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HELP! tuning edelbrock carb


labrat

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Ok, here's the deal. Been trying for a couple of hours to tune this carb, but not having any luck. It's an edelbrock 1407 750 vac secondary on a sbc 350. It will run like a demon and smoke both tires mercilessly once I get on it, and it idles pretty decent in Park, but I can't get it to stay running in gear without holding both pedals and looking like a leashed tiger. I've followed the procedures in the manual, but it looks like the idle circuit is not working at all, as I have to open the throttle blades enough to uncover the transition slots to even get it to idle at all. Then, put it in Drive, and it dies. I'm at a loss here, about to just switch to my backup carb. I know my cam is not radical enough to make me do this, it's only 272* advertised duration (can't remember @.050) and .454 lift. This shouldn't require any serious throttle blade opening for idle, should it? Anyway, as always, help is definitely appreciated!!! Btw, this is now my daily driver and has to get me to work tomorrow! Thanks again!

 

Bill

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Guest Anonymous

I too had that problem. I have a SBC w/ 295cams and an edelbrock 600. My car would die if i turned to quickly or pushed the brakes at idle...is this what is happening to you? All i did was adjust idle fuel/air mixture and then set idle a tad above 750, about 775...see if that helps

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Okay, i have it narrowed down to a vacuum leak. I held my hand over the choke horn to manually choke it, and at about 75% coverage, the motor roars to life. I think the leak is around the base of my carb, but i'm afraid to torque the bolts too tight, don't wanna rip the threads out of my aluminum manifold. Anyone have any ideas on sealing an edelbrock squarebore carb to an edelbrock 2101 performer manifold? I was gonna call edelbrock, but they are only open mon-fri. Any ideas here? Thanks GREATLY!

 

Bill

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Ok, i've looked at this some more, and i think I may have warped the aluminum manifold when the motor overheated right before I tore it down. Is this possible? Likely? Certain? It just seems that no matter what I do, I can't get this carb to seal. Any input is greatly appreciated!

 

Bill

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Guest Anonymous

That is a possibility that you warped it...i have similar intake (holley street dominator) which is also aluminum and i torqued the hell out of it no problems...but if its warped then you also have the possibility that its not leaking at the carburetor mount and that it could be leaking around the heads and block which would definitely explain your situation...just my .02

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This may sound stupid but to check for vacuum leaks the poor mans way take a piece of fuel line 12 to 18" long and put to your ear and then scan over all area's where an intake leak could occur. Just hold it real close to the area checking 1/2" or so but no more and if theres a leak you will really hear it if you have a leak.

 

Then torque bolts down in that area. Probably sounds crazy but works wounders for me.

Mike

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Thanks, i'll try that! I have now used 17 bux worth of different thickness gaskets thinking it was between the carb and base, and now it runs better, but I think it may be somewhere around the heads, maybe even underneath. Is there any way to check the bottom side? WOuld it be burning mucho oil if it was leaking there? I will try the hose trick, I didn't think of that. I have yards of spare hose laying around, from 3/8 to 1.5", so I will try that tomorrow. The only problem is I will have to drive it this way for right now, I gotta get to work and school tomorrow, and get home around 11. Ugh!

 

Thanks for all the help guys, i really appreciate it!

 

Bill

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Guest Anonymous

A shot of barryman's chemtool around all intake gaskets with the engine running also will detect a leak. When you hit the leak you'll hear a rise in the engine RPM. It works real well and as a side note, chemtool (the old stuff not sure if they changed it) makes a great flame thrower with a lighter lit in front of the hose. :D

 

Regards,

 

Lone

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Originally posted by LoneInAZ:

A shot of barryman's chemtool around all intake gaskets with the engine running also will detect a leak. When you hit the leak you'll hear a rise in the engine RPM. It works real well and as a side note, chemtool (the old stuff not sure if they changed it) makes a great flame thrower with a lighter lit in front of the hose. :D

 

Regards,

 

Lone

NOPE! They have not changed a thing--still makes a great flame thrower!!!!! :D

 

Davy

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Yeah, thawk, it's a beatiful carb and runs great once I get off-idle, (left two long smoky black streaks in front of the house on my test drive) I just can't get it to idle properly in gear. I don't think thats the carb's fault though. I like it cuz the red powder coating matches my red distributor cap ;)

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