edelbrock carb issue

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oldjunk

oldjunk

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Hey guys,
Here is my setup. 600cfm edelbrock carb, performance cam (unknown, noticeable idle) and headers. Everything else is basically stock. I am having trouble with a very rich mixture. Adjusting the fuel/air screws seems to have no effect. I am also hearing a loud tapping noise coming from my metering rods when the engine is at operating temp. Sometimes I can get that noise to go away while reving the engine a couple times. I am also having trouble starting the car when hot. I takes a couple seconds for the engine to turn over vs starting up immediately when cold. I did take the car to an old mechanic who actually builds race cars thinking he could easily fix the problem. He ended up disconnecting my vacuum advance and plugging the vacuum adv. port on my carb. It seems to run a little better, but the rich mixture and the noisy metering rods have me worried. Has anyone ever had these type of problems or know what could be wrong? Thanks guys.

-oldjunk
 
unscrew the cap that covers the metering rods...start engine and watch it...

is it opening and closing went it idles???

you might need to change the step up spring to keep the rod down in the jet...which leans it out...
 
70aarcuda said:
unscrew the cap that covers the metering rods...start engine and watch it...

is it opening and closing went it idles???

you might need to change the step up spring to keep the rod down in the jet...which leans it out...
Click to expand...

I will check that out. I know the mechanic I took the car too changed the springs. I know that edelbrock uses a color code system for their springs...any suggestion on what type I should replace them with? I guess it's a trial and error thing. My mechanic said he thinks the engine is not getting enough air. If this doesn't remedy the problem do you thing changing the carb? Possibly going bigger? I'm a complete novice when it comes to carb issues. Thanks for the input!
 
oldjunk said:
Hey guys,
Here is my setup. 600cfm edelbrock carb, performance cam (unknown, noticeable idle) and headers. Everything else is basically stock. I am having trouble with a very rich mixture. Adjusting the fuel/air screws seems to have no effect. I am also hearing a loud tapping noise coming from my metering rods when the engine is at operating temp. Sometimes I can get that noise to go away while reving the engine a couple times. I am also having trouble starting the car when hot. I takes a couple seconds for the engine to turn over vs starting up immediately when cold. I did take the car to an old mechanic who actually builds race cars thinking he could easily fix the problem. He ended up disconnecting my vacuum advance and plugging the vacuum adv. port on my carb. It seems to run a little better, but the rich mixture and the noisy metering rods have me worried. Has anyone ever had these type of problems or know what could be wrong? Thanks guys.

-oldjunk
Click to expand...


You didnt say what engine you have ?

Start with an orange spring.Thats what came with your 600 out of the box.

Ede carbs have a problem with heat soak. You need to run some sort of spacer/heat insulator to cure the hot re-start issue.
 
Johnny Dart said:
You didnt say what engine you have ?

Start with an orange spring.Thats what came with your 600 out of the box.

Ede carbs have a problem with heat soak. You need to run some sort of spacer/heat insulator to cure the hot re-start issue.
Click to expand...

Sorry about that...it's a 340. I ordered the calibration kit today (includes rods, springs and jets). I guess I will have to play around with different setups. Do you think that by just changing the springs I could lean out the carb or do I have to change all 3 (springs, rods & jets). Like I said, I'm a complete novice when it comes to carbs, but am willing to learn. I'll look into the spacer/heat insulator. Thanks a lot for your help.
 
The best thing to do would be to go through this carb,clean it,and blow out all passages.
Make sure the floats are adjusted corectly,and set the jets,rods,springs,to the box stock setting's.Then you have a starting point. I doubt this 600 is running rich on your 340.Someone would have had to jet the thing up big time.Besides running a little rich is better than running lean.

Personelly I think your a little under carbed,loosing out on the topend. But,with the right tunning, you could make this carb run real well on your 340.
 
Johnny Dart said:
The best thing to do would be to go through this carb,clean it,and blow out all passages.
Make sure the floats are adjusted corectly,and set the jets,rods,springs,to the box stock setting's.Then you have a starting point. I doubt this 600 is running rich on your 340.Someone would have had to jet the thing up big time.Besides running a little rich is better than running lean.

Personelly I think your a little under carbed,loosing out on the topend. But,with the right tunning, you could make this carb run real well on your 340.
Click to expand...

Thanks Johnny...I'll take your advice and tear down the carb.
 
Hey oldjunk, it's funny that your post is almost like the problem my carb just developed a few days ago. Mine seems to only affect the idle circuit, so I am thinking something got in there and is blocking the air from getting to the engine. The rebuild kit for these is not cheap now that everything new is FI. Ugh
 
I was having similar issues with mine as well. But I figured out the perfect solution..........Put a Holley on it!
 
Well cb66valiant
I looked at that option as well because I have a 780 vacumn seconday Holley but when I went to the parts house to get a rebuild kit, NO GO :-(
Does anyone know where to get a rebuild kit for a 7710 Holley?
We all know that the Holley have more top end but the AFB and AVS carbs are much more responsive and get better mileage.
Open to suggestions
 
belmateo,

I'll bet you have a "3310" Holley, not a 7710.

Give me an Edelbrock on the street.

My race car has a Holley.
 
Hey Racer426
You are probably right, it's a 780cfm. Where can we buy rebuild kits and fuel lines for these vintage carbs now?
I agree with your carb selection for the street and strip!
 
