede and your cars just not boosting.



The only way I could imagine what you're describing is if you used one of the vacuum lines from the DV for your gauge, but didn't connect it back to the main line for some reason. That's the only way I could see a spike happening when you closed the throttle (from the diaphragm raising which would cause pressure there if the vacuum line was closed to your gauge.). I assume you're seeing no vacuum which makes sense in that situation too.

Maybe you didn't install it wrong like this but maybe the line is kinked somewhere between the T and the manifold, this would further explain things (your not getting much boost) because if so the DV would be opening at a low boost point (did you have forge because I can't imagine the stock valves would let you get up to 10psi).

[jadeddjay]

this might be a retarded suggestion but is your T valve ok? the one that came with my gauge looked clogged and it barely let any air pass. the one from newsouth was much better

[E82tt6]

Hmmm. When idling or coasting do you see vaccum?

[Sniz]

Originally Posted by jadeddjay

this might be a retarded suggestion but is your T valve ok? the one that came with my gauge looked clogged and it barely let any air pass. the one from newsouth was much better

you know what....I didnt take a look at it, I used the one that came w/ the gauge, not the one from new south which I do have.

I'm going to go swap them now. Only seeing spikes would make sense if the t-valve was pretty much clogged.

[Sniz]

Originally Posted by O-cha

You should be confused as that makes absolutely no sense at all. Where did they intercept the TMAP? Maybe they got the faked signal from the procede and your cars just not boosting.



The only way I could imagine what you're describing is if you used one of the vacuum lines from the DV for your gauge, but didn't connect it back to the main line for some reason. That's the only way I could see a spike happening when you closed the throttle (from the diaphragm raising which would cause pressure there if the vacuum line was closed to your gauge.). I assume you're seeing no vacuum which makes sense in that situation too.

Maybe you didn't install it wrong like this but maybe the line is kinked somewhere between the T and the manifold, this would further explain things (your not getting much boost) because if so the DV would be opening at a low boost point (did you have forge because I can't imagine the stock valves would let you get up to 10psi).

yeah confusing right???

I have the Forge DV's on the standard spring (green I think?). The lines are not kinked, at least not the factory ones. When we hooked up 2 other boost gauges directly the the T-valve there certainly no kinks. I cant say that for the nylon hose I have run to my boost gauge on my dash, that thing is pretty well crammed in between the dash and another panel.

they intercepted the T-map at the manifold so they were reading the actual values coming out the manifold (I'm assuming thats how the Tmap works). The cars tmap sensor then hooked into their machine so the car would operate correctly.

The car is 100% making boost. I can hear and feel it.

I'm going to swap out the T-valves and see if the cheap ass piece that came with the gauge is clogged and not letting air flow to the gauge.

[O-cha]

Originally Posted by Sniz

yeah confusing right???

I have the Forge DV's on the standard spring (green I think?). The lines are not kinked, at least not the factory ones. When we hooked up 2 other boost gauges directly the the T-valve there certainly no kinks. I cant say that for the nylon hose I have run to my boost gauge on my dash, that thing is pretty well crammed in between the dash and another panel.

they intercepted the T-map at the manifold so they were reading the actual values coming out the manifold (I'm assuming thats how the Tmap works). The cars tmap sensor then hooked into their machine so the car would operate correctly.

The car is 100% making boost. I can hear and feel it.

I'm going to swap out the T-valves and see if the cheap ass piece that came with the gauge is clogged and not letting air flow to the gauge.

I'm not talking about from the T to your gauge I'm talking about from the T to the manifold. The only way for what you have described to be happening is if no pressure was coming through the manifold through the vacuum line. So either it's kinked or the T is clogged on the side of the manifold vacuum line while the gauge and DV side are still open. Check both.

I know it's making boost, you said 10psi, that would not make sense if you had the stock diverter valves but it makes sense since you have the forge. The springs are probably around 10 pounds vs the stock springs which are about 4 pounds. So they will hold up to that point with no incoming pressure on the top (vacuum side) but they will open once it's reached.

[Sniz]

Ok I think I have the problem solved. i took the plastic T out of my car and blew as hard as i could into all 3 ends while capping another one off.......in 1 direction there is NO air passing thru. That'll do it right there.

