edelbrock problems

[86shortchevy]

I have a 327 with a holley street dominator intake and edelbrock 1406 carb that i converted to manual choke. The problem is that it will not idle right unless i have the choke pulled, it sounds like a tractor without the choke (it doesn't lope like it should). I have tried just about everything as far as the mixture screws go, I started at 1 1/2 turns out, and it wouldnt even stay running without the choke pulled, i went all the way to around 4 turns out and it still did the same thing. at 4 turns out, it would atleast idle without the choke, but still sounded like crap. To me it sounds like its lean.. but my plugs say rich. Could something in there be clogged up or something?? it is a used carb but i completely rebuilt it.

[85Bowtie]

Well....you're in TN and I don't know about you but it's been pretty damn cold here...is your truck warmed up when you're having these problems?

You don't just start turning those screws without having a vaccum gauge hooked up to it. With the engine warmed up, hook a vaccum gauge into your manifold vaccum port on the front of the carb then turn one screw in or out until you have the highest vaccum reading. Then repeat with the other screw. On Edelbrocks, you do not need to have both screws turned out equal amounts like on a Holley, you just need the highest vaccum reading, then adjust your idle speed screw accordingly.

[86shortchevy]

ill try that first i guess. thanks

[78 Chevyrado]

Sounds like there may be something different about an E-choke carb than a manual choke carb. maybe you have some parts missing that you have to order to complete the changeover?

What are you wanting to achieve by converting it to manual?

[86shortchevy]

it didnt have a choke at all when i got it.

[Newtz67]

Have u checked out edelbrocks video on adjusting the mixture screws?

[86shortchevy]

i have not, i think i just have a feeling that its something more in depth than the mixture screws.

[Newtz67]

Just off the top of my head it sounds like the choke is not adjusted correctly.

[85Bowtie]

He has a manual choke, it should be off when he chooses so.

That's why you have to mess with it warmed up. Make sure the choke plate is open when the truck is up to temp. That should be a pretty good indicator that your choke is off...or on..

[86shortchevy]

so you guys are pretty confident it has something to do with the choke and mixture screws?

[85sierraclassic]

sounds like you might have a vaccum leak somewere.

[86shortchevy]

all hoses are good. gaskets new. besides intake gasket. but motor has less than 2k miles. dont see why anything would leak. i sprayed some carb cleaner around the bases today and heard no change

[geezer#99]

What's your timing set at?

[85Bowtie]

Originally Posted by 86shortchevy

so you guys are pretty confident it has something to do with the choke and mixture screws?

I don't know for sure, it's an easy place to start though. That and the fact that I have screwed carbs up by messing with them a little at a time until I changed so much it threw everything out of wack.

The guy above me mentioned timing, that's another good point. Of course you still have to warm the truck up to check it accurately.

A vaccum leak will usually make a whistling sound, of course you mentioned your engine "loped" so I don't know how well you would hear it.

Cold weather does weird things to carbs. Do one adjustment at a time starting with your intake vaccum (these are the carb mixtures), choke, timing etc.

[86shortchevy]

timing has been in the back of my mind but i have not checked it yet. Could that tie in as well?
i will grab a vacuum gauge tomorrow and let you guys know what happens. I am also ditching the street dominator intake and replacing it with a performer eps.

[CSGAS]

Street Dominators were thrown away by most people who I knew used them--poor mixture distribution. Won't cause a "tractor sound" but will cause a rough idle. IIRC, they were also spreadbore. Since the Eddy is squarebore you are probably using an adapter. Adapters or base gaskets that are just a little off will cause vacuum and idle problems.

As stated, the "rich plugs" are almost certainly from the engine not getting warm enough to fire properly--incomplete burn, not really rich.

The Edelbrock 750 I had on a Chrysler 360 tuned fine for idle with 2.5 turns out, I'd second that suggestion about hunting down a vacuum leak.

I'd check the vacuum advance after the carb base, even if one leak is already found, to see if two problems can be solved at once. I've seen the wrong advance can installed and that could cause or cover up a timing problem. A correctly working can could reveal the tractor noise all the time; indicating a timing chain or distributor problem. No need to jump to conclusions until you check it out, as stated, WHILE WARM!

Find and solve the actual problems first, then make your own decision about if you want to change the Street Dominator out for a Strip Dominator, Performer, etc.

[CSGAS]

Another thought...you've been adjusting it a little at a time...does that include the idle speed screw? If you've opened it a lot to try to idle while cold, it will open the throttle blades beyond the idle circuits. One way to check this is to return both the mixture and speed screws to baseline, and use your foot or hand to keep the idle up until it's warm, before making any adjustments.

You may, if nothing else works, also take the carb off and look at the throttle blades when closed. If bent or misaligned, your idle quality will suffer.

No one has suggested it yet, but just in case, DO NOT even think about making any jet or rod changes until you have the idle straightened out. Neither come into play at idle.

[86shortchevy]

well that about solves the problem CSGAS, i am not using an adapter... just a gasket. I am new to carbs so im learning with this one. is this the culprit? square bore carb on a spread bore intake?

[geezer#99]

The rule of thumb is and has been for the 40 years I've worked on motors is Set your timing first then play with the carb.

[86shortchevy]

ok well what should timing be set at then?

[jrcaprai]

did you just put the carb on or did you just add a choke to the existing Carb ?

[86shortchevy]

i bought the truck and it had a holley 650 double pumper. i took that off and put an edelbrock 1406 on it. i bought the edelbrock used without a choke. so I put a manual choke on it.

[jrcaprai]

Originally Posted by 86shortchevy

i bought the truck and it had a holley 650 double pumper. i took that off and put an edelbrock 1406 on it. i bought the edelbrock used without a choke. so I put a manual choke on it.

So is this when your problems started, when you put the Edelbrock on it?

[86shortchevy]

yes.

[ppbr2001]

Originally Posted by 86shortchevy

well that about solves the problem CSGAS, i am not using an adapter... just a gasket. I am new to carbs so im learning with this one. is this the culprit? square bore carb on a spread bore intake?

Get an Edelbrock spread to square bore adapter. Don't get the open plenum type. get the one with 4 holes.