Got the new carb installed! - Question for ya-

[JMP]

Switched out the ol 2 barrell holley for a 4 barrell this weekend (4160) and put on a edelbrock performer intake manifold, I am stoked. Runs and starts much better and I can feel that the power increased.

The only thing aside I have not been able to get tuned is every now and then there is some throttle lag when getting up and going in first. Any thoughts and suggestions for a new guy setting up his carb?

TIA;D

Josh

 

[bannind]

Off the top of my head I would say check timing and make sure your ported vacumn advance is hooked up properly.

 

[ugly74]

look at the accelerator pump linkage while opening up the throttle. the arm at the pump must begin to move at the exact same instant that the throttle begins to move.
if that's all tight, you may need to tinker with pump cams and/or squirters.

 

[JMP]

The ported vacuum is on correctly.

Reminds me though. There is also a inlet on the opposite side of the fuel inlet on the front passenger side of the carb that was not indicated in the instruction manual. Ideas as to what this is, and where that goes may solve the issue.

 

[bannind]

I thought that the ported vacumn was the one located 1/2 way up the fuel bowl on the passenger side. Of the two underneath coming directly out the front one is the PCV and the other is full vacumn. Of course I could be remembering the wrong carb, so take it for what it is worth. Just gotta make sure that all the ports are capped up if they aren't in use.

 

[JMP]

You are right it is half way up on the pass back for the vacuum advance, but the one I am referring to is on the front of the pass side directly across from the fuel inlet.

dont know what it is and it is not in the manual that I printed from their web page. Had a buddly look at it and he didnt know what it was either.

Here is a pic, hope it works- Top passenger front of the carb-

http://s69.photobucket.com/albums/i54/synapse321/?action=view&current=103.jpg

 

[broncnaz]

I believe its just a extra constant vaccum source although it could be ported also.
one other thing to consider is that the accelerator pump squirter itself may be to small or to large I find that a #28 or 31 will usually work good on a 302

 

[bushman]

I had the same problem on 2 vehicles, and rejetting solved the problem. On an intake with larger runners and/or plenum volume, the vacuum signal the carb sees is weaker, so a carb that runs awesome on a small intake will not meter enough on a larger intake and run lean, requiring moving up a size or two (jets). Upping the accelerator shot may cover up the problem, but may lead to a bogging condition on take-off. Just my .02/experience

 

[JMP]

Cool, then I will plug the constant vacuum and increase the size of the jets. See if that works.

Working on Plug wires and spark plugs now...Ya-all gap at 35 thousandths?

Thanks again for the info on the carb.

Josh

 

[daddyg]

I am running a 31 shooter in my Holley 470 TA and it seems about right for my 302.

 

[ugly74]

JMP,
whatever you do...change one thing at a time, and keep track of the changes ya make.
If you've got an open vac port, plug that 1st and then see where it's at then.

if you've got a hesitation/bog right off of idle, jets aren't going to make much, if any difference.

 

[JMP]

Plugged the inlet in question and it runs like a dream now! I am stoked.

Then I put in some new spark plugs, wires on and changed the oil. The Bronc wants to fly!

Thanks for the help guys, just gotta wait for the air cleaner and I can get her back on the road...

Josh

 

[JMP]

Alright, just getting around to ordering some new squirters...

think I will go with the size 31's, I found the replacements but there are two kinds

Question -Tube Style or straight. Which do ya'all prefer?

Thanks

Josh

 

[rcmbronc]

I like the tube style, but cant verify if they work any different than the straight style.

 

[malcolmzilla]

Subscribing, puttin a 470 TA on my 302 right now! Good info here!

 

[JMP]

Couldnt find the straight style in Summit so I ordered the tube style.

Zilla - What do you mean?

Thanks for the feedback

Josh

 

[malcolmzilla]

Good feedback on what to tune / adjust, my carbs goin in next day or so and is a Holley Truck Avenger.

 

[JMP]

Lag on take-off Holley 4160 - cause???

Ahh, Zilla I see what you meant. You have an install thread going as well..And ooo, nice carb - thought of that one but my pocket didnt want to float that kinda coin-



Well argh - swapped out the squirter to a 31, but well, I replaced a 31 with a 31) - figures...

What else could be causing lag on take off? Timing? Lean/Rich? I am baffled...ideas?

I just reread the thread. Pump Cams and timing were listed - Is there a "How to" link for adjusting the pump Cams?

Thanks