Ugh, boost guage just died

speedsix

Leon Cupra R 225
Oct 30, 2004
825
0
Got in the car this morning, did a TBA, started driving and noticed the guage won't go higher than 2-5psi. Assumed limp mode but car is boosting strong. Guage goes into vacuum fine. Check hose, looks ok. Dodgy guage? Anyway of testing it?

Cheers

Dom
 

dj_hektik

LEON 20VT FR
Happened to me when I installed my gauge the forst time, the pipe from the FPR to the gauge melted, but that's cause I used a cheap plastic pipe - the one I got with the gauge was not long enough. When I used the proper nylon tube everything was OK.

or try another gauge?

can't think of anything else.
 

speedsix

Leon Cupra R 225
Oct 30, 2004
825
0
I did think the hose may have melted, I used the supplied stuff and it gets very soft. Couldn't see a split but I'll have another look.

Did you get wierd readings i.e vacuum but no boost?

What 'size' tubing do I need?

Cheers
 

Copra

Used To Be "mk4polo"
Feb 7, 2003
2,616
0
Hampshire
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i think its 4mm i.d pipe, dont quote me on that though.

if you get a split pipe, i would have thought the readings all over the scale would be out, ie boost and vacuume
 

dj_hektik

LEON 20VT FR
I did think the hose may have melted, I used the supplied stuff and it gets very soft. Couldn't see a split but I'll have another look.

Did you get wierd readings i.e vacuum but no boost?

What 'size' tubing do I need?

Cheers

yes I got vacuum and less boost. If that's what you see i think it's definitely the pipe.

When I ordered the gauge from EIP, they told me to use the grommet under the wiring loom - I was using that for the ICE power cable, so I used a grommet I found behind the turbo - that's why it got so hot.

I ordered a another pipe and it was fine, even here in Saudi heat (it's been 45-55 degrees for the last 5 months) and I have no issues. Routed it back near the N75 then into the grommet behind the wiring loom
 
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speedsix

Leon Cupra R 225
Oct 30, 2004
825
0
I'm pretty sure it's the pipe, moved the pipe and now losing lots of boost, guage is doing some funky things aswell.

Got some 6mm nylon hose from Halfrauds, slightly larger diammeter but should clamp tight enough. T piece has variable sized 'notches' so should be ok.
 

speedsix

Leon Cupra R 225
Oct 30, 2004
825
0
The stuff I've bought is the same type as all the other black hoses. DIY stores only sold the clear silicone hose like the stuff supplied by the guages.

There's not really anywhere 'away' from the heat in a cupras engine bay! ;)
 

speedsix

Leon Cupra R 225
Oct 30, 2004
825
0
Right, fixed it. Crappy silicone hose supplied with the guage had burnt and split. Fitted the thick rubber(same as other vacuum hoses) hose and the gauge behaves completely differently. Instead of being twitchy it's now slower and smoother!?? When you back off the throttle the needle drops slower than it did before. Odd.

Why would the gauge be slower reacting with the new hose?? I can't see any kinks or anything, piping is slightly larger diammeter but that wouldn't matter would it?
 
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Tallpaul

Full Member
Jul 2, 2005
821
0
Is the internal volume of the new hose significantly bigger than the one you had previously ie is it longer and/or a wider bore?
 

speedsix

Leon Cupra R 225
Oct 30, 2004
825
0
Original was 4mm diammeter, new stuff is 6mm, smallest I could get hold of.

I don't think it's reaching the correct reading quick enough, it does hold the correct value but there's no overboost visible now.

It's an Autogauge smoked.
 

Tallpaul

Full Member
Jul 2, 2005
821
0
i'd say that moving the bigger volume of gas inside the hose has reduced the speed. The spring inside the gauge is still the same size. IIRC my old boost gauge had a recommended max i.d. for the hose.
 

speedsix

Leon Cupra R 225
Oct 30, 2004
825
0
Fitted the 4mm, gauge is faster now. Not as fast as the original hose but just right, smoother aswell.
 
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