Vacuum gauges fluttering wildly, trying to sync my carbs

[Rodsquest]

What is used to stop a vacuum/fuel pressure gauge from wildly swinging back and forth when connected to the vacuum ports on the intake manifold of my 2003 F90TLRB?. I think there should be a one-way inline valve on the hoses or? I have four new gauges that are for both vacuum 0-30 in.hg and fuel pressure 0-15 psi to use a a manometer to sync. my carb's.

Thanks for any info.

Rod

[99yam40]

That is the reason they make special equipment for doing this, not just using cheap stuff not made for it.

Possible a small orifice in line with it would snub some of it, but finding the right size would be interesting

[rodbolt17]

either BK oe orecision instruments makes a 4 channel manometer for about 150 dollars.
my tech mate was about 650.
a standard northern hydraulics press/vac gauge wont work.
at a minimum it has to be a dampend meter.

[seahorse5]

When I did a lot of motorcycle work, we would use those needle type aquarium air valves in line with the vacuum gauges. You could slowly close the valve until the gauge needle would barely move at engine idle, yet would respond to adjustments.

[TownsendsFJR1300]

What is used to stop a vacuum/fuel pressure gauge from wildly swinging back and forth when connected to the vacuum ports on the intake manifold of my 2003 F90TLRB?. I think there should be a one-way inline valve on the hoses or? I have four new gauges that are for both vacuum 0-30 in.hg and fuel pressure 0-15 psi to use a a manometer to sync. my carb's.

Thanks for any info.

Rod

I've used a "Carbtune manometer" on my F150. Its designed for a 4 cylinder engines including outboards but will handle the larger engines. There is a restrictor that goes in-line and dampens the vacuum considerably. No liguids, very, very well made.

Short of a professional, computer, for the do it yourselfer, a great tool.. I've had it several years, at the time I had to order it from the UK, less than $90.00 to my door...

www.carbtune.com