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That does sound like me. I appreciate you sharing the channel David. Thanks

Thank you.

Locking out the distributor with a big cam is usually a good combination when drag racing. I locked out my distributor on my drag car it is bbc and has a holley dominator an it made a world of difference!! But it can cause starting problems, also msd makes a start retard box that will retard the ignition timing while starting. Hope this helps.

The pump circuit is all the same.

I need some information what carb and boosters, jetting and power valve and is this happening under wot or normal driving.

You are very welcome!

You will probaly loose about 500 rpms top end but if you have the room to add a one inch open spacer you want loose any top end. Hope this helps

@holleycarbshowtosadvice40y90 thank you

Your welcome.

I've only got one, i want to keep it. There hard to find.

@holleycarbshowtosadvice40y90 thanks if you run across one let me know

Check both of your accelerator pump arms for any up and down clearence with the throttle closed. if they have any clearence adjust the spring loaded screw and nut just until there is no free play and if it stumbles after that, make sure your accelerator pump nozzles are squirting the minute you open the throttle. If it still has a stumble off idle then remove your carburetor and your front primary squirter, look for a number stamped into it like 25 ,28 or 30 thousandths of a inch what ever size number is on that squirter go up three to five sizes larger, and this should fix your stumble off idle. Hope this helps. Ps removing the carburetor from the engine will prevent accidently droping the check valve down the intake manifold other words if you have the squirter removed and opened the throttle by accident the check weight will shoot up out of the hole and down the intake manifold. That why its best to remove the carb if you have to remove the squirter.

For an off idle stumble always look at the accelerator pump circuit first for malfunctions or out of adjustment. Hope this helps.

Absolutely.. Blp ( Bo laws. Performance ) sells all types of boosters and they instsll them.

Any time you increase the size of the air bleed it will lean that circuit and if you decrease it will richen. Air bleeds work the opposite of fuel jets. Its best to get your jets close and then tune with air bleeds last. Let me know Kevin if i can help you.

@holleycarbshowtosadvice40y90 thank you. I'm getting there

I'm glad i could help. Take care

I need to know where its lean and at what rpm and is it lean under a load or not. All the information you can give me will help.

@holleycarbshowtosadvice40y90 wrong power valve . I got it . Wrong jets. You have really helped me.

Good luck my friend.

Is the mixture screw not bottoming out ?

It is now​@@holleycarbshowtosadvice40y90

10/4

I would use the 4 corner idle circuit mod with a pro street or racing engine with low engine vacuum. With a stock or mild cam i would stay with a 2 corner idle. Hope this helps.

Kevin i have 3 videos that cover how to covert a 2 circuit idle to a 4 circuit part 1-3. But if your engine is stock i dont think this mod will help you. Take care.

Just about any speed shop. Some fastener companies sell 1/8 " cup plugs. Hope this helps

Hsab range from.022 to .036 on the average but this depends on jet size and emulsion. You can not just run the biggest air bleed , it dont work that way. Hope this helps.

Good job

Yes on stock motor .027 hsab and .070 idle is a good starting point .

Ok

I'll try to help you any way i can.

10/4

Randy, iv gone through my carb set up like you did , I have 70 on idle bleeds 27 on the high speed, moved bleeds on the inside of main body, .on the front metering block 27 on all of the fuel and air bleeds 27 on the air emulsion bleeds . Stock 454 with .402 intake and .440 on exhaust . Sound close ?

I need some information on your engine, is running rich and does your engine hsve a racing cam if so i need cam specs and engine vacuum at idle.

Stock 454

402 lift intake and 432 exhaust

Love your info

My carbs with 4 corner idle, i square the bleeds front to rear. If your not running a big cam and running a 2 circuit idle i would leave the rear idle air bleeds stock. On most of my carbs i square jet and also the high speed air bleeds all boils down to your fuel curve. Hope this helps.

@holleycarbshowtosadvice40y90 I'll give it a try, I'm running a stock 454

Remember your air bleeds are proportional to the jet size and idle fuel feed. If your going to run the same size air bleeds front to rear you have to jet properly.

The 4 corner idle is used more in racing engines with big cams in low vacuum conditions. Or drill bypass holes and run a 2 cornrr idle. There is always several ways to skin a cat. Hope this helps.

Some things i'll free hand and others i'll use a drill press or a mill.

The early 4160's came with metering blocks. You have to change to a primary metering block for the rear and modify from there.Hope this helps. Ps some idle circuit holes have to be finished drilled, no biggy. Let me know if you need any help. Also the metering block can be from almost any primary 4150 with a few mods. Take care.

@@holleycarbshowtosadvice40y90 thanks. I have a 600 cfm 4160, but it ran worse than the 465. Never thought about using a primary block to replace the secondary plate. I'll look into it. Thanks.

Will your engine idle down to 800 rpms in neutral and is the mixture screws controling your idle at 800 It should even with a 2 corner idle circuit. Let me know at what rpm the engine will idle smooth on its own. Your cam specs. are fine.

It will idle pretty low for quite a while but then it will idle down and die. I would say at 1000 rpms it will idle forever but I need that 800 rpm idle. I don’t have a tach currently so it’s a guessing game. My vacuum signal also bounces. I just pulled carb off last night to reset all the adjustments and start over. There was a point on my last effort my mixture screws weren’t effective.

Ken that vacuum signal should not be bouncing around with your cam. I think i would check compression first and recheck ignition timing. You can change to a 4 corner idle circuit but may not help. I really don't have enough information, like compression, ignition timing, camshaft installed straight up or advanced. I'll try to help if you can give me some more information on your engine. Take care.

