Thread: Edelbrock Stumble when stompped.

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Hey everyone,
Got a prob with my car, The 750 has been running pretty good on it but if i smash it from a dead stop, i have the dreaded stumble then scream problem. I have messed around with it but cant seem to get it right, i have bigger metering rods and put the biggest springs in it. I was wondering what exactly happens when it stumbles, too much fuel dumped? do i maybe need a bigger accelerator pump? its on the biggest shot it can go right now. Well any help will be appreciated, again, i punch it, it stumbles then hauls a##.

Tech,
i went from a 7547 to a 7537, and the orange 5-in springs to the silver 8-in springs? so if i say went with a 7342 set of rods and pink 7in springs that would be richer???? and even yet the blue 3in springs and the 7042 rods that would be the richest in my kit?????? Any info would help here.

i ve been having the exact same problem on my q-jet. I'm assuming thats what Edelbrock carb your talking about. I tried different metering rods, power piston vacuum springs and different accelerator pump shots. The only other thing i could think to try would be adjusting the secondary pull off. i would be interested in hearing what any one else has to offer on this subject.

I'd agree with streets, make sure advance is working and you have no vacuum leaks. I would also venture to say you getting too much gas.

I just bought a brand new edelbrock 1406, on a 72 chevy c-10, 350, it seems to function good when I get the truck to start, it just gives me problems when I place the vehicle in a drive gear, then it bogs down, and isnt responsive at all, but in park or neutral, it is very responsive, I cant figure it out, but as far as yours, my friends truck was doing same, his problem was vaccum advance, replaced it and his truck screams now

71Nova; I had a problem like that before, ended up the rod on the fuel pump on the carb was a little long so it wouldn't get any fuel when I first hit the gas, then all the sudden it would take off. But that was on a ford carburator. I always get away from the vacuum advance in the distributor. I install the weight kit so I don't have that problem with the vacuum. Let us know what you find thanks.


Vegas

Well first I need to know the size of the engine, the relative cam specs, your trans, and your rear gear. That will get us started. People always bring me edelbrocks, Holleys, Quads, and everything else. They always say this thing isn't working right. Always remember, the carb doesn't dump fuel, the engine pulls fuel out of the carb. Let me know a few things about the car and we might be able to get somewhere. BB

71 Nova, I must say that if you don't want to change anything on the engine except tune the carb, than you definately won't see your potential for performance. If you are going to leave the thing the way it is and just tune in the carb you might gain minimal performance but it will at least run better. Start out with the car not running. Set the ignition timing at 0 on the harmonic balancer to the number one cylinder. Turn the idle mixture screws all the way in and then start out at two whole turns out on each side. The car should start but you are not done yet. Put a timing light on the thing if the idle is around 650-700. If it's idleing to high than turn the idle speed screw out until your around 650 rpm. If it doesn't want to idle down then you got a vaccum leak or something. If it does come down nice, then set the timing light at about 8 degrees BTDC. Once thats set, take off the timing light and install a vacuum gauge at a manifold vacuum source. On an Edelbrock it on the front of the carb, to the left of the idle screws. Hook the gauge there. You want to achieve the highest vacuum signal at the lowest RPM. Once you have a steady needle, hook your distributor advance to that same port. Drive it, and if you do all these things it will run much better. Other than that I have to know all about the rest of the car. BB

71 Nova, I need to know the engine size, the cam specs, the trans, the rear end gear, the vehicle weight and if it's automatic, the stall speed. This impairitive information to be able to tune on any vehicle to gain performance. Al I know is you have a 750 edelbrock. Let me know and I'll debug this thing for you.