460 is running rich on Edelbrock 1411

[viven44]

My 78 Bronco with the 460 is running rich. I am using a new Edelbrock 1411 (750CFM), with a frame mounted Edelbrock 17301 fuel pump that puts out between 4-7PSI. No return line as I am running the stock tank.

Symptoms
-- loss in power with sudden throttle application or get up and go... I just don't have the oomph (with Big Blue 2WD as reference using the same Edelbrock 1411). I had assumed this was TC/Transmission related but I'm starting to suspect A/F ratio.
-- black soot in tail pipe
-- horrendous gas mileage... even for a 460 (this is probably what got me to look into this)
-- Idle fuel pressure over 6PSI... but then when warm this number comes down. I know this is gauge related as I've seen gauges with the internal fluid do this when warm (Big Blue 2WD's gauge is at 0 when fully warm ).

Questions
-- I'm going to install a fuel pressure regulator... Can I set it at 4.5 ~ 5PSI? Big Blue 2WD is at 4.5PSI using the stock 460 hot fuel system and does well.
-- Is my assessment correct that I am running rich because the fuel pressure is a bit higher than it needs to be ? I just can't understand why that would as the float would limit the fuel entering the carburetor correct ? I have no leaks or other indications that the pressure is too high.
-- Do I need to change the stock metering, etc ? The carburetor is literally brand new with approx. 250 miles on it.

[Gary Lewis]

Do you have two Edelbrocks?  If so, swap them?

As for pressure, 6 psi is probably too high.  What happens is that you set the float level but when the pressure comes up it lifts the needle and tends to raise the fuel level, which makes the AFR a bit richer.  But that usually shows up at idle, not WOT.

So yes, you can set the regulator at 4.5, which is where I like to run them on an Eddy.  It'll be plenty of pressure but not raise the float any.

As for the metering, I wouldn't change it until you get the fuel pressure where it should be.

Do you know that the secondaries are opening?  What happens when they do?

[viven44]

Good question on the secondaries. The power increase from secondaries opening has been something I have never noticed. In this truck, I can clearly tell when they do as there is immediate boost in power. Before I installed the carb, I could tell (since bottom is visible) also that approx 60 percent throttle the secondaries open.

When I rev the truck when parked I can see excess smoke/fuel out the tailpipe. That was my cue to the WOT aspect. I was wondering if excess pressure combined with spikes in fuel pressure during WOT might do some funny stuff.

I wish I had a spare carburetor, but I don't.

[viven44]

I just climbed up there and verified the secondaries are indeed opening... and they are all the way.

Now I did find that for some reason the carburetor had the accelerator pump setting at the very top (Richest). I would have thought the carburetor would have come in the middle spot from the factory! This was a new carb I bought from summit. I set it in the middle now... I feel it is doing better. Maybe a placebo effect :)

Will install the "Holley" fuel pressure regulator when it arrives later this week.

[ArdWrknTrk]

I definitely have a 650 AVS in Wilton. I just haven't been there in 9 months....

I'm going to make a valiant attempt at retrieving my tools and will let you know if I still have it.
It worked fine on my truck, with minor mods: like a cam, Performer intake and big exhaust.
It should be fine in a Bronco (if a little under-tuned, given how heavy my P/U is..)

[viven44]

Jim, thank you!! but don't worry about that carb..

I think the carb I have is probably just fine, if not.... still under warranty . I'll update after installing the fuel pressure regulator!!

[Gary Lewis]

If the carb is, for some reason, jetted rich and you hit it with a full accelerator pump shot it'll fall on its face.  And any extra fuel pressure will exacerbate the problem.  So backing off to the middle is a good idea, and installing the fuel pressure regulator should be next.

And you should check the float setting to make sure it isn't too high out of the box.  I've seen a lot of poorly-adjusted brand new carbs.

[viven44]

Thanks! Float check requires the air horn to be removed if I'm not mistaken. I have never had to adjust the floats before on an Edelbrock.

I'll install the regulator and also keep an eye on the vents to see if I see fuel coming out. I'll call Edelbrock just to be sure on why the accelerator pump setting was not set at the factory defaults. Just in case....

I think on a 302 especially a carb or accelerator pump that is running rich may be obvious but a 460 will drink all the fuel it can get so I'm a bit late here paying attention to this... even now it runs great. Vac is better than 21 inches.... just horrendous gas mileage and a lot of fumes when I rev it while parked

[ArdWrknTrk]

Not ALL the fuel a 460 can get!  