I'm going use a needle and clean it out........all this headache because of a stupid little plastic T. I'm going to check the other T that O-cha mentioned as well.

[O-cha]

Originally Posted by Sniz

Ok I think I have the problem solved. i took the plastic T out of my car and blew as hard as i could into all 3 ends while capping another one off.......in 1 direction there is NO air passing thru. That'll do it right there.

I'm going use a needle and clean it out........all this headache because of a stupid little plastic T. I'm going to check the other T that O-cha mentioned as well.

No that was the T you needed to check and it makes sense provided the side that had no air coming out was connected toward the manifold. Could they have provided you with a T that had a check valve in it?

Replace the T and your car will start boosting again (correctly) too.

[Sniz]

Originally Posted by O-cha

No that was the T you needed to check and it makes sense provided the side that had no air coming out was connected toward the manifold. Could they have provided you with a T that had a check valve in it?

Replace the T and your car will start boosting again (correctly) too.

They provided me a T w/ a hunk of plastic in the middle of it. I can't pass air thru it in any direction. Greatttttttt waste of hours of frustration and $50 at the dyno.

I probably would have noticed something was up this morning but I was intentionally staying out of boost to keep everything cool for the dyno.

[Sniz]

Originally Posted by O-cha

No that was the T you needed to check and it makes sense provided the side that had no air coming out was connected toward the manifold. Could they have provided you with a T that had a check valve in it?

Replace the T and your car will start boosting again (correctly) too.

OK

we have boost and a functional boost gauge!


Another question. How much vacuum should I be reading when the car is idling? its going all the way down to 21-22. Just went on a quick full throttle run and it went up to 12-13psi. Car is at 90% on V2.

Should it be that low in vacuum??

[Mr. 5]

Originally Posted by Sniz

OK

we have boost and a functional boost gauge!


Another question. How much vacuum should I be reading when the car is idling? its going all the way down to 21-22. Just went on a quick full throttle run and it went up to 12-13psi. Car is at 90% on V2.

Should it be that low in vacuum??

Yes. The vacuum is normal.

[jadeddjay]

hours and some money spent but you learned something... you fixed it.. and thats great

i guess i my suggestion is not retarded afterall : P

[down4it]

Originally Posted by Sniz

OK

we have boost and a functional boost gauge!


Another question. How much vacuum should I be reading when the car is idling? its going all the way down to 21-22. Just went on a quick full throttle run and it went up to 12-13psi. Car is at 90% on V2.

Should it be that low in vacuum??

Vacuum is fine, thats right around where i am... -20 -21 -22 around there...

[down4it]

Back on the dyno you go...

[Sniz]

Originally Posted by jadeddjay

hours and some money spent but you learned something... you fixed it.. and thats great

i guess i my suggestion is not retarded afterall : P

Your suggestion was spot on! A light bulb went off in my head as soon as I read it....thanks!

[Sniz]

Originally Posted by down4it

Back on the dyno you go...

yup! maybe tomorrow, we'll see. I cleared my morning for todays dyno run .

[E82tt6]

My previous prediction still stands!

[Park2670]

My Stri gauge kit had that T that was clogged as well. I tried to blow in it and there was no flow whatsoever. Very crappy build

[NM_BMW]

Glad you found the problem. I question the build of the STRI gauge period. I"m on my second gauge and it is still off. My first gauge the needle was off a few lines. This second one I have was zeroed on arrival and then when I put it in the needle sits below zero a dash or more. I am debating about ditching the STRI and getting the VEI or Defi. I guess you do get what you pay for.

[335iheLLraiseR]

why is that vacuum so low/high? I just bought a boost gauge today and was looking at around the 20ish in the vacuum and was wondering if it would go that far.

[Sniz]

Originally Posted by Humtek

Glad you found the problem. I question the build of the STRI gauge period. I"m on my second gauge and it is still off. My first gauge the needle was off a few lines. This second one I have was zeroed on arrival and then when I put it in the needle sits below zero a dash or more. I am debating about ditching the STRI and getting the VEI or Defi. I guess you do get what you pay for.

I'm questioning the accuracy of mine too.........the question is, how can I check it? I would have to swap out another one right?

When should the gauge read zero? when its off??