Need help adjusting carb, idles high in part and too low in gear
I need help adjusting the edelbrock carb on my s10,it idles kinda high, around 1300-1400, and when in gear can drop low, to the point of stalling some times. I do not know anything about adjusting Edelbrock carbs other then the idle metering. And I haven't even checked the timing yet. I already have advice from another member on the timing, and will check it Saturday..
Where should I start? It runs strong, its just a high idle and gets too low once in gear. I couldn't find any vacuum leaks.
A little info on the 350 below
It's got a 355 with flat tops, mild worked 882 heads, solid flat tappet cam (cam card below), victor jr 4+4, edelbrock 750, long tube headers, 3800 stall, stock TH350, 10 bolt rear with 3.73 and Lincoln locker. 28.5/10.5 slicks.
(yes I know this motor needs heads and a lot more compression)
Was told it has to be tuned different if the motor has a lot of duration.
Lock out the distributor mechanical advance curve. Set the now fixed locked out timing to 36deg BTDC.
Now reset the carb. It will idle around 1000 rpm. use a 3" or 4" rated power step up spring in the carb.
This cam need a full 36deg locked idle timing to idle correctly with a auto trans.
Get some 4.56's
Hint: instead of trying to "Hot lash" the valve lash set it cold at .022" instead of .026" hot.
Sounds good, I will check that Saturday as well. Thank you for the help, that way I know what I'm after when I work on it Saturday.
I am a little confused on the power setup spring though.
I'm going to keep an look out for a Holley. looking at a 750 vac sec, but if I find a good deal on a double pumper would that work too? It won't be on the street except to go to the gas station
Big cam ='s low manifold vacuum at idle. You want the primary metering rods to stay down lean at idle.
Therefore a low 3" 4" power step spring. Similar to holley power valve selection.
The distributor will need to be locked out with either carb. The edelbrock carb will work fine once the distributor is corrected.
This is the nature of these big racy cams.
edelbrock carb tuning
Volvord 784VC Edelbrock Carburetor
Don't bother with a vac sec carb.
Ditch the 882 heads before spending any money on any other parts.
They are your major performance/power cork.
A nice upgrade
I was told if I lock out the distributor I will have to run a toggle switch in between the power wire on the coil, and when I start it I turn the motor over then flip the switch to apply power to the coil or it will kick back.
I use to race Dirtbikes I know how bad kickback hurts. I keeping and eye out for heads, a new rear end hearer lower and a carb, might be a few months though.
Would this switch be needed? I love the cam in this truck, it's well worth the extra hassle.
With that much duration, you may not have any kickback. Try it first and see what happens.
Yes a ignition power interupt switch will allow hot starting without kick back, and drama.
Where it goes depends on the ignition system used.
GM HEI it goes on the big pink HEI 12v+ power wire. 15a rated SPST toggle.
MSD 6 or similar CD box it goes on the small red power switch on wire that controls the box.
Also be sure the GM OEM starter motor brace is installed.
It is a required item
if yours is missing, get one.
It doesn't have the brace, I will order one online (hopefully flea bay)
can I unhook the vaccum advanced or do I need an adapter to hold the bar inside the dristributor in a certain spot?
They don't make plates to lock the distributor on a hie do they? I can't find one. Can I take a thick feeler gauge, mark it, drill it, and use the original e clips to hold it on.
I'm researching this as much as I can, even ran into this :-)
Thanks for the help answering my noobie questions
Crane Cams #99600-1 Adjustable Vacuum Advance Kit is what I think you need.
I have one here, and the limiter plate is included in the kit as per the above picture. It looks like Summit also sells JUST the limiter plate ... #99619-1
I made a plate to lock it.
Can I just unplug the vaccum line for the advance or do I need to replace it with something.
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