Edelbrock Carburetor Troubleshooting

now we're going to talk about troubleshooting now if you happen to run into a problem with your carburetor before you take it off and bring it back to where you purchased it let's look at some of these issues you might be able to fix it without having to take it back now a number one problem that we run into sometimes is idling problems if you have any idling a problem where the air fuel mixture screws right here no matter which way you turn them don't do anything then it probably means that the idle circuit inside the carburetor is dirty now keep in mind to sustain an idle on an engine takes very very little fuel and air it doesn't take much at all and these are very small circuits inside here so any little minor piece of dirt that gets in there can plug that off and it's going to give you some idle problems so easy thing to do is just remove the air fuel mixture screws we'll take them both out just one at a time here it is you want to inspect it look for any dirt there's nothing on there I'll set that down and just take just a common airgun which is little air pressure go inside and just blow it out a little bit just like that and you do the same thing to the other one and that's just if there's any little minor dirt or fuzz or anything that got in there it'll just blow it through the circuit and then just reset this back in and screw it all the way in and don't cinch it but when it stops down at the bottom when it seats itself down back it back about a turn and a half or so there we go and not hard just just just seat it in back it back about a turn and a half and do that to the other one to pull it out blow some air in there and do the same thing and then start the engine up and then follow the procedure I told you earlier on how to adjust the air flow mixture screws and the problem should be gone now another problem you can troubleshoot is say the engine runs fine but you just can't get it to light or low enough all right well there's two three madhi's for that we can look in here here's the idle speed screw now by screwing it in it increases the idle and by screwing it out it decreases the idle and if that doesn't fix the problem if you look up under here there's another screw right down here now this is the high idle screw and what that is is while the choke is on this is what sets the fast idle for when the choke is activated when it's deactivated this really shouldn't come into play another problem some people run into is erratic idles like the engine idling high then low then high sometimes with even a whistle sound to it with that's indicating as a vacuum leak and a quick easy way to find vacuum leak is fire the engine up and try and get it to idle as low as you can then just take some basic carburetor cleaner and do a couple of short bursts of squirting around the carburetor just around the base plate area just a quick squirt and listen for the idle what happens is if you're sucking in air like stay on the base plate what will happen is this is volatile so it'll mix with the incoming air and actually increase the idle and you'll hear a definite idle increase so a spray around if you don't hear anything wait a second then come over here give it a little spray as the engine idles if there's a vacuum leak right there it'll suck this in and increase it by quite a bit then you know aha there it is right there and you'll give you an idea of an area to look for okay let's say the engine idles fine and runs actually fine just sitting here you can rev it up and no problems but you take it out on the road and under a load it pops and sputters or just doesn't have the power just can't get up and go with that's usually indicating is a lean condition while under a load and what you need to look for with something like this as a pinched off fuel line like maybe down at the fuel pump because what happens is the engine idling doesn't need much fuel and air to sustain an idle but under a load going down the road you're pulling off the main jets and you're flowing a lot more fuel and air through the motor so what that could mean is like I say a pissed-off fuel line it could be dirt in one of the main jets of the carburetor could be a piece of fuel line you might say well Aaron everything's new that I put on here a new fuel filter I put everything new well even inserting a new fuel filter sometimes can shave the inside of the hose and you get a little piece of rubber fuel line that goes on through and gets inside the carburetor and plugs off a main jet so even though it's new you could still have something in there another problem could be fuel pressure too low just inadequate so under a load you drain the float boils down and then there's not enough replenishment in the carburetor to keep it going so you want to check for things like that a problem you can run into sometimes the smelling fuel or actually seeing fuel around the carburetor especially coming out areas up on top of the carburetor like this these right here and this right over here are actually vents into the end of the float walls if fuels coming out of here or you can smell it or you can see it around the carburetor it's telling you there's a problem going on and what that problem could be is dirt in a needle and seat and with the needle and seat does is when the float level comes up and fills the float levels inside the carburetor it actually shuts the fuel off if you have dirt inside there it can't shut it off so the fuel pump just keeps pumping more and more fuel inside the carburetor it has no place to go so it comes out the top and gurgles all over the place it's a real fire potential hazard so you want to be sure that that problem gets fixed now another problem that could be is just a fuel pressures too high if you have too much fuel pressure then what will happen is it'll blow fuel right past that needle the seat it's not strong enough to hold back the fuel pressure so you never want any more than about 7 pounds of pressure going into the carburetor any more