Truck Avenger

[pvfjr]

Now when my 78 Stepside was falling on its face, I was tired of messing around with the old Quadrajet. So I bought a brand new Holley Truck Avenger (670 CFM). Supposed to be bolt on and go more or less, so I bolted it on and went-but not very well. It idles way too fast and is adjusted all the way down. Also, my top speed has gone down from over 80 to about 60-65 where it starts acting like it's starving out. Since I had to use a adapter plate, I'm thinking vacuum leak. I would like to take it back apart and use some sealant, but someone told me not to use silicone. What should I use? I would like to think that it is not the carb, could a leak cause all this? Could it be in the intake?

 

[supersize75k5]

I had the same issues /forums/images/graemlins/crazy.gif

 

[TWISTEDJACK]

Did you adjust the idle circuit as well as the idle adjustment? I have one of these on my truck(770cfm) and it wasn't an out of the box bolt on and go. Holley's take a little tuning but I am happy with the way mine works after I got it dialed in. It would be hard to get one carb to work on every motor at every elevation. They all take a little fine tuning if you want to get the most out of them. Even the q-jet needs a little tweaking on some motors.

 

[pvfjr]

?

 

[TWISTEDJACK]

I am talking about the adjustment screws on the side of the metering block. Those set how rich/lean it is at idle.

 

[pvfjr]

It's been a while since I've messed with it. Tranny went out in Dec, and I'm in the middle of a conversion. I don't think I messed with that adjustment, though. Messed with the idle speed, and the fast-idle speed. I'm at 400 ft elevation, so it shouldn't be too weird.

 

[pvfjr]

Any other ideas out there? Also I didn't mention that the speed is also unstable. Sometimes too high, sometimes really high.

 

[Z3PR]

Just need to ask, do you have a silanoid for A/C at the carb ??? If so, sometimes those need to be adjusted down. Possible throtel cable adjustment also. Just thinking outloud.

 

[pvfjr]

No A/C solenoid. Just the carb straight out of the box. Problem is also there even with the throttle cable disconnected.