Rank: Member
Groups: Registered
Joined: 24/03/2007(UTC)
Posts: 41
|
gday,
i recently bought a speco boost/vac gauge, ranging from vac 30-0-30 boost to use to check vacuum on my 253. I used the supplied t piece and fittings, but when connected at idle it sits on 0 and with a quick hit of throttle the needle jumps to maybe 5 then straight back to zero. My engine is only mild, 253 quaddie/kc manifold/elec ign, but i really did expect to see more of a reading. Does this seem right, or can someone please point me in the right direction?
Thanks
Nathan
|
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 17/04/2005(UTC)
Posts: 465
|
I know exactly what has happened (as I did it myself and fell into the same trap).
You have connected into the venturi vacuum port, which controls the vacuum advance in the distributor.
You need to connect to the manifold vacuum port, which is eithe |
__________________________________________
Keep the shiny side up, and the greasy side down. |
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 24/03/2007(UTC)
Posts: 41
|
thanks jabba. How much vacuum should i be expecting my gauge to read?
ill swap some hoses around tomorrow and see how i go.
cheers
|
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 24/03/2007(UTC)
Posts: 41
|
thanks jabba. How much vacuum should i be expecting my gauge to read?
i'll swap some hoses around tomorrow and see how i go.
cheers
|
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 17/04/2005(UTC)
Posts: 465
|
You should expect around 20" at idle. A lumpy cam may only give around 8". Engine braking it should climb to 25 - 30". Cruise should be 15 - 20". (That is what I am seeing on my tired 350.
j
__________________________________________
Keep the sh |
__________________________________________
Keep the shiny side up, and the greasy side down. |
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 24/03/2007(UTC)
Posts: 41
|
|
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 17/04/2005(UTC)
Posts: 465
|
No probs.
How did you get on?
__________________________________________
Keep the shiny side up, and the greasy side down. |
__________________________________________
Keep the shiny side up, and the greasy side down. |
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 24/03/2007(UTC)
Posts: 41
|
yeah good mate, soon a u tapped into the correct line i could her the pssssssss froma mile away. It sits on about 12-15 on idle. Thanks very much again for your help mate
cheers nathan
|
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 17/04/2005(UTC)
Posts: 465
|
A hiss noise doesnt sound good. give it a spray with CRC or WD40. Figure out if there is a vacuum leak and plug it.
12-15 is pretty good for a mild engine.
__________________________________________
Keep the shiny side up, and the greasy side d |
__________________________________________
Keep the shiny side up, and the greasy side down. |
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 17/04/2005(UTC)
Posts: 465
|
A hiss noise doesn't sound good. give it a spray with CRC or WD40. Figure out if there is a vacuum leak and plug it.
12-15 is pretty good for a mild engine.
__________________________________________
Keep the shiny side up, and the greasy side |
__________________________________________
Keep the shiny side up, and the greasy side down. |
|
|
|
|
|
Forum Jump
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.
