No More Carb Issues...BUT...
C3 Corvette Enthusiast
Joined: May 2008
Posts: 1,071
Likes: 3
HOWEVER, I have read about some tuning nightmares about both Holley and Edelbrock carbs on the Mustang and Mopar forums.
Good luck in fixing your problem.
P.S. - Another forum I'm a member of had this thread about Holley vs Edelbrock on ZZ4's. Eddy's are great carbs (just as Holleys) - both have their idiosyncrasies and both have to be tuned correctly. They're hard to find these days but try to find a mechanic who understands carbs and have him jet and adjust it properly. Believe me, it's worth the money.
http://67-72chevytrucks.com/vboard/s...d.php?t=561424
Last edited by American Raven; Aug 6, 2013 at 06:46 AM.
Le Mans Master
Joined: May 2007
Posts: 5,031
Likes: 1,121
From: North tonawanda NY
What makes an Edelbrock carb questionable at best? there are thousands of them installed on cars and hundreds on this forum alone. The car had a Holley 750 DP originally. It made the car run like crap. I changed to the Edelbrock because it was a 600 cfm. The same cfm that the car came with. Plus I gained the manifold port back. The previous owner installed a bolt in it then installed the Holley, and "T'd" all the vacuum off it. Funny thing is, this all started just to get the lights to work properly. The PO said the lights quite after the carb install. Well, he lied. And about other things as well. I will try and block off all the vacuum and see what happens. I tested everything before i installed them, and the only thing that created a vacuum leak was the booster, which I suspected needed changed. Also, I will change the timing vacuum assist to the driver side port and see how that works. I also bought some Sea Foam, and a new distributor as well. After that it is either valves, wires, or timing? Thanks everyone. I will let you know what i find.
I had a similar popping issue on my 74 which I found was caused by the heat controlled flap in the passenger side exhaust manifold being messed up and mispositioned and causing exhaust blockage on that side.. other possibilities is a leak in intake/Carb seal or exhaust or even a plugged cat if you have one....you can hit it with a temp gun to see if its overheating which they do when the are plugged....
Last edited by augiedoggy; Aug 6, 2013 at 08:06 AM.
Racer
Joined: Nov 2003
Posts: 386
Likes: 1
From: Grafton WV
I have a Edelbrock 1406 on my 81 and it works great also have a 1103 cam in it and love the sound. Have no idea what the horsepower gain was if any but I was after the lopey cam sound not especially HP. Isn't this a wonderful country where we can choose the things we want right or wrong.
Burning Brakes
Joined: Oct 2011
Posts: 956
Likes: 86
From: McDonough Georgia
Original qjet was a 750.... but otherwise your right the edelbrock its the most commonly used Carb...not the best but certainly not junk...they are one of the simplest designs and easiest to setup and maintain.... unfortunately many people stick to what they know and put down everything else....same reason so many remove the qjets as few understand them correctly.
I had a similar popping issue on my 74 which I found was caused by the heat controlled flap in the passenger side exhaust manifold being messed up and mispositioned and causing exhaust blockage on that side.. other possibilities is a leak in intake/Carb seal or exhaust or even a plugged cat if you have one....you can hit it with a temp gun to see if its overheating which they do when the are plugged....
I had a similar popping issue on my 74 which I found was caused by the heat controlled flap in the passenger side exhaust manifold being messed up and mispositioned and causing exhaust blockage on that side.. other possibilities is a leak in intake/Carb seal or exhaust or even a plugged cat if you have one....you can hit it with a temp gun to see if its overheating which they do when the are plugged....
Chances of this issue being with the Edelbrock are remote.
"popping" can be caused by so many issues that you really need to tackle it in a systematic manner.
I always try to start with the simplest first and work my way up.
1. Vacuum leaks. A very elusive culprit, but common on the C3. Block off everything, then connect them one by one and check for pops.
2. Intake leak. Spray a little marvel mystery oil around the manifold and carb. Look for a leak.
3. Ignition. timing, plugs, wires. Try and see if the pop is isolated to one cylinder. It probably is.
4. Adjust valves if everything above seems ok.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Bet your carb issue is an ignition issue
Eddy carbs seem calibrated to a stock setup usually a touch lean.
They are not bad just like any carb most may need a little tweaking out of the box to work best for your app.
Eddy carbs seem calibrated to a stock setup usually a touch lean.
They are not bad just like any carb most may need a little tweaking out of the box to work best for your app.
Thread Starter
Pro
Joined: Feb 2005
Posts: 616
Likes: 2
From: Sedalia MO
UPDATE!! First and foremost thank you all who have suggested possible solutions. I disconnected the vacuum advance and reconnected it on the driver's side port. I am pleased to announce the popping is gone. But, now it is in the yellow as far as vacuum goes and my eyes are burning from the gas smell. Is it possible I need to advance my initial timing now? I am pretty certain I do not have a vacuum leak around the carb area. I sprayed carb cleaner around the base and heard no RPM change. I buddy that helped me time the car said he set it between 6*- 8*.
