setting a Holley 1946

  • Thread starter Thread starter Anonymous
  • Start date Start date
sargentrs":36ica8yv said:
So I'm turning the wrong screw. My TSP is removed and the screw I should be turning is the one on the passenger side, toward the rear of the carb. It's actually a 3/8 or 5/16 hex head bolt, no slots for a screwdriver.
That didn't sound right to me, cause every 1946 I've seen has a hex head screw with a slot for a screwdriver.
So I took a picture and circled the curb idle screw:

The screw goes through a hole in the casting.
You may have been looking at the transmission kickdown adjustment screw.
You may have to loosen off the air cleaner to get to it.
 
This is the version I've got, and it blocks the pop-ups.

ieabouttx4.jpg


I also use ZoneAlarm and SpyBot's "Immunise" feature - maybe that helps, too?
 
Alright... check to make sure that the fast idle screw isn't too far in, because then you'll pass the idle, and you won't be able to tune the mixture for anything. Turn on the blower fan and turn on your lights, let it warm up. Put it in drive. What's the RPM there? Turn the fast idle out as far as you can get it without it dying, and then adjust the mixture screw. I think with the mixture screw it's turn in for slower idle, turn out for speeding up (opposite of fast idle, right?). Once you get the mixture set with a vacuum gauge and everything looks good there, set the RPMs with the fast idle. You should be in good shape after that. Double check your timing and TDC and that's all I got for ya right now as I'm tired as hell. Hopefully this helps!
 
65Stang200":3kwt8bcm said:
Alright... check to make sure that the fast idle screw isn't too far in, because then you'll pass the idle, and you won't be able to tune the mixture for anything. Turn on the blower fan and turn on your lights, let it warm up. Put it in drive. What's the RPM there? Turn the fast idle out as far as you can get it without it dying, and then adjust the mixture screw. I think with the mixture screw it's turn in for slower idle, turn out for speeding up (opposite of fast idle, right?). Once you get the mixture set with a vacuum gauge and everything looks good there, set the RPMs with the fast idle. You should be in good shape after that. Double check your timing and TDC and that's all I got for ya right now as I'm tired as hell. Hopefully this helps!
hmmm, that doesn't sound quite right to me.... :?
The fast idle is only for cold starts and choke-on conditions, and should only be set on a cold engine. Mine starts at 1200rpm cold and as the engine warms it speeds up to 2000rpm. Then kick the throttle, which releases the fast idle and the choke.
The curb idle screw is the one for a warm engine, and is the one circled in the pic.
I find it's a bit of a dance going between the mix screw, the curb idle screw and the distributor timing to get it tuned.
 
JackFish":3ii5iu5r said:
Mine starts at 1200rpm cold and as the engine warms it speeds up to 2000rpm. Then kick the throttle, which releases the fast idle and the choke.

I have never liked mine to be adjusted that high.
 
Actually, the fast idle cam has a couple of steps in it, and the lower step accomodates a lower rpm setting.
 
OK, I've got the right screw now, thanks to JackFish and his pic. I was looking at the transmission kickdown adjustment screw...DUH! So I idled it up a tad to around 900 in neutral and it drops down to 650 in gear. Acceptable but I don't feel it's right yet. She shouldn't have to idle that fast in park. Now, I've got the choke wired back up now but she's not working. I know about the fast idle cam steps and I've twisted the choke body around so the butterfly closes to the set spec. However, the fast idle cam just kinda flops around with no real set place and the fast idle adjustment screw isn't contacting it, even when screwed all the way in. Can somebody advise me on how to adjust the fast idle cam?
 
If the choke body (or choke cap) is adjusted properly, it should have enough "spring" to it to push the fast idle cam downward (when the engine is cold) when you press the accelerator. (BTW, are you pressing the accelerator down once when it's cold? This is what activates the choke mechanisms. When the choke is off or hasn't been activated by pressing the accelerator before starting the engine, the fast idle cam will flop around like you describe.)

Here's how the Haynes manual recommends adjusting the fast idle on the 1946:

"With the choke off and the engine running at normal operating temperature, raise the speed of the engine to 2500 rpm for 15 seconds. Place the fast idle lever [fast idle adjustment screw] on the specified step of the fast idle cam.

Allow the engine speed to stabilize and measure the engine speed (rpm). Depending upon the engine and the state of tune, it may require anywhere from 15 seconds to 2 minutes for the engine speed (rpm) to stabilize.

Repeat the above step three times to ensure accuracy.

Adjust the fast idle screw as necessary.

