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Help tuning a big block 350 w/ edelbrock carb

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Old February 17th, 2012, 8:09 PM
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Default Help tuning a big block 350 w/ edelbrock carb

Hi. I know this probably isn't the right place for this question, but anyways here goes.

I have a rock crawler that is a Toyota body on a 1/2 ton chevy frame with a 350 in it. I actually traded a dirt bike for it, lol, but its a cool truck and I'm having fun with it. I'm a single mom, and it gives me and my son something we can both have fun with. (He named it Mater!)

I don't know much about big block motors, or about tuning carbs. It is a reman engine, and has a 600cfm edelbrock carb on it. I did notice the choke has a cable coming off it that just dangles in the cab, that may be part of my problem.

The truck starts easy when its warm, but I have to pump hell out of it and hold the gas a while to get it to stay running when its cold. Would an electric choke fix that or does that sound like more of a tuning issue?

Also, no matter if the engine is warm or cold, it hesitates badly at partial throttle, acts like it wouldn't even make it up a slight incline. But if play with the pedal enough it will find its sweet spot and take off. Or if I just give it like 3/4 pedal it will bog and eventually pull itself out of it and start moving.

Any assistance with how to tune this thing or check potential problems would be MUCH APPRECIATED!!! Thanks in advance!
Old February 18th, 2012, 4:37 PM
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Sounds like you should take off the Edelbrock carb and put a holley truck avenger carb to solve that issue. I have had good luck with Holley carbs forever. There should'nt be a cable hanging off the choke in the carb. By the way a Chevy 350 is a small block not a big block. Good Luck getting things working properly.
Old February 20th, 2012, 9:10 AM
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Ya get rid of the edelbrock carb, go with a holley, and dose it have hesitation going up hill? I've just recently built a rock crawler now I'm starting to build a new one would be interested in seeing a picture of the truck
Old February 21st, 2012, 7:31 AM
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It just feels like it has no power, like it might not even have the guts to get up the hill. I pulled a plug on each side, and one side was fuel fouled, the other side looked burnt, so I adjusted the carb screw on the burnt side out one full turn, then turned them both back about 1/4 turn. I think that whoever adjusted the carb initially must have not turned the screws the same amount out. I'm waiting on a new set of plugs to run the truck and see what kind of difference that made. I'm also buying an electric choke.

Here's a pic of my son in it. He loves the truck, named it Mater lol.
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Old February 21st, 2012, 11:27 AM
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Sounds like a vacuum and/or a timing issue, carb might need some fine tuning. Get a vacuum gauge and read THIS. Do you know how to use or have a timing light? Do you know the Carb Model? The manuals for the Edlebrock carbs are available online, there is usually a base setting of 1 1/2 turns out on the screws.

To check for vacuum leaks, see THIS

Here is an article on Setting carb idle with a tach and vacuum guage, see THIS

Manual choke is fine, you just need to get a bracket and handle and repair it, or if you live in a warm climate, you do not need it. You can buy kits at any auto store.

Nice truck!!!
Old February 22nd, 2012, 7:19 AM
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I can't remember the model #, but it is 600cfm. I think I have the screws turned out about 2 1/2 turns now, I was compensating for the open air breather and the high flow exhaust. I do have a timing light but I'm not totally sure how to use it, I will invest in a vacuum gauge. Thank you for those links, they will help alot!
Old February 23rd, 2012, 7:19 AM
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I have never had good luck with edelbrock carbs, just from personal experience, I would def check for a vacuum leak and if there isn't a timing issue or a leak then switch out the carb with a Holley
Old February 23rd, 2012, 11:54 AM
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I have had nothing but great luck with Edlebrock in the past, no need to swap carbs unless this one is defective, just needing properly adjusted or rebuilt is no reason to trash a perfectly good carb.
Old February 23rd, 2012, 10:50 PM
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I think these guys got you covered with the vacum leak. but me and a friend just started building on of those and thats exactley what i want it to look like but hunter orange. this is kinda off subject but what size are those super swampers. and i dont think it would cause any mayjor problem but is that a good size ding in the header tube second if your looking from right to left?

Last edited by nkh34; February 23rd, 2012 at 10:53 PM.
Old February 24th, 2012, 7:39 AM
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Thanks for the input, I'm going to check for vac leaks this weekend if the weather will be decent for me. Are there any particular problem areas I should pay special attention to?

I think the carb is fairly new, so it shouldn't be needing a rebuild, I guess I don't know enough about them to know whether its a bad one or not, but my dad just put an edelbrock on his old chevy and its running pretty good with it. I guess I don't have enough money to just buy a different carb if there is nothing wrong with this one, so I'll just have to work with what I got.

Those tires are 35's, and yeah that is a big dent in the header, but its not cracked or anything, I don't think that would be causing any problems, but you never know I guess?


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