C2 Replacement Holley-wont clear to idle

[John P.]

Re: C2 Replacement Holley-wont clear to idle

Very interesting. What were you using as lubricant on the pad? I take it you did not replace the weights?

[Bill B.]

Re: C2 Replacement Holley-wont clear to idle

I used powdered graphite SPARINGLY - I had a Q-Tip that I had rubbed powdered graphite in and carefully rubbed onto the contact pad buttons and then polished with a cloth. (I first used crocus cloth to lightly polish the button pads before applying the graphite).

Ditto with the weights - removed them from the pole piece and polished all the contact areas of the weight, then rubbed with the graphite and polished with a dry cloth.

Made sure the weight bearing area was also clean and carefully lubed.

Highly recommend a vacuum or compressed air to use in the distributor cavity area and the separate pieces to make sure everything is clean after graphite.

One MUST be careful with the graphite - it is an electrical conductor and you DO NOT want any loose granules floating around in the distributor area.

If it still seems to hang up when manipulating by hand, then the pole piece and main shaft interface area may be the issue where the excessive friction may be occurring. Of course, when you do the mechanical manipulation test, make sure that the distributor is in a location where the lobes are not contacting the point block, otherwise you may get a false negative or positive of hang-up. Similar if TI in the area where the magnetic force is present.

[Duke W.]

Re: C2 Replacement Holley-wont clear to idle

I don't use any kind of lubricant on the centrifugal mechanism, unless you consider WD-40 a lubricant, but the reason I rub the weights and spray the springs with WD-40 is to prevent corrosion. These parts are hardened, lightly loaded and just need to be clean.

I've seen distributors where Bubba applied gooey, sticky grease to the mechanism with a soup ladle. All that does is clog up the mechanism, preventing it from working properly.

Duke

[Owen L.]

Re: C2 Replacement Holley-wont clear to idle

I cannot tell how to loosen and reposition the primary or secondary flappers Holley support offered nothing Makes sense to me that mechanism is not quite functioning properly but cannot tell I was told not to lube anything

It's a simple fix to make sure the throttle blades are centered in the bores but you do have to remove the carb to do it. Once removed, disconnect the vacuum secondary rod from the secondary shaft. I believe that is the only linkage connection between the base and main body.
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Flip the carb over and remove the 6 or 8 screws securing the base and separate it from the main housing.
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Loosen the screws that secure the blades (disks) to their shafts. These are swaged screws that have the thread ends smushed to keep them from backing out and falling into the engine. Only unscrew them enough to allow the disk to move around on the shaft; if you do more than that, you risk snapping the heads off. Work the shaft mechanisms so the blades find their centers in the bores and tighten the screws. Check for free movement from full open to full closed. Reassemble.

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[John P.]

Re: C2 Replacement Holley-wont clear to idle

typically i have a high idle that wont adjust down easily. At times after stopping for gas etc, even with warm engine, idle will be too high, say 1100,
but Have to pump the accelerator hard and repeatedly to get 750. And it doesn't always go back to 750

[John P.]

Re: C2 Replacement Holley-wont clear to idle

typically i have a high idle that wont adjust down easily. At times after stopping for gas etc, even with warm engine, idle will be too high, say 1100,
but Have to pump the accelerator hard and repeatedly to get 750. And it doesn't always go back to 750

[David H.]

Re: C2 Replacement Holley-wont clear to idle

typically i have a high idle that wont adjust down easily. At times after stopping for gas etc, even with warm engine, idle will be too high, say 1100,
but Have to pump the accelerator hard and repeatedly to get 750. And it doesn't always go back to 750

John

High idle, that won't adjust down, can be caused by your carburetors transition "off idle" or "transfer" circuits. These circuits normally add fuel during that transition from idle rpm to rpm requiring main jet supply.

If these circuits are exposed at idle, then that extra fuel results in increased rpm that won't adjust out with your normal idle speed adjustment screw.

Several potential causes for these transition circuits to be exposed (supplying fuel) at idle. Misalignment of throttle plates could cause a binding not allowing throttle to close - exposing transition circuits. Some high lift cams can generate similar symptoms.

A YouTube search for "Holley off idle transfer circuits high lift cam" should give you lots of video material on how these circuits work/problems.

You might visually your carburetor as a check.

Dave

Added: Does your car idle rich? Do your air/fuel mixture screws act as expected? i.e. if screwed all the way in, does your engine stumble/quit as expected or does this have little/no effect? If so (mix screwed in), that fuel at idle is being added via transfer (off idle) circuit.



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[John P.]

Re: C2 Replacement Holley-wont clear to idle

the mixture screws work as expected. The car runs very well after I did tuneup a while back, very much by the manual.

The idle seems to be the only major issue.

[Owen L.]

Re: C2 Replacement Holley-wont clear to idle

I discovered my misaligned throttle plates by unscrewing the curb idle screw all the way so there was a good 1/8" or more gap between the screw end and the linkage. The car still wouldn't idle down and it was a bit inconsistent on where the idle fell: sometimes it was ~1000 rpm, sometimes ~850, sometimes ~1100, hardly ever down to the 600 range where it should be. Upon taking it apart I found the issue that my plates were scraping the bore and closing at different places depending on how quick the accelerator snap back was.

[Leif A.]

Re: C2 Replacement Holley-wont clear to idle

Owen,
Excellent show and tell. For those of us who like/need pictures. I'm a visual learner myself so your post was most informative and easy to follow. Thank you.

[John P.]

Re: C2 Replacement Holley-wont clear to idle

Very helpful Was that on a replacement Holley?

[John P.]

Re: C2 Replacement Holley-wont clear to idle

So even without the idle problem, should I change out advance springs and/ or weights to give better performance overall? If so which ones/vendor to use?

[Gary B.]

[Owen L.]

Re: C2 Replacement Holley-wont clear to idle

Very helpful Was that on a replacement Holley?

So the pics are stolen from the internet with my added arrows and text.
My misalignment problem however was with my very own re-released Holley 3811 for my '67 390hp; I believe I bought it 10-15 years ago but just recently got fed up enough to tear it down to address other issues.

[John P.]

Re: C2 Replacement Holley-wont clear to idle

Well it appears that the idle has stabilized with new generic Advance Auto throttle springs.

New Spring on the way from Zip we shall see how that works .

Thanks to all who responded.