I need some help. Just got my freshly rebuilt 327 fired up and broke in. I am running a new out of the box 1406 Edelbrock 1406 with electric choke on a C4B vintage Edelbrock intake with a phenalic 1" carb spacer. . It is idling around 2200 to 2400 RPM. Even after driving it a few miles (so the choke should be warmed up). I adjusted the idle all the way out to where it no longer moves the throttle arm. I talked to a tech at Edelbrock (after waiting 10 minutes) and he said to adjust the fast idle. I have adusted it to where it will not touch anything. He also suggesting turning the fuel/air adjustments in 1/4 turn. no impact I called a second time (and waiting another 10 minutes) and they said the 'L' shaped rod that impacts the secondaries might need to be spread open some. He also asked if I checked for air leaks between the carb and intake. I said I did initially by spraying some windex but did not notice any. The car is now at the muffler shop but upon return I will check again for air leaks (need to get some start fluid). I thought i would check on here to see if anyone else has run into this and how you fixed it or what else i should be looking for.
I would pull it off and check for marks on the gasket for air leaks. Mine was whistling and a simple gasket change got rid of it. while its off you can check to see if the secondary's are closeing all the way. Also if you use a screw driver to turn the idle mixture screws in and turn them in too tight you can bust the casting out the back. you can ask me how i know because my buddy did it to his.
might seem obvious, but remove your throttle linkage or cable and see if that doesn't change things - also kick down link or cable. You might be surprised even when you swear that can't be it.
Windex???? isn't that a window cleaner??? What would you use that for?? A leaking gasket ****s in, not blows bubbles outwards. Use WD40 and see if the rpm surges up a bit. Looks for obvious leaks, like a vacuum cap leaking or missing. Or a hole in a vacuum pipe.
morris, Idid not say I was smart for using windex but it was what I had late last night, just wanted to see if I say any creeping/ ****ing of fluid. I bought a can of wd40 on the way home from the muffler shop to check it when it gets home. I am 99% sure it is returning all the way. (but will remove the linkage and double check.) I have all the ports except one blocked off (one that is not is going to distributor).
I've run into this a few times, looks like everyone has it covered: Check throttle linkage to make sure it is allowing it to return all the way, check for any vac leaks, make sure spring is strong enough to return all the way, double check carb linkages not hitting anything, and make sure the trans kickdown (if you have one) isn't stopping it. Double check your timing too, timing can affect idle, although it shouldn't keep you from setting it. If all is loose and no vac leaks, you should be able to adjust it so low the engine will die (depending on engine setup of course).
An update. Got the call the exhaust was finished and went down to get it. Hit the switch and the car fired right up and it was now idling at about 1000 rpm lower (now at about 1600 rpm) than it was when I drove it down. (the car only had very short Sanderson headers.. shorties). I do not know how adding exhaust made the difference. After getting it home, I removed the air cleaner and found the center port on the front of the carb base had blown off its black plug/ cover, so I reinstalled and used a Zip tie to keep it on. I removed the throttle cable and double checked it was all the way out (it is a Lokar cable, so I figured it was fine as I had a little movement in the cable). I sprayed WD40 at the base and did not hear any changes. I readjusted the High Idle (so it again touches) and was able to get a little more adjustment out of the idle. It is now idling at about 900-1000 rpm in neutral Tomorrrow I am going to borrow a timing light and double check that. I still can not idle it down to get it to stall/ die.
I vaguely recall the secondaries have a screw adjustment that you can only see/access from underneath the carb. It cracks them open a touch to give smoother idling, or some such thing. Worth having a look. That might just be Holleys though... You could drop a few drops of thick oil onto the secondaries to see if they are leaking, as it'll seal the edges.
Did you plug the threaded hole in the BACK of the carb body? When I first fired up my car it was idling really high and it took me a minute or two to realize there was an open port in the back of the carb (for power brakes, I presume) that I wasn't using. Put the plug in and it's been 100% exactly like it's supposed to be ever since - idles at 650 rpm, and I can easily stall the car by adjusting the idle screw out a bit or adjusting the mixture screws too far in or out. The car WILL run and drive with that port unplugged, it just won't act like it should.
If the throttles are closed (speed adjustment screw backed right out) and you can't kill it, it's getting air from somewhere. Keep checking, you will find it.
Buddy of mine had a two 4 setup ( Edelbbrock). Couldn't get it to idle down. Tried all the usual stuff, no help. Turned out it was a defective carb. They swapped us another one and it worked fine.
I just went thru this myself. You've got an air leak somewhere. Make sure you plug EVERY vacuum fitting and test. Keep at it. You'll find it, but it can drive a person nuts.
Got it all working great now. never found any leaks, it now idles at 600 to 650 in park and drops down to around 500 in drive. there must have been some debris in the carb as the longer it ran the better it got.. Put a timing light on it and found it was on the rich side, so adjusted it.. reset the idle and that was it..
Bingo, make sure the ****erflies are closing all the way. If not then some carb linkage is holding them open or the ****erflies are not centered on the shaft. Lippy
From the start my last Edelbrock g***ed up the motor and ran rough, killed a set of plugs. Then I noticed the little letter inside the packaging, telling me to check the needle valve wasn't dirty (on a brand new carb)... I pulled it apart, checked it and it had a chunk of polystyrene in it and was chugalluging fuel through continuously.
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