than that it's a little excessive these carburetors will handle a little bit more than that but you really don't need it so six to seven psi is pretty optimal for that now if you know your fuel pressure is good and you know there's no dirt and a needle and seat it could be just a simple float adjustment and you can take the top of the carburetor off flip it upside down and actually check the float levels with a scale or with a drill bit like a seven sixteenths drill bit and that will let you know if it's that the correct height they're not another problem you can right in - sometimes is let's say the engine runs just fine normally but you got a little bit of a high and erratic idle but not too bad which is a little high erratic idle and another symptom you find is when you're cruising down the road and just give it a little bit more throttle you get a pinging sound now what that's telling me is you probably have a vacuum advanced and chances are that vacuum advanced is hooked up to the wrong vacuum port on the carburetor and what I mean by that or most vacuum advances use ported or timed vacuum and if you hook the evacuate advance up to manifold vacuum it'll do exactly this it'll pull too much advance at an idle because it's running off a manifold vacuum and when you're cruising down the road and you give it just part throttle it'll ping so what we want to do is look at the vacuum ports down here one is low and one is high now the lower one down here is manifold vacuum an easy way to tell is fire the engine up and stick your finger on it manifold vacuum and suck your finger on it ported vacuum our time vacuum really want there's almost no vacuum in an idle most vacuum advances used this side right here now problem you can run sometimes after you install a new car or even a new intake manifold is the engine running really really high idling high and you can't get it to idle down without it stalling and dying out on you now usually what that means as you left the plug under the backside of the carburetor that we usually use for like power brake port or something like that also sometimes in the intake manifold if you put a new one on if you didn't put a plug in there you have a direct open vacuum port right there and what that'll do is also cause it to idle really really high and no matter what you do as soon as you start getting it to idle down a little bit it stalls the engine so look around the back side of the carb look around the intake manifold for plugs that are left out or anything like that and I probably solved the problem ok let's say you just installed a carburetor now you're having trouble with your automatic transmissions shifting like it doesn't want to shift until he hits a real higher rpm or a does shift it's damn real hard what that's telling you is either the vacuum line going down to the modulator valve on a transmission is either pinched or it's split or it's not plugged into the proper port on the carburetor here so you want to be sure is that that is having manifold vacuum if we look at the carburetor that's this port on this side right here it's the lower port that sits lower on the carburetor this one's slightly higher this one's slightly lower again if you stick your finger over it should suck your finger on there that's the one that should go down to the transmission if it's hooked up to that your transmission is just if properly now the problem some people run into sometimes they put a brand new carburetor on it runs great for a few days then all the sudden it really starts running bad now usually the culprit behind that is someone didn't install a fuel filter the reason this takes a couple of days to do is you've got microscopic particles in the fuel tank you got them in the fuel lines you got them in a fuel pump and it takes a couple of days for these little particles to start accumulating and work their way inside the carburetor then once they get in the carburetor it takes a couple of days to start accumulating and filling up the main jets and pretty soon you clogged one up and then the carbon doesn't run very good so if you install a fuel filter which is very important to do you should eliminate problems like this now some people can run into problems on large cubic-inch engines where you're driving down the road and you give it a throttle and you have a hesitation okay only when you first give it the throttle now what that usually is is the accelerator pump and that's located right inside the carburetor here and what that is that's a plunger so every time you give it throttle you'll see this linkage move and what that does is that squirts fuel inside the carburetor that's an initial squirt of fuel before the main jets work well there's some adjustments on the linkage right here so you can make it you have a bigger squirt or a smaller squirt well on larger cubic-inch engines you need a bigger squirt of fuel and a smaller cubic inch engine you need a smaller squirt of fuel but what this will do when this is not working properly is it will run fine cruising but when you first get it throttle AHA and you'll have a hesitation and what that first little hesitation is is usually the accelerator pump so you want to check that right there a problem you can run into sometimes is what's called an off idle surge and what that means as wide as you come off of an idle and you're starting to go or you're cruising along just barely over an idle the car wants to surge a little bit now usually that means on the idle mixture screws you're a little on the lean side or possibly a little on the rich side so you can go back and readjust those just a little richer a little leaner and that should make the problem go away

Channel: Auto Shop Videos

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Keywords: edelbrock carb, how to adjust edelbrock carb, how to install edelbrock carb, edelbrock carb problems, edelbrock, auto shop videos, autoshopvideos, bad ass cars, arron johnson

Id: OeD1UCnDHF8

Length: 11min 48sec (708 seconds)

Published: Mon Nov 30 2015