Summit has them. They should be available at most Performance outlets.

R3310-1 takes Kit 37-1539. Summit $95.95
This is actually a Universal Kit that fits MOST Holleys.

R3310-2 thru -7 takes Kit 37-119. Summit $23.95
I'll bet the 37-119 would probably work. Ask Summit.
 
OldJunk - Had the exact same issues w/ my Edelbrock carb.

The "tapping" noise you hear is junk (particles) of crap in your carb. I had rust in my tank and found out that clogged it up! Pull the carb and clean it out real good and blow it out....I did it multiple times before I was able to replace my tank.

Definately get an insulator gasket! Either a small 1/2" spacer of some sort or atleast the Edelbrock insulator gasket (Part# 9266). It worked pretty good for me and helped hot start issues.

Your running rich 'cause most Eddy carbs do! The calibration kit should help.....

Here's the link to the gasket on Summit:

http://www.summitracing.com/parts/EDL-9266/

Best of luck...I ended up going to back to a Holley 650 Double Pumper on my 340...I just didnt like the performance (or lack of) and issues w/ the Eddy carbs.
 
Thanks much Racer426 !!!!
I looked at the image and sure enough it appears to have most gaskets and seals for Holley. As far as I can remember, the only issue would be the body to throttle plate gasket, but I will be very very careful when I take it apart just in case.
I will order that today from Summitracing after I verify my carb number
 
So I bought a vacuum gauge. I am only getting 8 inches of Hg. What could be causing such a low reading? Could this be causing my carb issues?
 
oldjunk said:
So I bought a vacuum gauge. I am only getting 8 inches of Hg. What could be causing such a low reading? Could this be causing my carb issues?
Click to expand...

That and the perf. cam. Also make sure the timing is set correctly as that'll cause low vacuum.

My 360 only pulls 8 inches of vacuum but that's because of the cam.

I agree with Tony that it sounds like the metering rods are bouncing and hitting the covers. Lighter step up springs should cure that. Once you install the lighter springs adjust the idle mixture screws for the highest vacuum reading with the car in drive and the park brake set.
 
i had a darkside 72 monte carlo with 780 damn it was fierice but it was feeding a 454 so what can i say ive seen the light now mopar forever but i sure do miss that old ss monte
 
fishy68 said:
That and the perf. cam. Also make sure the timing is set correctly as that'll cause low vacuum.

My 360 only pulls 8 inches of vacuum but that's because of the cam.

I agree with Tony that it sounds like the metering rods are bouncing and hitting the covers. Lighter step up springs should cure that. Once you install the lighter springs adjust the idle mixture screws for the highest vacuum reading with the car in drive and the park brake set.
Click to expand...

Ok, glad to know that the cam is responsible for such a low vacuum reading. I changed the springs to the lightest in the kit (blue). I haven't noticed the tapping since I put them in. The reason I believe it's running rich is because it exhaust fumes are enough to burn your eyes. I have also been told this by a couple people who have looked at the car. I also see blue smoke coming from the drivers side tailpipe only...still with the new springs installed. I don't smell oil though...just a rich mix. Could this mean I might have some issues with valve seats or piston rings?
 
I could be wrong but from my experience Blue smoke out the tail pipe is not from richness it is usually from excess oil in the combustion chamber be it from a valve seal, cracked or worn ring(s) etc.
 
oldjunk said:
Ok, glad to know that the cam is responsible for such a low vacuum reading. I changed the springs to the lightest in the kit (blue). I haven't noticed the tapping since I put them in. The reason I believe it's running rich is because it exhaust fumes are enough to burn your eyes. I have also been told this by a couple people who have looked at the car. I also see blue smoke coming from the drivers side tailpipe only...still with the new springs installed. I don't smell oil though...just a rich mix. Could this mean I might have some issues with valve seats or piston rings?
Click to expand...

Good. Try adjusting the idle mixture screws (the 2 screws sticking out of the front side of the carb) for best idle. Turning the screws in leans the mixture while screwing them out enrichens the mixture. Yeah unfortunately blue smoke is generally worn rings or valve guides/seals so it's never good.
 
Old Junk: Have same engine and carb issues as you. New carb, new engine with only 200 miles on it. Awful rich! Idle screws are set to best idle and vaccum. Everything else is set to specs that I can see.

Have you had any luck in getting your straightned out? If so, what did you do?

Thanks
 
A340 said:
Old Junk: Have same engine and carb issues as you. New carb, new engine with only 200 miles on it. Awful rich! Idle screws are set to best idle and vaccum. Everything else is set to specs that I can see.

Have you had any luck in getting your straightned out? If so, what did you do?

Thanks
Click to expand...

Only trouble I ever had out of an edelbrock was a hole in a float, burned rich, idled fine, would bog if you kicked it on take off... I kept thinking it was my timing, just a bad float in mine....
 
Only trouble I ever had outta a Edelcrap is I missed the trash can with one, once. Ditch the Junklebrock and slam a Thermoquad on it.
 
StrokerScamp said:
Only trouble I ever had outta a Edelcrap is I missed the trash can with one, once. Ditch the Junklebrock and slam a Thermoquad on it.
Click to expand...

StrokerScamp,
I have the original carter thermoquad that came with the car. Would it be worth rebuilding?
 
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