Bouncing Boost Gauge

[Sipey]

Evening all.

Quick question for anyone that may know an answer. I have recently fitted a boost gauge to me brum brum. All is fine in the first 10 mintues but then the needle starts to bounce.

On acceleration the needle moves swiftly to 5 psi and stays there until gear change. When changing gear it shoots down to 23 in vacuum, before climbing again to 5 psi - again nice and steady.

The problem is at idle. When you first start the car the needle holds steady in vacuum at 20. But after 10 minutes or so it bounces between 14-22. Also, when pootling with your foot on the throttle maintaing a steady speed it will bounce in the same range.

Any ides peeps - all suggetions greatly welcomed :)

[Fargo]

thought the tte s/c only ran max .3 psi boost...

[Sipey]

.3 bar Fargo matey which is around 4.5 psi

[Monster-Mat]

where is it plumbed in.

[Sipey]

lower pipe down near the throttle cable Mat

[Fargo]

.3 bar Fargo matey which is around 4.5 psi

←

ahhh i thought that cant be right....

[Monster-Mat]

did you get a small brass "thing" with a hole in it with the guage, thsi is supposed to go in the pipe..it balances the -/+ in the tube

[Sipey]

I did Mat but there aint no way it will fit in the pipe - the pipe goes through the brass thing

[Monster-Mat]

I did Mat but there aint no way it will fit in the pipe - the pipe goes through the brass thing

←

nope the one im on about is a tiny little thing, bit like a tiny egg with a hole in it.....

which Guage have you got

[Sipey]

Yep, tiny little gromit type thing shaped like <> with a hole through it

It be an AC gauge mate

[marcus]

Yep, tiny little gromit type thing shaped like <> with a hole through it

It be an AC gauge mate

←

You have to use that bit or it will jump all the time ;) :winky:

[Sipey]

I have used that bit but the hole in it is larger than the pipe supplied. The gauge does not bounce all of the time - only when the car has been running for 10 minutes. Switch off and turn back on again immediately and it does not bounce - this is what I cannot understand.

Could it be a problem with the throttle - I took the pipe off of the back of the gauge and rather than a steady airflow it pulses - which is what is causing the gauge to bounce.