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How To Adjust 454 1983 Carburator?

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blackandgold51

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The other day the 454 was running rough until I sprayed some Carburater and fueal injector cleaner and it cleared up some last night during idle.

I sprayed some more of almost two cans and this morning I started it up and the motor started to knock. I checked the oil and added some oil just in case the knock cleared up and the motor sounded rough and rough while taking the the vehicle around the street.

I already changed the fuel filter and I'm wondering if it's the fuel pump going bad or the Carburater needs adjustment.

I opened the 2 top barrel butterflies while idling and the rpm went up some with clear idle and while playing with the trottle cable some

After letting go it idled down and sound rough.

I'll make a video and post it when I head to the library this evening
 
What are you describing? Spraying an aerosol can of carb cleaner past the choke blade? Are you doing this with the engine running or off? If the idle circuit is blocked, it's unlikely you'll clear it with superficial methods since the idle circuit is so convoluted. When these get bad you typically have to tear the carb down and clean those circuits out with tiny strands or compressed air. A solvent in the fuel could break down varnish and such, but if you have a speck of crud in one of those tiny passages it needs to be removed mechanically.

Generally running issues could be attributed to a bad fuel filter or pump, but for idling, you either have fuel in the bowl or not. The fuel is sucked through orifices by intake air, not forced in any way by fuel pressure. Before taking anything apart, go back over the basics. Is the choke blade opening? If it was running fine and now seems bad under all conditions, I would suspect an ignition problem more than carb. If the exhaust smells like fuel, this can be either a carb or ignition problem.
 
Blue85 said:
What are you describing? Spraying an aerosol can of carb cleaner past the choke blade? Are you doing this with the engine running or off? If the idle circuit is blocked, it's unlikely you'll clear it with superficial methods since the idle circuit is so convoluted. When these get bad you typically have to tear the carb down and clean those circuits out with tiny strands or compressed air. A solvent in the fuel could break down varnish and such, but if you have a speck of crud in one of those tiny passages it needs to be removed mechanically.

Generally running issues could be attributed to a bad fuel filter or pump, but for idling, you either have fuel in the bowl or not. The fuel is sucked through orifices by intake air, not forced in any way by fuel pressure. Before taking anything apart, go back over the basics. Is the choke blade opening? If it was running fine and now seems bad under all conditions, I would suspect an ignition problem more than carb. If the exhaust smells like fuel, this can be either a carb or ignition problem.
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Ok. I posted a video on this thread check it out if you didnt
 
You may have loosened some carbon up in the cylinders and piston tops,and it could have fouled a spark plug or two by spraying carb cleaner down the intake..
 
The distributor cap and wires look kinda old too--might not hurt to check the cap for cracks or corroded terminals inside and where the plug wires go in it..
 
diesel4me said:
The distributor cap and wires look kinda old too--might not hurt to check the cap for cracks or corroded terminals inside and where the plug wires go in it..
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I check a few of the spark plugs and they had gunk on them as of now I'm changing all the plugs with AC delcos
 
diesel4me said:
The distributor cap and wires look kinda old too--might not hurt to check the cap for cracks or corroded terminals inside and where the plug wires go in it..
Click to expand...

While at AutoZone, after I did all the plugs I had I guy I know at AutoZone look at it while it was operating . He said it's a heavy vacuum leak
 
An exhaust leak won't affect idle,but an intake leak (vacuum) will..
I'd be sure the base gasket under the carb isn't letting air sneak under it,they do fail --spraying carb cleaner around the base where the gasket is with it idling will reveal a leak,you'll hear the rpms change--be careful not to spray any at the top of the carb or on any of the plug wires..(also a bad plug wire may be the culprit,sometimes headers will burn them or an exhaust leak burns the insulation off and lets it short out to ground..)

An EGR valve that is not closing completely at idle will make a vacuum leak and a poor idle will result...a clogged up PCV valve or it's hose and port it hooks to at the intake can cause it also..

The carb may now have some crud in it that loosened up when you sprayed it too..there is so many things that can cause a rough idle it is about impossible to guess at which thing it might be over the internet..
 
diesel4me said:
An exhaust leak won't affect idle,but an intake leak (vacuum) will..
I'd be sure the base gasket under the carb isn't letting air sneak under it,they do fail --spraying carb cleaner around the base where the gasket is with it idling will reveal a leak,you'll hear the rpms change--be careful not to spray any at the top of the carb or on any of the plug wires..(also a bad plug wire may be the culprit,sometimes headers will burn them or an exhaust leak burns the insulation off and lets it short out to ground..)

An EGR valve that is not closing completely at idle will make a vacuum leak and a poor idle will result...a clogged up PCV valve or it's hose and port it hooks to at the intake can cause it also..

The carb may now have some crud in it that loosened up when you sprayed it too..there is so many things that can cause a rough idle it is about impossible to guess at which thing it might be over the internet..
Click to expand...
A couple of months , that i remember, had the same thing happened when the engine was having less acceleration power and less idle due to the exaust header leak and loud tapping noise.

I brought the vehicle to my buddies shop where he does exhaust and mufflers, I had them wealed the headers with me gaskets and te noise was gone and power was back up while the motor had smooth idle.

However they suggested that I get new headers soon due to the current headers that are almost rust rotted
 
diesel4me said:
An exhaust leak won't affect idle,but an intake leak (vacuum) will..
I'd be sure the base gasket under the carb isn't letting air sneak under it,they do fail --spraying carb cleaner around the base where the gasket is with it idling will reveal a leak,you'll hear the rpms change--be careful not to spray any at the top of the carb or on any of the plug wires..(also a bad plug wire may be the culprit,sometimes headers will burn them or an exhaust leak burns the insulation off and lets it short out to ground..)

An EGR valve that is not closing completely at idle will make a vacuum leak and a poor idle will result...a clogged up PCV valve or it's hose and port it hooks to at the intake can cause it also..

The carb may now have some crud in it that loosened up when you sprayed it too..there is so many things that can cause a rough idle it is about impossible to guess at which thing it might be over the internet..
Click to expand...
In the case of the intake manifold I'll go ahead and change the intake manifold to a high flow manifold.

I did spray carb cleaner while vehicle was idling and the rpm raised a bit dmthen goes down while spraying o top of the carbCarbur
 
Update: today I hear some screeching sounds which was coming from the belt . A of now I'm looking at the belt on the 454 that does not connect to the alternator that is worn, ,although the other night I noticed the lights going "brighter" when at high rpm while there was a a screeching sound.

I'll chanhe he althernator and see if the alnternator is worn since I got a spare one
 
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