Carburetor Advice

[Hugh Mongus]

I installed a new Edelbrock carb a few days back. I have also done some other things that have made my truck run 110% better than when I bought it. However, for some reason if I floor it, it seems like it has more to offer but something is holding it back. I don't know a good way to explain it. Looking for advice on different things I could check, adjust, change to maybe wake it up to its full potential.

[BMERDOC]

One tip: Make sure the throttle blades are completely open when the pedal is mashed to the floor.

[Fleetline Fever]

With that limited amount of info it's hard to say. I would start with the ignition, Check the timing. How is everything else with the ignition, Plugs, cap, rotor? Is it HEI or points?

[Steeveedee]

Go buy the needle and jet kit, complete with instructions. I don't remember the number. But you'll have to tune it a little bit to get it right.

[Hugh Mongus]

Originally Posted by fleetline

With that limited amount of info it's hard to say. I would start with the ignition, Check the timing. How is everything else with the ignition, Plugs, cap, rotor? Is it HEI or points?

HEI dizzy with new Accel wires, Accel coil, Accel cap & rotor, new AC Delco plugs, new ignition module, new vacuum advance. I set the timing to 12 degrees but it dieseled when shut off so I backed it to 10 degrees and seems good.

Originally Posted by steevedee

Go buy the needle and jet kit, complete with instructions. I don't remember the number. But you'll have to tune it a little bit to get it right.

Are these kits easy to understand for non-mechanics?

Originally Posted by bmerdoc

Go buy the needle and jet kit, complete with instructions. I don't remember the number. But you'll have to tune it a little bit to get it right.

I'll check that. Maybe the carpet is preventing full throttle.

[jmorri34]

Originally Posted by Hugh Mongus

I installed a new Edelbrock carb a few days back. I have also done some other things that have made my truck run 110% better than when I bought it. However, for some reason if I floor it, it seems like it has more to offer but something is holding it back. I don't know a good way to explain it. Looking for advice on different things I could check, adjust, change to maybe wake it up to its full potential.

I have the exact same setup and exact same problem and I am still trying to figure it out but I'll tell you what helped me. First pull the plugs and see if the truck is running lean or fat, white cone on the plug is lean and black is fat.(Pardon the instruction I just dont know how much knowledge you have). Ideally you want a brown or copper colored cone on the plugs. Mine was very lean so the first thing I recommend you do is find what carb you have (Mine is a 1406) and go to Edelbrocks website and the have a technical section just to help you tune the step on each specific carb, its done me a world of good. To set your mind at ease these carbs are VERY easy to tune on and thats hard for me because I am a diehard Holley person . They have easy to change metering rods you dont even have to take the carb off to change and they will help you tune it (there is a video on youtube showing exactly how to do it). Ok back to the tuning website, There is a chart that gives you the base setup and it shows you exactly what to change to either fatten or lean up the carb by changing rods, jets or a combination of both and even gives you part numbers to do it. I am like the other poster above in thinking its better to get the tuning kit for your particular carb, likely cheaper on ebay. Then by following the tuning chart it has helped me tremendously and I am finally creeping up on what the truck wants. In my case the PO didnt know what they were doing and I have gone up 16% on the fuel and changed the timing and finally getting the engine where it wants to be but I still have some to do. Be lieve me you dont have to be a carb guru to do this. I started a week ago and I had never touched one of these before and I had the whole carb apart to clean it and back together in no time flat. Let me know if this helps and if you need anything else, Ill be glad to help if I can.. Jerry

[geezer#99]

Bump the timing up. 14 to 16 initial. Hook the vac advance to manifold vac port. Turn your idle back down so it won't diesel.

[GMCJOE]

Sell the Edelbrock and buy quadrajet from http://www.smicarburetor.com/products/sfID1/28/sfID2/9

Problem solved.

Edelbrock is a good out of the box performer with easy setup and tuning.

[Hugh Mongus]

Geezer- When my timing was at 12 degrees I had the idle set 800 in park which put it around 500ish in gear. I don't think the idle speed was causing the dieseling. I will try 14 and 16 to see how it acts.

Today I did verify the carpet and underlayment isn't preventing wide open throttle. I also pulled a couple of plugs and noticed they are a little darker than they should be. Maybe I should lean it out a bit.

I'm sort of stuck for a few days though. I installed headers this weekend and I am waiting for my appointment at the local exhaust shop.

[BMERDOC]

See if the exhaust shop has a Gas Analyzer they can hook up after you get your exhaust installed. Maybe that can shed some light on the situation.

[i82much]

Accelerator pump!!!!!

[geezer#99]

Idle speed or throttle opening always causes deseiling. If you hook vac advance to manifold then your in gear idle will come up enough that you can bring your in park idle down.
If the throttle is closed, no air gets in to draw fuel with it to make it desiel.
If your plugs show a bit rich you'll need a fuel regulator. Eddy's don't like more than 5 psi.

[Hugh Mongus]

Swapped the dizzy vacuum to manifold today. Advanced the timing to 14 degrees, and reset the idle. It starts easy, idles good, and shuts off good. I will be driving it to the exhaust shop in the morning, so I will see if it runs better tomorrow. Going to be a loud ride in the morning.

[Hugh Mongus]

Geezer- I picked my truck from the muffler shop at lunch today. It has more pep with the advanced timing and vacuum on manifold vice ported. I will probably advance it up to 16 degrees and see how it does there. Then decide where to set it. Thanks for the advice.

It was sure nice driving it today with no exhaust leaks and loud ass glass pack noise in the cab. I could actually hear the radio. lol

Buying a fuel pressure regulator on the way home tonight.

Thanks again!

[ole dollor]

just a simple question on this....when you went to hei dist. where did you get the power to run the dist. are you sure its a full 12 volts....good luck on your truck.

[Hugh Mongus]

Originally Posted by ole dollor

just a simple question on this....when you went to hei dist. where did you get the power to run the dist. are you sure its a full 12 volts....good luck on your truck.

When I bought this truck is was a wiring nightmare. The wire to the dizzy was coming out of a switched blade of the fuse panel. The wire was 2x as long as it need to be and not a very good quality wire. I figure it was a reclaimed piece of wire as faded as it was. I ripped it out and replaced it with a new 10 gauge wire. I checked it with a volt meter and it has 12v.

[Hugh Mongus]

I bumped the timing up to 16 degrees tonight, and installed a fuel pressure gauge. It is definitely running more pressure than I need. The needle bounces between 7 and 11. I will hunt down a pressure regulator tomorrow and install it.