[hddave1]

im working on a 350sbc crate motor with edelbrock 600 carb weiand intake.. stock cam.. i started out with a hesitation broblem so i changed needles and springs in carb as per advice from edelbrock support..the change fixed the hesitation but still idled rough so i set timing at 18deg btdc with vac advanced hooked up to full vac sourse while timing with light..its set at about 10deg. with dist. advance unhooked and pluged..still had a not so smooth idle so i pulled plugs.. the plugs where redish tan .. so i regaped to .050 per instructions from msd ..i started car again and it still had a irratical idle so i thought about checking the intake bolts and they where loose, i retighten them and start the car ,it runs worse now than before ..i pulled plugs again and the were black as coal sut..it spuuters now when you give it gas ... could it be the plugs are foaled now and if so what did i do wrone cuz it runs worse now that before i started ....im at a lose now and dont know what to do to get it right ....

[MI2600]

If you didn't touch anything else but the springs and metering rods, I'd switch back and see what happens.

[hddave1]

i also hear a ticing noise from either the dist. or the carb ..i know its not coming from the motor .. it sounds like a engine that needs plugs ..you can feel the miss in the gas peddle.. cant figure how the plugs got so black they werent when i first got started..after the needle and spring change i drove the car about 30 miles and it run fine it just had a slopy idle when in drive ..it never dies and always starts but now i can start it and it runs rough and i cant drive it...it misses somthing crazy

[DoubleVision]

The hesitation from the get go was likely a vacuum leak at the intake gaskets, when you tightened the bolts you may have cured it or slowed it down just enough for it to change the engine demands. Hesitation and rough idle are both signs of a intake leak. the timing should be set at 12 degrees btdc with the vac advance unplugged and capped, then reconnected to a manifold vac source after the initial timing is set. I'm guessing you installed the intake yourself, did you use fel pro gaskets? if so remember, the basic fel pros are not for aluminum intakes, they are for cast iron intakes that are heavy enough to crush them. If you have to replace the intake gaskets use the Mr. Gasket paper jobs hanging on the wall of almost any parts store. when the engine is new you always have to go back and check the bolt torque of the intake bolts, as they will always back out while the engine is seasoning in. drive it a few days, let it cool, check the bolts, do this once a week for about 3 weeks.

[hddave1]

what would cause the plugs to get black...would just tightening the intake bolts cause this...i will go back and reinstall the needles and springs that came out of the carb when new but the new needles and springs cured the hesitation...seems after i set the timing and tighten intake bolts that when my problem got worse

[Henry Highrise]

Its possible that you had your air fuel mixture set to compensate somewhat for the leaking intake....now you are running too rich and gasing your plugs it sounds like. Try adjusting your air fuel mixture on your carb and see what happens.

[hddave1]

well would i have to get new plugs or could i use what i have ..they have about 2300 miles on them ...

[F&J]

I would undo what you did to the carb. Then reset the float level on that POS edelbrock....I've never heard of one that was set correctly. ...and I HAD to set mine much LOWER that Edelbrocks specs.

I'm tossing mine asap for a quadrajet. Yea, I know they have their own issues ...like leaky well plugs..etc

The plugs are likely Ok if you can get the carb, possible vac leaks & ignition all working correctly, then run it 10 miles on the highway.

Aftermarket parts s---. JMO

[hddave1]

well i reset the timing to 10deg btdc which is the specs in the chevy book i have and as far as the intake leak , i did retighten them but i cant get to the back set of bolts unless i pull the dist. ...i hate to do it but i might just pull the intake all together and reinstall new gaskets and then lock tight the piss out of the bolts ..lord knows i use enough of that sh@#$t on my harley... i just cant figure the all of a sudden change in the way it runs..before i could drive it ...hell now cant take it up the street

[DoubleVision]

Think of it this way, when the intake is sealed, it only draws metered amounts and air and fuel from the carb, when a intake leak is present, it knocks the whole ball game off because air is entering from a outside source and the carb cannot compensate for it because its not metered, it makes the signal to the carb weaker. Since air is being pulled in from the outside, the fuel mixture from the carb is less, so lean mixtures, hesitation, lack of power are all side effects, when you richened up the mixture from the carb, and tightened the intake, it slowed down the intake leak so it was pulling a better signal from the carb and the new carb setting is too rich resulting in the issue you have now. This is about the easiest way I can explain it. Intake leaks on the inside of the intake can cause oil useage, blue smoking, and real lean mixtures that can get to the point the cylinder is running so lean it gets hot enough to burn a hole through the piston, if any header tubes turn white after a long drive its a dead giveaway.

[hddave1]

Originally Posted by DoubleVision

Think of it this way, when the intake is sealed, it only draws metered amounts and air and fuel from the carb, when a intake leak is present, it knocks the whole ball game off because air is entering from a outside source and the carb cannot compensate for it because its not metered, it makes the signal to the carb weaker. Since air is being pulled in from the outside, the fuel mixture from the carb is less, so lean mixtures, hesitation, lack of power are all side effects, when you richened up the mixture from the carb, and tightened the intake, it slowed down the intake leak so it was pulling a better signal from the carb and the new carb setting is too rich resulting in the issue you have now. This is about the easiest way I can explain it. Intake leaks on the inside of the intake can cause oil useage, blue smoking, and real lean mixtures that can get to the point the cylinder is running so lean it gets hot enough to burn a hole through the piston, if any header tubes turn white after a long drive its a dead giveaway.

well i changed the needles and springs back and it still idles really bad..you can feel it miss in the gas peddle and when the engine is just idleing it shakes. its not a smooth running engine at all at this point..if i put new intake gaskets in should i use the gaskets with the heat riser block offs..made by mr. gasket..thanks

[hddave1]

one more thing i regaped the plugs to .050.. they were set at .035 but i read that if using a msd ignition and dist that the plugs should be at .050 gap...could the gap in the plugs be a problem

[MI2600]

One clue to a vacuum leak is the engine will smooth out at higher rpm.

[carsavvycook]

Originally Posted by hddave1

im working on a 350sbc crate motor with edelbrock 600 carb weiand intake.. stock cam.. i started out with a hesitation broblem so i changed needles and springs in carb as per advice from edelbrock support..the change fixed the hesitation but still idled rough so i set timing at 18deg btdc with vac advanced hooked up to full vac sourse while timing with light..its set at about 10deg. with dist. advance unhooked and pluged..still had a not so smooth idle so i pulled plugs.. the plugs where redish tan .. so i regaped to .050 per instructions from msd ..i started car again and it still had a irratical idle so i thought about checking the intake bolts and they where loose, i retighten them and start the car ,it runs worse now than before ..i pulled plugs again and the were black as coal sut..it spuuters now when you give it gas ... could it be the plugs are foaled now and if so what did i do wrone cuz it runs worse now that before i started ....im at a lose now and dont know what to do to get it right ....

That explains your 16 inches maximum vacuum you had before. Now you will have to start from scratch on your tuning.

[hddave1]

yea, looks like im starting over..just my luck...i cant make my mind up to pull dist. so i can get to the last 2 bolts to see if there tight or just pull the intake and put new gaskets on...