Repeat the rpm check if an adjustment has been made."
 
So that's...adjust the fast idle screw WHILE the engine is running at 2500 rpm? Can I turn the curb idle screw in to maintain that while I adjust or do you recommend having someone hold the gas pedal down? Then readjust the curb idle back down to normal?
 
I don't like the Haynes procedure, but that's the only manual I could find at the time. I have a Chilton in the trunk of the Falcon, but I'm not near it now. It has the exact specs for setting it, and I'll post them tomorrow.

In the meantime, I found this step-by-step procedure for the 1946 fast idle adjustment on AutoZone's website. It makes much more sense, and this is the one I would follow:

"Be sure that the curb idle speed and idle mixture are set to specification before adjusting the fast idle speed.

1. Place the transmission in Neutral or Park and bring the engine to normal operating temperature.

2. Turn off the ignition. If so equipped, set the A/C selector to the Off position.

3. Disconnect the vacuum hose at the EGR valve and plug the hose.

4. If so equipped, disconnect the wire to the electric PVS.

5. Place the fast idle adjusting screw on the specified step of the fast idle cam.

6. Connect a suitable tachometer.

7. Start the engine without touching the accelerator pedal.

8. Adjust the fast idle speed to specification by turning the adjusting screw.

9. Rev the engine momentarily to allow the engine to return to idle and turn off the ignition.

10. Disconnect and remove the tachometer.

11. Remove the plug from the EGR vacuum hose and reconnect the hose.

12. If so equipped, reconnect the wire to the electric PVS.

13. Install the air cleaner assembly, if no further adjustments are required at this time."

Again, I will post the specs - which step on the cam, rpm setting - for this tomorrow when I get my other manual.

(There is also an adjustment for the position of the fast idle cam by bending the connecting rod between the cam and the choke body. However, you shouldn't have to adjust this if everything was working before. My 1946 was a reman from AutoZone, so I had to end up adjusting this to get the choke plate in the correct position.)
 
3. Disconnect the vacuum hose at the EGR valve and plug the hose.
Scrapped the pollution control stuff.

4. If so equipped, disconnect the wire to the electric PVS.
What's a PVS?

6. Connect a suitable tachometer.
Is the dash tach OK?
 
sargentrs":u335r44n said:
So that's...adjust the fast idle screw WHILE the engine is running at 2500 rpm? Can I turn the curb idle screw in to maintain that while I adjust or do you recommend having someone hold the gas pedal down? Then readjust the curb idle back down to normal?

:?: :? :?:
How can you adjust the curb idle down to normal if you don't have it idleing down as you adjust it............. I mean how can you tell its normal?? :shock:
You adjust the fast idle to spec.. I don't think 2500 is spec. for the fast idle.. You let the fast idle come down as you adjust it to spec. while the motor is cold. If your think as in adjusting the carb while you brakeing in the motor (I'm guessing thats why the 2500 rpm.) you can't you have to brake it in first then adjujst the carb.
tim
 
He's referring to my earlier post with the fast idle adjustment instructions from the Haynes manual - which I despise. I am STILL looking for my Chiltons manual. It has an easier-to-follow procedure and lists the adjustment specifications.

So far, the second procedure for fast idle adjustment (which is specifically for the Holley 1946) from AutoZone that I posted is the best I've found (other than Chiltons). It specifies that the fast idle adjustment be made while the engine is at normal operating temperature.

PVS = Ported Vacuum Switch. Since you've scrapped the emissions gadgets, this step most likely won't apply to you. I would just skip it - wouldn't make much of a difference either way.

Your dash tach should be sufficient if it is accurate. It's been my experience with this carb that you set everything to spec and usually have to tweak it a little. I've personally never used a tach to set the fast idle. I've just adjusted it to the rpm that I thought sounded "right".
 
JackFish":rz7u69cw said:
sargentrs":rz7u69cw said:
So I'm turning the wrong screw. My TSP is removed and the screw I should be turning is the one on the passenger side, toward the rear of the carb. It's actually a 3/8 or 5/16 hex head bolt, no slots for a screwdriver.
That didn't sound right to me, cause every 1946 I've seen has a hex head screw with a slot for a screwdriver.
So I took a picture and circled the curb idle screw:

The screw goes through a hole in the casting.
You may have been looking at the transmission kickdown adjustment screw.
You may have to loosen off the air cleaner to get to it.
To correct myself, the screw I called the tranny kickdown is actually the idle speed screw for the TSP :oops:
 
Back
Top