@@holleycarbshowtosadvice40y90 I’m running 18* initial advance and cam was straight up install. I’ll have to check compression as I bought this engine already assembled and don’t have that info. The vacuum signal is stable at a higher idle but when I get it low enough that the cam is loping its bounces from about 8-12”. As soon as it drops it dies.

@@holleycarbshowtosadvice40y90 I might add also that it is really rich at idle. So much so that my eyes burn and water like crazy.

I'm happy i could help. If you ever have a question just ask.

Look at part 3 rebuild of the 4777-2 holley carb. Hope this helps.

Absolutely, its cool to make a change and be able to feel the difference in power. Take care.

I need your carb information and all your information about the concern. If it only happens during cold starts it may be your choke is to rich.

@ from you reminding me about the choke that i totally forgot, i was able to properly reset and adjust the choke. Huge thanks for the reminder cause after doing it, no more white smoke and engine idles super smooth off coldstart and fires up perfectly fine now. Also i have a holley carb 4 pumper just like in this video. Super helpful advice. Anyone who says otherwise is probably dumb.

Thanks bud

Peggy dont plug the hole, we are just moving the idle fuel restrictor from the bottom to the top and we are still using that same passage. The safest way to remove the restrictor is to use a small screw that you can get started in the restrictor hole and then yank it out. You can drill them out but its easy to go to far are not far enough. Hope this helps.

I've never tryed to resize the venturi area, the only company that i know might, would be blp (Bo laws Performance). I don't know for sure but you would have to replace all four boosters and resize the venturi, might cost more than a new main body. Hope this helps.

@@holleycarbshowtosadvice40y90 Your probably right. Easier to get a new main body.

I usually dont run a rear power valve, i just jet up 6 to 8 sizes on the secondaries and use a power valve block off. The reason i block the rear power valve , it is possible to starve the rear power valve circuit under strong performance cars thats why we run jet extenisons in the rear and the power valve circuit sets above the jets. With all that being said you can drill the rear power valve circuit. Hope this helps. Thanks Matt.

Ted are you near jacksonville florida?

thanks for responding, i’m in Canada. i changed both metering blocks and all good now. what’s weird is i checked every passage and they were all clear.

Somewhere along the line it must of had a restriction in the idle circuit, its always good to have extra parts. Take care.

Thank you my friend.

Your welcome.

Yes anytime this afternoon after 4:30 pm

Bigblockchevyman1121@gmail.com

When you hit your lean spot can you aceelerate more and drive through it. One other thing you say its worse in 2nd and 3rd gear, does it happen in 4th gear, also send me your list # off your carb and i'll take a shot at it, there is so things that can cause these types of problems. Also what rpm is the lean spot.

Thank you for responding. The list number is 90670. It’s a 4 speed with low 1st 2nd and 3rd it happens every time in second and third And in first if the load is high and never in low gear. I can’t drive through it at all it leans out for as long as I hold the throttle in that position. there has been times I pumped the pedal in hopes that the accelerator pump would help but no change. Rpm is 1000-1500 in 2nd a little higher maybe up to 1700 in 3rd once past the lean spot she’s great. I have tried power valves from 2.5 through 6.5 and seems a bit better on the 6.5 and have a 7.5 and an 8.5 coming to try. Thank you !

There's alot to look at , this could be a carburetor problem or fuel supply issue, or carb not venting properly . I believe i would start at fuel supply first, with the ignition disabled remove fuel line and check fuel delivery electric or manual fuel pump should have a solid stream around 3 inches long and manual pulsing 3inches. Check your carb for venting restricting , drain the fuel bowl and check for water. Also defective ignition coil can cause this. If i had a spare carb or one you could borrow i would try that first. I've seen so many crazy things an engine back fire and damage the carb float and it hang up restricting the fuel to the bowl. And there is always a chance of trash in the main well floating around between the jet and the booster with no way to escape. I know this is a lot to do if it was me i would check fuel flow first if ok then i woul try and substitute a carb that way you will know which way to go from there. Hope this helps.

@@holleycarbshowtosadvice40y90thank you again for responding. Fuel supply and ignition are all new and functioning properly. It will rev and pull under load at 6-7k rpm all day long once past the lean spot. It runs fine with the quadrajet on it but I live off road in the mountains and this truck spends 90% of the time on very uneven terrain. That’s why I wanted to try this truck avenger carb. The vents are clear I did verify that yesterday. When I drilled and tapped the idle Fuel restrictions which helped air fuel ratio. I have everything dialed in to 12.5-13.5 on my afr guage. But the lean spot. I noticed what seams to be check valves or balls in the main wells. They clunk when I flip the block upside down and can see them flopping around. Are these normally in Holley metering blocks? If not I wonder if that’s one way they keep the carb from flooding on steep inclines. And could that be causing the problem. Thank you again for your time.

Thanks

I'm glad i could help. Thanks

I guess it matters which bleeds , factory or if your changing from press in bleeds to threaded bleeds, the small hex threaded cups that are from companies like fastenal. BLP sells tapered bleeds which is ( Bolaws performance). I think ebay may sell um. Companies that sell fasteners usually sells cup plugs Hope this helps.

The small screw in brass hex headed cup plugs are available through several companies, (Fastenal )is one of many. Check around on google i cant remember where i bought last bunch, you can usually get a better deal in bulk. I believe amazon sells some tapered bleeds. Hope this helps

Anytime

An engine with a racing cam , creates low vacuum so usually its best to set the idle circuit up completely, now with out a racing cam you could play with the bleeds.hope this helps.