Hello folks...

Here is my question. I have an Edelbrock 4bbl installed on a stock 429 with stock intake, oem electronic ignition and Thorley headers. Seemingly aginst my better judgement I listened to a parts guy when he sold me the thing. He was testifying to all the virtues of the Edelbrock vs the Holley. Being a Holley guy (who's had lots of them) I was a hard sell...but buckled never the less to the supposed modern improvments of the Edelbrock. The carb is sitting on top of a plastic 1 inch spacer and is wearing a 14x5 open air cleaner. I have never been all that impressed with this carb since the install. I have a few complaints that lead to questions for you folks.

1 the choke is really odd in terms of adjustment. It seems like it is all or nothing. More turn of the cap to get a bit richer when cold seems like too much...and then back it off just a smidge...and it has no choke at all. It will go from screaming at idle...2500-3000 rpm...to no choke and no idle up ...with just a tweak of the choke cap. Needless to say this is a pain to adjust because it doesn't take long and the engine is too warm to be adjusting the choke. I have to let it cool off again. I have spent most of a day trying to get this right. Nowadays I just pump it twice to get it to start and hold my boot on the throttle @1200 rpm till warm enough to drive it. Every other carb I have had I could stroke the pedal once and start it and walk away. Hmmm.

2 there is no noticeable change in engine ouput from two to four barrels. I know that with Holleys you can feel the vacuum secondary open. With the Edelbrock I can't feel that happen so I don't know when the back two are coming on. With the Holley I could change secondary springs to time the event. With the 4.11 gears and higher engine rpm at cruise I suspect that it might be open more than it should be. I can't tell. What I can tell ya is that it gets about 7-8 mpg. I can tell ya that the tail pipes are black.

3 The darned thing WHISTLES all the damn time. I have looked till I am blue in the face for a vacuum leak and it doesn't seem to have one. I have listened with a hose. Sprayed propane... sprayed carb cleaner.. can't find a thing. It whistles worst under acceleration when vacuum should be at an all time low. I don't get it.

4 the idle adjust screws don't really do squat most of the time. IF I close them most of the way off. Then it stumbles. IF I open them up like 4 turns it will stumble. I have never had a Holley that had this broad of an acceptable setting. All the holleys I have had liked a very narrow precise sweet spot on the idle screws. I currently have them set at about 2.5 turns out.

Now I don't know if some of the performance issues are just traits of the Edelbrock but if I could eliminate just one thing above it would be the damn whistling. I think it comes from down the venturi. I am not sure. Overall it runs ok. It has a little flat spot just after a gear change then smooths out. It does make power at wide open throttle. It will go like stink if I floor it when at hot operating temps. The mid range performace is rather lack luster. Yes it goes down the road ok but doesn't seem like the pedal is even hooked to the throttle plates. I opted for the 600 cfm size looking for exceptional throttle response. It isn't all that hot. I have adjusted the lever holes on the accelerator pump. Not much change. More squirt just makes the exhaust stink of fuel.. Less squirt doesn't make a stumble. Seems like most things I can adjust on this carb have minimal effect. All except for the choke. Which is LOTs or nothing. I blew my spare cash on this carb and now after struggling with it for a year and a half...there is no returning it. I am seriously thinking about hitting the wrecking yard for a take off Holley and stopping at NAPA for a rebuild kit. I will admit one thing...it sure is shiny.. I have the timing set at 10BTDC and am running Autolite 45 (I think that is the right number) plugs. All of the engine is simple stock stuff that is easy to get in line. All of the operating issues came along after the carb went on. It used to run better with the old clapped out Motorcraft 4bbl. Funny thing is that I changed it because the throttle shaft bushings are WAY sloppy.

Thanks
Bill

 

About me:

I just got an Edelbrock 1450 4bbl (600cfm) non-EGR for free. I have yet to put it in my car. I need to add an electric choke (part # 1478) to it when(or if, after reading your post!) I install it.

I'd be installing it onto my 1981 Olds Delta 88. The stock 4bbl Quadrajet is aging and needs help/rebuilt/or thrown in garbage...eng size is 307 V8

Any advice for me?

About you:

The only thing I can offer is that the whistling is probably coming from the spacer plate.

Is the spacer plate a 4-hole or a one-big-hole? That might cause it.

The whistling gets louder under acceleration, this happens when more air enters the carb and flows down the venturi and past the spacer plate...might be it...

You're last paragraph describes how my Delta runs exactly and I KNOW my choke has had it, I have to pump twice and hold the revs up til the eng warms up too. The performance is better at hot temps and mid-range is lacking too and it does GO when I put my foot in it.

 

Sounds to me like you need to change the metering rods and possibly the springs. They make a tuning kit with several jets, springs and metering rods to do this. It sounds a bit lean on the part throttle, I believe that smaller metering rods are in order to correct your problem.
Not sure on the choke, Mine has always opened about 1/4 inch right after start-up and then slowly opened the rest of the way as it warms. Perhaps the spring is not properly seated inside against the choke lever in the housing.

 

I have the 1406 on my 400 I like a lot better than the holley I got rid of the holley when I went to adjust the float level and the lovely fiber gasket that "seals" the nut fell apart and the carb was only only 8 months old. Got tired of all the fuel spillage and gasket changing just to tweak the jets. To set that high idle on the 1406 there is a fast idle adjustment screw it is kinda difficult to get to but its there. All you gotta do is screw it in or out to your desired rpm and youre good. For tuning get the edelbrock tuning kit and start tinkering,comes with a book that has different setups for more power or mileage gives jet sizes rod sizes for both. Once you start tinkering with it you'll know the advantages of the edelbrock.

 

I have installed, adjusted, and used many carbs, Holley, Quadrajet, Carter/Edelbrock, as well as Webbers and Motorcraft.

Is your choke even hooked up? We can assume that since you are adjusting it that it is an electrical choke. Chokes that are not hooked up to 12V properly behave like you describe.

A 1" open spacer can cause all sorts of low end problems.

The whistle is a vacuum leak which will also make it impossible to adjust the carb.

If your throttle plates are not set properly or you have a vacuum leak you will be operating on the main jets and the idle jets will have little effect.

Usually the Edelbrock carbs can be installed and they will run ~OK right out of the box. A small idle mix and speed screw as well as small choke adjustments are all that is required to make them run well. To get optimal performance the tuning kit is required.

Get rid of the 1" spacer and the worthless open air cleaner. Put a proper aircleaner on with a thermostatic control to avoid carb icing. Those open aircleaners are horrible. They are really only good for trailer queens and hotrod shows where the vehicles only have to look good, not be functional.

Sounds like you need to go back and read the installation and adjustment manual, then just hope you can fix all the adjustments you have messed up.