TNTS70STANG

Hello again everybody! Yet ANOTHER adventure with my "DiscuStang"!

Can somebody please explain to me how to properly tune a Holley Street Avenger?

My carburater is fairly new at only 3 years old. I first had it installed on my 289 in which I had it professionally tuned by a certified mechanic. He did a fantastic job! Now, I have my 351 Windsor in it, which from what I hear, the carb is tuned much the same on a 351W as a 289/302. However, I took the carb off of my 289, pulled the motor, put my 351W in, installed the SAME carb with no modifications, and the carb just won't seem to lean out. It's running WAY too rich!

Somebody please help me!

-TNT

jimmy428

take it to the same mechanic. i messed with my street avenger for a long time and never got it right. imho, get any other holley.

rst08tierney

I had a holley but I'm not a gear head and hated trying to properly tune that puppy so I took the easy way out and bought a performer 600. It was the same price as a california mechanics charge to tune the holly but extreramly simple. I may not get the precision tune as I would with the holley but I can get really close.

longlive289s

ya i just got a street avenger and weiand intake. intake is find but could get the carb to quite tune out....tried to turn the curb idle speed down to no avail. its at my local shop now. i was just sick of it and had been workin on the car for a week straight

cprstreetmachines

When exactly is it rich?

kalli

no such thing as a setting for a 289 will match a 351. vacuum signal might be way different, etc etc etc.
i find it a bit odd that it richens up when stuffed on a 351, unless the 289 had false air, or the PV kicks in too early (way less vacuum signal on 351)
as to CPRs question, how exactly do you know it's too rich as well as when it's too rich
and most importantly, are you sure you have the ignition set correctly? just asking as it was not mentioned.

Kalli

TNTS70STANG

Well, Kalli:

I at least THINK it's running rich. It smells REALLY bad out of the exhaust like a lot of unburned fuel. Also, I'm leaving a very faint cloud of smoke behind me when I accelerate. Also, when I come to a hard stop, the car dies.

I think that I can get the fuel/air mixture right but I don't think that the floats are correct. It says in a manual I bought for Holley Street Avengers that the fuel level in the little float windows should be at the bottom of the window. I can't seem to tune them correctly. The fuel line just won't seem to go lower than the top of the window.

Can somebody give me a good idea how to tune those properly?

THank you guys for the response.

67mustang302

First of all, timing needs to be correct. Make sure fuel pressure is at 6.5psi at idle, set float level, make sure the power valve rating is at least 2" less than idle vacuum, set idle mix screws, set jetting, set accelerator pump. In that order.

kalli

that clearly is a problem. they need to be at bootom of window. do you have that problem front and back? if yes, it might be too much fuel pressure. if it's only in the front, then the float might be hanging. try tapping it. worst case you'll have to take the bowl off and inspect. not hard to do, but tricky the first time. i'm not a fan of those sight windows as you can't really see the fuel line I usually take them out. In any case if you are above the window you're flooding the carb which can cause it to run rich.

Check with 67302m's post. the fuel pressure has to be correct, 6.5 is perfect for a holley