Holley Carb Off Idle Stumble FIX

In this video, we explain the most common fixes for a off idle stumble on your Holley Carburetor.

[@bertramlrezenet9311]

Hello Randy, another great video. I thought I would mention, we called the umbrella type inlet check valve is an elastomer valve. Keep up the good work!

[@holleycarbshowtosadvice40y90]

Absolutely.

[@HeadFlowInc]

Acc. Pump adjustment should be .015”-.018” at WOT to avoid damage to the pump diaphragm. 👍

[@holleycarbshowtosadvice40y90]

Thanks for watching

[@HeadFlowInc]

@@holleycarbshowtosadvice40y90 Accelerator pump adjustment shared years ago on the PY forums by Tom Vaught long time Holley Engineer. 👍

[@TheSaxon25]

Lets go Randy! Great video as always. I'm passing on the knowledge to a couple young bloods to get their rigs down the road. Always pay it forward. Thanks for the knowledge 🍻🍻

[@holleycarbshowtosadvice40y90]

Thanks Ssxon I appreciate it. Take care brother

[@Adrenacyde]

Glad to see a new video out Randy and Mr' Cameraman. I just picked up a new to me 850 CFM Holley 4781. Was planning on using AED 6580 metering blocks. Do I need two, or just one for the Primary side?

[@holleycarbshowtosadvice40y90]

AED makes great products, this comes down to personal preference how far you won't to modify it, I believe you could make good either way. I do believe the primaries are most important. Hope this helps.

[@327365hp]

Good stuff Randy, thank you!

[@holleycarbshowtosadvice40y90]

Thanks

[@danielesilvaggi]

Thank you for the videos.

[@holleycarbshowtosadvice40y90]

Glad to help.

[@oldmanintheshopbuiltnotbou8726]

great info

[@holleycarbshowtosadvice40y90]

Thanks .

[@Bereft777]

measuring the clearance on that pump check was something else. i confirmed it sealing by filling it up with fuel and ensuring zero bypass ..on the discharge check too

[@holleycarbshowtosadvice40y90]

Jack you are right on point and well thought out. Take care.

[@L72Belair]

thanks

[@holleycarbshowtosadvice40y90]

Your welcome

[@direct998]

The shot from the shooters could also put too much fuel too quickly causing the engine to stall . Great video .

[@holleycarbshowtosadvice40y90]

Thanks for watching

[@LENSO_CHEVY_LT1]

Excellent vid once again. Have you got a vid on pump cam selection? I generally start with the red cam but sometimes when changing them its hard to tell the difference what with so many other things happening at once

[@holleycarbshowtosadvice40y90]

I know what your saying, aggressiveness and dwell time can get confusing. We'll do a video.

[@RobertSiwik1968]

Great video!

[@holleycarbshowtosadvice40y90]

Thank you

[@kfacpa]

Great video, thank you. I have the opposite issue... an unexpected acceleration just as I'm pushing down on the accelerator... and with 640 ft/lb torque, it's kinda neck snapping.... any thoughts?

[@holleycarbshowtosadvice40y90]

Just don't mash the gas on that beast. Lol

[@kfacpa]

@@holleycarbshowtosadvice40y90 🤣

[@Youtubecensoredmyusername]

@@holleycarbshowtosadvice40y90😮

[@theredwedge9446]

Randy, I have a Holley 750 vacuum secondary with an HP body, 82750SA. The carb runs great. However, I get an initial AFR lean spike and quick bog at the onset of the secondaries opening. Once they open, the car hauls. It came with the plain spring. Going to a stiffer spring makes the bog worse an last longer. Going to a lighter spring doesn’t help. Idle, transition, accelerator circuit, primary circuit, and WOT are perfect. Any ideas?

[@holleycarbshowtosadvice40y90]

Things that can cause these symtoms, secondary coming in to fast or jetting to lean, float level to low . Check your primary pump cam, see if its a pink cam the pink cam carries a longer duration pump shot may help.

[@nwmod39]

I would start with making sure your float level is where it should be and then upping the secondary jetting a bit since there is no secondary accel pump nozzle. Pending on how far open the primary blades are and what your idle is set at.... you could possibly afford to close your primary blades a touch and then open your secondary blades a touch to get more into the secondary transfer slots.

[@Baker504]

Good video

[@holleycarbshowtosadvice40y90]

Thanks

[@robertjohnson-454]

A little constructive criticism. You don’t show how to adjust it so you’ve just unincluded half your audience. Also since so many make this mistake you must ALWAYS make sure that the lighting and angle are good so that people can see exactly what you are doing.

[@holleycarbshowtosadvice40y90]

We do the best we can, and try to improve. If you have a problem you can always leave me a message. Other than that if your not happy there's always other channels out there. Hope this helps