hello, i have an 85 gs with an rb holly 465 carb, anytime i rev past about 5k rpm the engine starts vibrating badly and starts sounding pretty bad to, it will rev up to redline but i'm afraid to rev it that high becouse i'm not sure whats wrong with it. any ideas? thanks.

 

did this get posted? i cant see it on the board.

 

bogging due to fuel starvation.

 

Snap a pic of you intake and carb set up and we'll see.

 

i don't have any way to post a pic but it is the rb holley stock port intake kit: the one that has the holley 465 carb and the manifold to.

 

do you think the jets might be to small? they say 49 on them. i'm also running a carter fuel pump at 7 psi , i did have a cheap autozone pressure regalater on it but it was only letting it get about 4.5 psi so i took it off, it ran a little better after that.

 

bump

 

bump

 

vacuum advance disconnected?

 

no.

 

How is your fuel pressure? Regulator should be set at 6 psi. How is the float level? Check both float bowl sites.

 

float is right, fuel psi is about 7-9 psi; i have a cheap autozone psi gauge it sucks.

 

Ok start here adjust your float levels properly, set the fuel pressure at 5psi, make sure your air/fuel mixtures are ok mine are set to 3 counterclockwise turns from fully seated, finally make sure when the engine is warm the choke plate is fully opened.

hope that helps.

 

7 - 9 psi? Does your needle on the fuel pressure gauge fluctuate that much? Should be steady at 6. 9 is alot.

 

ok, floats are right, do you mean the idol mix screws? Do you think i need a better fuel pressure regulator? Is 1 to 3 PSI more than recomended bad at high RPM?

 

Auto Zone BULLSHIT

 

You should check your vaccum secondaries to see that it's working right. Maybe the diaphram needs replacing. Pictures would be helpful.

 

The carb was installed in August of '06

 

How are you checking the floats? The fuel should just dribble out. Fuel pressure is too high, should be at 6 psi. What are you using for an air filter (size, etc). You can purchase a secondary spring kit from any speed shop and change the rate of opening on the secondaries (don't lose the checkball).

 

yes fuel dribbles correctly, air filter stock racing beat filter that came with the RB intake kit ; Do you think that the opening rate on the secondaries would be impotant at 5 K RPM ?

 

Not the idle mixture screws. There is a screw on the side of the float bowl. Take the screw off and you should see some fuel come out when you shake your car. I would use a good fuel pressure regulator and a good gauge so that you can monitor the fuel pressure when you want to. more psi the better, but your RB Holley should run fine at 6 psi.

 

Do you think that the opening rate on the secondaries would be impotant at 5 K RPM ?

yes

 

okay, Im using the stock spring that came with the stock RB kit
which one should i be using

 

Sounds like a similar problem to mine mabey. Hits 5000rpm then kinda just dies and shutters a lot. Difference is I have an edelbrock with mechanical secondaries.

 

Have you verified the ignition timing? Maybe run some seafoam through it in case of a sticking seal?