When I first bought the 08457-S that I gave to George for their Ranchero, one of the butterfly screws on the secondary was not tight and hung up the float.
Holley demanded their QC was 100%!  🧐

It hydro locked, naturally....
With a mechanical pump, no fuel at all is moving unless the cam is turning.
But the higher the R's the more volume you can get.
The pump itself has a return line....

[Gary Lewis]

ArdWrknTrk wrote

Not ALL the fuel a 460 can get!  

When I first bought the 08457-S that I gave to George for their Ranchero, one of the butterfly screws on the secondary was not tight and hung up the float.
Holley demanded their QC was 100%!  🧐

It hydro locked, naturally....
With a mechanical pump, no fuel at all is moving unless the cam is turning.
But the higher the R's the more volume you can get.
The pump itself has a return line....

Amen, brother!  When I got Big Blue  had bypassed the safeties on the electric fuel pump.  Someone turned the key on and hydrolocked the engine.  I pulled the drain plug and got 6 quarts of oil and 7 quarts of gas.  And each cylinder was FULL as well.

But yes, pull the air horn on the Eddy and you can set the float levels.  Specs are in this document: https://www.edelbrock.com/media/wysiwyg/documents/carb-owners-manual.pdf

[viven44]

I called Edelbrock and according to the carburetor should never be in the “Richest” setting on the accelerator pump from factory. And based on the other things I described they had concerns of it being tampered with possibly. They said I should reach out to summit and just warranty it for a new one. Well summit just took it back as it was within the return period…

I’ll probably just buy another 1411 unless there should be another that would do better for a 460.

[ArdWrknTrk]

I was really happy with the 650 AVS. (I think it's a better carb, than any AFB)

[Gary Lewis]

The AVS is the better of the two carbs. And 650 is enough for a 460. I swapped from a 750 Eddy to a 600 and could only tell the difference above 4000 RPM.  You might consider buying Jim’s AVS.

(I had that almost typed while at Janey’s therapy and then started talking with a guy named Bill. He’s an 88 year old hotrodder with a 64 Chevelle with a 544 in it running methanol. We talked AFBs, AVSs, WCFBs, QJets, and even Holleys - and his opinion on the later is the same as mine.  And he agrees he’d put the 650 AVS on the 460.)

[ArdWrknTrk]

I'd give it away (as I did the Holley) just to pay it forward.
I certainly don't need it where I'm going...

But all that hinges on getting to Wilton, and if any of my stuff still exists.
RN I'm trying to fix all the crap wrong with the Altima for my nephew, and getting my truck reliable for travel.

Please stay tuned! I'm not sure where this is going....  🥴

[viven44]

Summit just called me and told me my carb is outside the 90 day return but would consider an exchange since I’m having warranty issues. I’ll be going into store later, let me see if I can charm them into selling me a 650AVS instead

It has vacuum secondaries right ? I assume that’s what the VS in AVS stands for. I’ve seen vacuum secondaries are better for a truck but not sure why.

[ArdWrknTrk]

88 years old w/ a 544 running meth?
God bless him!  🙏

I don't want to make 65, but it seems he's found some excitement in his life!  

[Gary Lewis]

AVS = Air Valve Secondaries.

An Aluminum Four Barrel (AFB/Edelbrock Performer) has adjustable secondaries - you disassemble the WHOLE carb and either grind weight off the arm or weld weight onto it to get the secondaries to open sooner/later.

On an AVS you hold the adjustment screw so it doesn't move and loosen the set screw and either loosen/tighten the adjustment screw to open soon/later.  You'll usually have to pull the air cleaner but nothing else to do that job.

Keep adjusting until the secondaries open just a bit too soon and you bog, and then tighten it up slightly and you are adjusted perfectly for the elevation and temp where you are running.

[Gary Lewis]

ArdWrknTrk wrote

88 years old w/ a 544 running meth?
God bless him!  🙏

I don't want to make 65, but it seems he's found some excitement in his life!  

We had a wonderful conversation!  It started with him saying to someone else "Have you been back to Ark City?"  I told him that was my home town.  He said he used to run at the drag strip there.  I said you mean the touch & go strip west of town?  I saw Art Arfons run there.

An hour later we'd discussed Buick 300's with aluminum heads and Super Turbine 300 transmissions with the switch-the-pitch feature, Buick 455's, Motorcraft 4100's, etc.  I'd start into something and he'd chime in with a detail that proved he knows what he's talking about.  Or vice versa.

That's why I got three lines typed earlier and didn't finish until we got home.  

[ArdWrknTrk]

You never know where you're going to bump into a confederate..

[Gary Lewis]

Yep, I didn't expect it at the "gym" where Janey is taking therapy.  But some of these people have been coming there for 20+ years and know everyone and their families.  The first day there I didn't fit in - or so I thought.  But now I do.