edelbrock carb issues
#1655567
08/05/14 11:12 PM
08/05/14 11:12 PM
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Joined: Jun 2006
Posts: 257
albemarle, NC
dusterbd13
OP
enthusiast
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OP
enthusiast
Joined: Jun 2006
Posts: 257
albemarle, NC
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so ive ben fighting carb issues in my duster for a while. its bad enough to where ive all but stopped driving it.
idle mixture is set properly with a vacuum gauge, with the ac compressor on, fully warmed up.
electric fuel pump, regulated to 5.5 psi.
floats set to 1/2 from the carb gasket to the top of the float with the cover inverted.
stock jets, rods, and springs.
3/8 thick insulating carb gasket.
air gap intake
so my issues are a few fold.
1. will not restart hot. seems to be vapor locking.
2. doesn't pull nearly as hard as with the 850 double pumper I had.
3. erratic idle with ac compressor on.
4. diesels on cutoff.
while adjusting float level tonight in a vain attempt to solve the hot start issue, I forgot to put the metering rods and springs back in. no covers either. the car ran significantly better when I got on it. almost like the old double pumper. I was excited. when I put the rods back in, it was back to its same old tricks. I don't know if it was all in my head, but with no rods or covers the hot start issue seemed all but gone, but I didn't really validate that well. also didn't seem to even think about dieseling.
so what am I missing? im thinking that the rod and jet combo is way too lean, causing most my troubles, and the springs too stiff. does this sound right?
please, help me out here. I just want to finish out until my leg surgery driving this car.
Michael
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Re: edelbrock carb issues
[Re: dusterbd13]
#1655571
08/06/14 01:11 AM
08/06/14 01:11 AM
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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reset floats to 7/16" and go 3 thou richer on the jets. Which eddy? what springs/what cam/what idle speed. EDIT richen the idle mixture screws
Last edited by RapidRobert; 08/06/14 01:28 AM.
live every 24 hour block of time like it's your last day on earth
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Re: edelbrock carb issues
[Re: RapidRobert]
#1655572
08/06/14 08:48 AM
08/06/14 08:48 AM
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Joined: May 2003
Posts: 15,487
Florida
scratchnfotraction
I Live Here
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I Live Here
Joined: May 2003
Posts: 15,487
Florida
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Quote:
reset floats to 7/16" and go 3 thou richer on the jets. Which eddy? what springs/what cam/what idle speed. EDIT richen the idle mixture screws
if it ran well with no needles/step up pistons/covers in the pimary jets it is way lean and that made it more than fat with a huge vac leak.
I just went from a 600 eddy to a holley 6210 650cfm spredbore dbl pumper and cant believe how much better mine runs.
ditch the eddybroke
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Re: edelbrock carb issues
[Re: Mr.Yuck]
#1655574
08/06/14 12:46 PM
08/06/14 12:46 PM
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Joined: Oct 2005
Posts: 4,945
WI
Dcuda69
master
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master
Joined: Oct 2005
Posts: 4,945
WI
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Quote:
2. doesn't pull nearly as hard as with the 850 double pumper I had.
Then put that back on.
Yep! or any Holley. There's more threads around complaining about the eddy carbs. I know the Eddy lovers will chime in but......oh well,here's some info for ya 
https://board.moparts.org/ubbthreads/show...e=3#Post8218208
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Re: edelbrock carb issues
[Re: dusterbd13]
#1655576
08/06/14 03:43 PM
08/06/14 03:43 PM
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Joined: Jan 2003
Posts: 28,067
Irving, TX
feets
Senior Management
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Senior Management
Joined: Jan 2003
Posts: 28,067
Irving, TX
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I have always been able to get an engine to run little harder with a Holley but have much better manners and mpg with the CarterBrocks. Since I don't race it was an easy decision. AFB wins. The AFB is no harder to tune than a Holley. The same basic problems happen with each style of carb. Some issues show themselves in different ways. It really helps to have eyes and hands on the carb to be able to determine the problem. It could be something as simple as a poor vacuum signal to the carb due to the lumpy cam. If the primaries are opened too far at idle it can uncover the transfer slots. When that happens you'll never get it running right. 1/2" is too deep for the floats. Back that down a bit as suggested. Get the front end dialed in for good cruise and idle. Leave the back half for making power. Quote:
1. will not restart hot. seems to be vapor locking.
2. doesn't pull nearly as hard as with the 850 double pumper I had.
3. erratic idle with ac compressor on.
4. diesels on cutoff.
1. Could be an ethanol fuel issue. The AFB fuel bowls sit directly above the manifold and aren't as isolated as the Holley carbs.
2. It should give close performance but the much larger Holley will likely make more power. In fact, I bet the 850 would pull harder than a Holley sized to match the AFB.
3. A/C compressor is going to pull either carb down. Basic physics there. If it didn't impact the 850 as much it was a sign that you likely had the idle tuned less than perfect.
4. Dieseling on cutoff is likely due to hot fuel and/or excessive timing.
The Carter AFB has a better reputation than the Edelbrock. The Eddy 750 has been a poor performer since inception due to poor reverse engineering. I understand the larger AFB has a better reputation.
Eddy carbs have different jetting out of the box based on manual or electric choke.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind.
- Stu Harmon
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Re: edelbrock carb issues
[Re: dusterbd13]
#1655577
08/06/14 05:53 PM
08/06/14 05:53 PM
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Joined: Jan 2003
Posts: 15,357
Omaha Ne
TJP
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 15,357
Omaha Ne
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Quote:
so ive ben fighting carb issues in my duster for a while. its bad enough to where ive all but stopped driving it.
idle mixture is set properly with a vacuum gauge, with the ac compressor on, fully warmed up.
electric fuel pump, regulated to 5.5 psi.
floats set to 1/2 from the carb gasket to the top of the float with the cover inverted.
stock jets, rods, and springs.
3/8 thick insulating carb gasket.
air gap intake
so my issues are a few fold.
1. will not restart hot. seems to be vapor locking.
2. doesn't pull nearly as hard as with the 850 double pumper I had.
3. erratic idle with ac compressor on.
4. diesels on cutoff.
while adjusting float level tonight in a vain attempt to solve the hot start issue, I forgot to put the metering rods and springs back in. no covers either. the car ran significantly better when I got on it. almost like the old double pumper. I was excited. when I put the rods back in, it was back to its same old tricks. I don't know if it was all in my head, but with no rods or covers the hot start issue seemed all but gone, but I didn't really validate that well. also didn't seem to even think about dieseling.
so what am I missing? im thinking that the rod and jet combo is way too lean, causing most my troubles, and the springs too stiff. does this sound right?
please, help me out here. I just want to finish out until my leg surgery driving this car.
Michael
#1 is a known edelbrock issue, GOOGLE
Edelbrock heat soak,
Edelbrock, hot start,
Edelbrock percolating
#2 There is a large difference between a 600 and 850 CFM so I am not surprised. My thought is the 600 may be a sit small while the 850 is too large.
#3 Tuning issue or may need an idle step up solenoid
#4. Tuning, idle is too high, see #1
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