Hello every one long time no see.
I having a problem with my holley,
I can not get it to tune. It's runing like I have a vaccume leak some where.
But I can not find it I've check every thing i've put new lines every where even the ac controlls under the dash.
The only thing I can think it is is my power brake booster, when I push the break in and let it go the engine revs real high then drops down..
i've put 3 boosters on it and its dose it with every one. I am now out of ideas.
I've checked every thing I can think of gaskets, lines made sure all the bolts on the manifold where tight and to specs. any ideas?
the carb keeps blowing power valve's back fires through the carb, runs rich smokes, stumbles, loads up idels rough, new carb only a month old.
timing is good, new plugs and wire's new coil, cap and rotor, I have a aftermark jegs Vaccum can with all the check valves where they sould be, the engine is only 2 years old.
Is there some thing i've missing or if the booster is the problem could I get 3 bad boosters?
I have a Edelbrock, and the brock dose the same thing it runs rich and rough smokes dosent seem to want to tune right.
any help or ideas please.
Thank you





600cfm
Vacuum Secondary
Electric Choke
runing #65 main jets
same size power valve

 

You might want to check the fuel pressure. It could be too high. 4 to 6lbs is plenty.

 

I forgot. I have it set at 4 and a half to 5.

 

Try spraying carb cleaner along the intake where it meets the heads and around the carb gasket. If the idle changes, you found your leak.
You might try plugging the brake booster line to verify that it isn't bad.

 

Thank you I tryed those and it was doing the same thing.
Some thing came to me at work I wondered if it might be my spacer..
Well I got a few of my old spacer's and tryed one and it stoped. its runing great.. how in the world could a spacer make this much trouble..

 

I must be warped or something.
Glad you got it fixed though

 

Ya me to.
by the way Lx, I love your 77 150.
Thats the year truck i'm looking to get next.
I bet its a road and gas eating machine.
then its going to be a Fox bod mustang with a 460Cobra jet stuffed in to it.. that will be fun.

 

Yeah, the old beast will pull a house off of it's foundation, but around town only gets about 6mpg. That's why I don't drive it anymore
I should put the 460 in my LX