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Melting Slicks
Joined: Mar 2007
Posts: 2,520
Likes: 11
From: Hinckley OH
Now I'm confused. Your original post said it was popping at all RPM's. Moving the vacuum advance to the driver's side would change it from ported vacuum to manifold vacuum. The only difference that should make is at idle. Once you open the throttle above idle there should be no difference based on which port you use unless you failed to plug the port on the passenger side. I didn't see whether the popping was at the carb or through the exhaust.
Thread Starter
Pro
Joined: Feb 2005
Posts: 616
Likes: 2
From: Sedalia MO
Was popping at all RPMs. Don't know what to say, but it isn't popping since I reconnected the vac to the driver side. My idle RPM went down when I did. It raised on the passenger side. I think it just solidifies I have an ignition problem. But, what problem? Timing off? Which I suspect is the culprit because it is an aftermarket intake. Let me just say, the car is running 10 times better than it was with the 750 Holley. Not saying Holley is crap or Edelbrock is better. What I am saying is, the Holley had issues, such as vacuum leaks. The car was also not firing on all cylinders, now is do to new plugs. I just want this thing to run decently until I can save up for my new crate engine.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Do you have the 'correct' baseplate gasket installed under the carb. That gasket has holes in specific spots to direct manifold vacuum where it should go for THAT carb. Or, if not correct, it could bleed off manifold vacuum so that carb ports might not work properly. See if you can research a photo of the correct gasket for that carb and verify the one you got/used is right.
Racer
Joined: Apr 2009
Posts: 331
Likes: 44
From: Cincinnati Ohio
Before you go make hardware changes make certain you have the car properly timed and your distributor is working properly. First check to make certain your mechanical advance is freely working. I have seen broken springs and old grease gum them up which causes issues. Then get someone with a dial back timing light and knows what they are doing to time the car. The best way I have found is to disconnect and plug the vacuum advance hose and then set the timing so that you have around 34-36 degrees of advance when the mechanical advance is fully in which should be between 2000-3000 rpm depending on your distributor. That means that if your distributor mechanical advance is 20 degrees that your base distributor setting would be 14-16 degrees. Once this is set then reconnect your vacuum advance.
Unk
Unk
Racer
Joined: Apr 2009
Posts: 331
Likes: 44
From: Cincinnati Ohio
I forgot to add that if you are having fuel burning your eyes, it is running rich and you need to adjust your carb. In an earlier post you stated that you had the idle screws about 2 1/2 turns out. The factory tells you to start with 1 1/2 turns. Then turn them in until it starts to stumble and then back them out to get maximum RPM and then reset idle speed. They have a good video on their website to show you how to do it. You should fist get timing set, then adjust your carb.
Unk
Unk
Thread Starter
Pro
Joined: Feb 2005
Posts: 616
Likes: 2
From: Sedalia MO
UPDATE...again: IT IS RUNNING GREAT! I never claimed to be the sharpest peanut in the turd. Yesterday, when I started it, it was running rich and burning my eyes. It also ran a bit rough. I thought is was a timing issue, or some other ignition issue. Well, I guess I was right...sort of. I went out to mess with it after work and noticed...DOH!, I forgot to connect the driver side spark plug wires. Yes, all of them. Reconnected them and VOILA! Running great and pulling 16" of steady vacuum. I plugged the brake booster back in and the vacuum went down, but I know I need a new one. Again, thanks for all the help. The manifold vacuum connection seemed to do it.
Burning Brakes
Joined: Oct 2011
Posts: 956
Likes: 86
From: McDonough Georgia
I believe it's more a case of "those who live in glass houses shouldn't throw stones".
Anyone who has been working on these old beasts has done more than a few bonehead things.
I'm glad for you that was all it was.
Anyone who has been working on these old beasts has done more than a few bonehead things.
I'm glad for you that was all it was.
Racer
Joined: Feb 2013
Posts: 386
Likes: 3
From: Clifton Virginia
UPDATE...again: IT IS RUNNING GREAT! I never claimed to be the sharpest peanut in the turd. Yesterday, when I started it, it was running rich and burning my eyes. It also ran a bit rough. I thought is was a timing issue, or some other ignition issue. Well, I guess I was right...sort of. I went out to mess with it after work and noticed...DOH!, I forgot to connect the driver side spark plug wires. Yes, all of them. Reconnected them and VOILA! Running great and pulling 16" of steady vacuum. I plugged the brake booster back in and the vacuum went down, but I know I need a new one. Again, thanks for all the help. The manifold vacuum connection seemed to do it.
Thread Starter
Pro
Joined: Feb 2005
Posts: 616
Likes: 2
From: Sedalia MO
At least I am not the only one then. I was so thankful to be able to drive it (Somewhat). My wife was involved in a fender bender last night. Of all people, it was my boss, the Maintenance Chief Master Sergeant of my squadron. She was very empathetic though. So now at least I have the Vette to drive while the car is getting fixed.