Thanks again for the replies. As I earlier mentioned metering rod springs had been replaced by every spring in the kit with no change. My fuel pressure is varying between 3 lbs and 5 lbs...Without a regulator. So that is one thing I can try. Right now I handed the carb off to a friend of mine and asked him to try it on his truck or maybe on one of his neighbors rides. Also as earlier mentioned, while the motor was running, carb cleaner was sprayed all over the external parts of the carb to check for cracks/loose tubes...none was found. I'll keep you updated.
We've had it apart a couple times and can't seem to find anything clogged. We sprayed cleaner through the jets, took out the air mixture screws and sprayed through there, etc. Everything looks clean. We did a complete rebuild with all new gaskets and springs. It behaves the exact same way after the rebuild. We put a holley 600 on yesterday, it idled with no problem and would die out if you put your hand over the primaries. That would lead me to believe something is up with the edelbrock carb. We then put the edelbrock back on, it won't idle below say 1500 and it engine races up as soon as you put your hand over the primaries. I checked the metering rods, measured the floats, verified all the vacuum ports connected or blocked off, checked the plug in the back of the carb and set the mixture to 1 1/2 turns out. I'm stumped. The carb is ****ing air from somewhere but I have no idea where.......
That edelbrock is not intended to be run on a stock-type gm manifold! It is made to run on a square-bore manifold. The stocktype manifold has overlylarge secondaries for a quadrajet carb, if you put an edelbrock carb directly on this intake (including an edelbrock performer, rpm performer etc any intake that is a stock replacement for the gm intake) you'll have a vacuum leak at the secondaries where the intake is overly large for the quadrajet bores. Edelbrock sells a plate to seal this area off, Edelbrock part# 2732, this goes between the intake and carb.
I think he has an old Torker intake on it. Would that require that adapter plate? It sure seams like it behaves like the secondaries are behaving as you described....... Thanks, -Rich "That edelbrock is not intended to be run on a stock-type gm manifold! It is made to run on a square-bore manifold. The stocktype manifold has overlylarge secondaries for a quadrajet carb, if you put an edelbrock carb directly on this intake (including an edelbrock performer, rpm performer etc any intake that is a stock replacement for the gm intake) you'll have a vacuum leak at the secondaries where the intake is overly large for the quadrajet bores. Edelbrock sells a plate to seal this area off, Edelbrock part# 2732, this goes between the intake and carb. "
Nope, torker is suare-bore and the carb should work fine on it. The plate is only about $10 and worth a try. If you put a holley on it and it idled fine then the problem isn't with the carb per se, it is in the surface area. Internal problems, bent metering rods, porely adjusted idle circuit, trash in the bowl, high fuel pressure, float hieght et al are problems in thier own right. They are not causing the vacuum leak - once you fix the vacuum leak you might have to deal with one of those problems, just not yet. When the holley was on it did you have the same vacuum lines connected: distr, ****** & booster? If not, clamp those lines off with vice grips to isolate the carb as much as possible. Remember too, the secondaries in a edelbrock are mechanical they open right along with the primaries, there is a 'gate' above them that opens by vacuum when the engine is running. If you look down into the top of an edelbrock you shouldn't see the secondaries, you should see this gate. The gate is counterbalanced, stick a small screwdriver in there and lift it to see that it is opening smoothly and make sure it is closed properly. With it lifted you'll be able to see the secondaries benieth it. They should be closed. With the edelbrock adjusted proper the big hole on the linkage plate (where the gas pedal is connected to) should be about 10:00, rotate the throttle to about 12:00 and the secondaries should start to open. You are doing this to make sure that the throttle blades have been closed. If all that works ok then the carb gods have shate upon you and it is a good time to get that 3 X 2 setup you've been pining for. Or you can send it to me and i'll get working as a freebie, i do them all the time.
I'm always su****ous of a used intake unless you have all it's history back to when it was new. Never know when it might have been angle milled to match a set of angle milled heads or some such. But since it ran better with the Holley, I have to wonder about the Edel having some sort of leak at the base where it bolts to the manifold, cause it sure sounds like an intake air leak. All I can add to all the above is please come back and let us know what the problem is/was after you find it!Some people get all these responses that others go to the trouble to post and then fail to come back and post the solution when they do find it. The purpose of a forum is to share info and that ain't happeneing if you find a solution and don't let the rest of us in on it. Dave
No, no...I have been keeping you guys abreast of the situation and plan to continue that. I will be buying a fuel pressure regulator and trying that.
Oj may be right,, On some intakes the va***m p***ages that go around the base of AFB style carb can overhang the intake manifold flange.. Usually you can look at the old base gasket and check the impression that the carb made..
Pretty sure spaying carb cleaner with the engine running would have would have found that possibility. Thanks for your thoughts however.
Tried a fuel pressure regulator last night....no luck. I called Edelbrock tech support last night (they were quite helpful)and had me try a couple things. Phone call was cut short due to closing time out that way in CA. He said to call him back today so we can pick-up where we left off. Chuck
I had this same problem a few years ago with a carb that had set for quite awhile. I pulled both idle mixture screws and ran a welding tip cleaner rod down both ports . I found crud blocking both ports. Cleared them out and solved the problem.
For what it's worth here is the latest. Here is the carb/motor in question... When I cover the primaries with my hand the idle jumps up and the motor runs just fine(about 2000 rpm's approx.) Yet when I place my hand in font of the carb the idle drops and the motor stalls(mind you my hand is not touching anything and is about 3" to 4" away from the front of the carb) Any thoughts?
Edelbrocks are extremely sensitive to blockage of the variou air bleeds... use a welding tip cleaner to ***ure it is free of all debris and try again.
If you can cover the primarys' with your hand and the engine still runs, you have one HELL of a vacuum leak. I use starting fluid and spray a little squirt around the base of the carb with the engine running. If the rpm jumps by 1000rpm, that is where your leak is. Try blocking off the PCV valve. If it is open, that will give you an air leak. Also look at the vacuum fitting to the trans behind the carb. Spray that with starting fluid with the engine running. If you have vacuum ***ist brakes, check the booster. I had one of those bad once. Cork off the hose to the booster and see what happens. Good luck, let us know when you find it.
Where did you get this carb? Has it worked before? Is it a remanufactured carb? I bought a reman from a big parts house. The warranty expires almost before you get it installed. Yours looks like a 1406, mine was a 1407. I did most of the things you did, including a fuel pressure reg, springs, different needles, etc. Mine stumbled and hesitated off idle and had a very weak idle. I bought a new AVS series and bolted it on and it ran great out of the box. It then had a fuel percolation problem during hot starts. Fuel was pouring in through the booster venturi. I adjusted the float and put on a 1/2" phenolic insulator and then it was 100% good. In the same application, the Holley didn't need any parlor tricks to make it run. No heat isolator, no regulator, no screwing around except for the acclerator pump cam, which is very minor. I really like the Carter AFB and the Edelbrocks. Usually you can get a $20 carb at the swap meet and throw a kit into it and it runs great. These last two really did not make me happy. My new 48 project is getting a Holley 600........
I can help you out, I have this same Carter AFB knockoff, I have an 800, I see a few fun spots here. First; Edelbrock gas a good website, they run through all the basics, check them out. Next: The gas with the additives is eating our fuel hoses, Im running Aeroquip and its eating that, I get all the **** in the carb bowls. When you get the **** in the carb bowls that means your floats are getting hung up, clean them. Pull your float seats, careful theres a ****ty little stainless screen in there, is yours all full of funny black ****, clean both, blow some cleaner into the fuel rail, more black ****? put your floats back together, use a 7/16ths drill bit to space your floats, they workin nice? Pull your idle pump out and clean the reservoir, clean your jets. Brocks like 5 psi constant. That piece of link hose that is in the picture, that is gonna bite you in the ***, you need to put a clear gl*** filter at the end of all hose and run it to the carb, you want to have no hose chunks going into that stainless filter, dig? As a start point turn in the idle mixture screws all the way, hey you could even clean them first, maybe theres **** in there too, in all the way, mark top with a sharpie or whatever, turn both out 11/2, starting basis, pump arm hook up in the center, back your idle adjustment screw out till you can put a gap tool in there, no touchy, turn it in till it just touchy. Fire the gal, if she runs away on idle turn out idle, if you pull her out till she dont touch and shes still running wild your timing may be questionable, first try each of the other 2 pump arm settings, still no good, try timing out your engine with your light and your vacuum gauge and your ear, see if you can use all of these indicators to set a good time. Let me know how this works.
Jeeeeez all he said was he was having a problem. This is why the HAMB is the best. You guys are experts and many of you have come back and monitored the progress. You should all be very prooud of yourselves. Its been said, "The measure of a man is how he treats someone who can do nothing for him". I admire all of you. I've learned too.
It's been a while since I've worked around one of these carbs up close. And maybe my eyes are playing tricks on me. But does the position of the front mounting studs look strange to anybody else? I would expect to see them in either both outer or both inner mounting holes, not one of each. This thing's not mounted slightly off center for some reason, is it??? I'd sure like to see the base of the carb, the mounting gasket and the flange of the intake with everything apart. Though I still don't know exactly what I'd be looking for.
You found your leak. It is at the front of the carb. Bad vacuum hose, PVC block off, or metering jets.
I have an older Carter which is pretty much a Edelbrock knockoff, and a good friend said that I needed to put a spacer on mine cause of the way it starts after it gets up to operating temperature due to heat. Is this what you're talkin about? Mine will crank a while if it has sit for 10 minutes or so, but will start right up if it dont sit very long. It dont hot start, like the timing is too high, but acts like its out of gas. The guy said I need the one with 4 holes and not the open one for my carb so I dont loose bottom end power. (its on a 305 Chevy) The carb is about 15 years old. Thanks for any help. I've learned from the rest of you carb gurus on this thread.
Problem Solved.....well sorta. I bought a used Edelbrock 600 cfm (just like mine) for a hundred bucks off of Craigslist....bolted in on. Idle dropped right down and was able to lean out the mixture. Somebody in one of the responses offered to take a look at the problem carb. I'll go back and catch your screen name...if you were serious...I'll send it out for you to take a look at. "oj"....just sent you off a message Every body...thanks for you insight!!! Chuck
One of the outside threads for the carb studs is stripped out in the manifold so I use the inner one only on the front drivers side. Good eye but didn't cause any vacuum problems as the replacement carb seems to be functioning well.
Glad you got it straightened out! But please, when and if you ever find out what's wrong with that carb. let us know on this thread. Dave
will do.....If "oj" was serious I will send it down to him for a look-see 'cause myself and three others here in CT are stumped.
Ive seen this happen, the magic carb thing, I dont know how it was resolved either, post on this thread so we know, also, take my advice on the filter, Im going nuts over the junk in the carb. Thanks
Shout out to oj for offering to look at the carb and throw it on one of his test motors....I'll be sending it out tomorrow. Chuck
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