Engine Stalls out in any gear HELP

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JeffreysDart

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Hi Guys,
Newly Built 318 with performer intake and stock heads, stock cam and other stock parts, pistons etc in a 67 cuda with a 904 trans. Timing is set and runs great on idle. When put into ANY gear car will bog down and stall. Give it gas and it will stay running. Never have had this happen before. My current guess is its the carb because i bought it off some dude and its been used and who know whats been done to it. Its an Eddy 500 1403.

So buy a new carb? or any other potential items to look for?
 
I'm guessing something in the ay the carb is set up. Any vacuum leaks? I wouldn't buy new just make sure its set up maybe clogged passages or something.
 
Sounds like a problem in the idle circuit of the carb... Get a rebuild kit and blow out the idle passages real good with carb or brake cleaner and compressed air....
 
Have you put a vacuum gauge on the carb base?
What is the timing set at?
 
Hi Guys,
Newly Built 318 with performer intake and stock heads, stock cam and other stock parts, pistons etc in a 67 cuda with a 904 trans. Timing is set and runs great on idle. When put into ANY gear car will bog down and stall. Give it gas and it will stay running. Never have had this happen before. My current guess is its the carb because i bought it off some dude and its been used and who know whats been done to it. Its an Eddy 500 1403.

So buy a new carb? or any other potential items to look for?
Remove the idle mixture screws and blow the idle passages out with carb cleaner (cold engine) reinstall the screws, seat them very lightly not to damage the needle end and/or seats and set them 1 and 1/2 turns out for the initial setting.
After you start the engine warm it up to operating temp, check to make sure the choke is wide open and set the screws to highest intake manifold vacuum using a vacuum gauge. Using the idle speed screw set the idle to around 800 rpm.
Look at some utube videos before you proceed.
 
Exact same thing happened with my son's 360. Ended up being a vacuum leak at carb/ intake gasket. It would idle fine and then stall in gear unless you gave it a good shot of gas to take off. It still ran like crap but you could drive it by feathering the gas pedal at a stop light ect.
 
Does it have any miles on that new rebuild yet?

yes vacuum leak or carb trouble. Do you have a known good carb to put on it?
 
What is the idle rpm? Too low in neutral & it could stall when going into gear & rpm drops further.
Try backing out the idle mixture screws 1/4-1/2 turn.
 
I love guys who say
Timing is set and runs great on idle.
but never give a clue as to what the "set" is or their definition of "runsgreat".

Here is your clue; Your 318 will run great (lol) with the more Idle-Timing you give it, even with timing into the mid to high 20s. So running great is a given, as long as the carb is half-decently adjusted, and the low-speed circuit is working.
Stalling when going into gear is almost always caused by just one thing; The TC pulls the rpm down suddenly, and the sudden drop in airspeed thru the carb causes a loss of fuel delivery.
Your stock 318 will idle down to 500 at your elevation, happily plugging away. But the throttle-blades will have to be fairly accurately synchronized to the transfer slots, so that they don't dry up at idle.
So do this for starters;
> make sure your Vcan is plumbed to the spark-port and is not calling for any timing, at idle.
> make sure your PCV is plumbed correctly and working. It should be delivering air to the FRONT of the carb, to just below the throttle blades.
> If you have Power Brakes, make sure the supply line is not sucking air, by just temporarily clamping it off.
> If your intake has provision for EGR, make sure it is NOT working at idle
> make sure the secondary throttles are 100% closed but not sticking; You will have to pull the carb off and shine a light up from the bottom to prove that they are BOTH fully closed.
> if you have adjustable valve gear, set the lash to .013 intake/.023 exhaust. COLD (room temperature, not 20* below,lol.
While the carb is off;
Reset your idle speed screw so that the T-slot exposure beneath the throttles is about exactly square, and the same on both sides. Then Reset your mixture screws to 2.5 turns out from lightly seated.
Now, re-install the carb.
Fill the fuel bowl thru the vent.
Then start it up, and warm it up.
DO NOT TOUCH the speed screw. Let the idlespeed be whatever until the coolant temp comes up to speed.
With an IR gun verify that the coolant temp came up to between 180 and 200, then
reset your timing until the Idle-speed in gear is somewhere between 550 and 650 tops. Put it back into park.
Now go fiddle with the mixture screws, looking for best-QUALITY idle.
If you find that this is NOT 2.5 turns plus or minus 1/2 turn, then
A) if it is less than 2.0, then the engine is getting a tad too much Idle fuel from the Transfers. ASSUMING the fuel level is correct, reduce the speed screw setting by 1/2 turn, put the mixture screws back to 2.5T, and fiddle some more.
B) It you find the mixture screws run best at 3.0,then the engine is not getting enough fuel from the transfers, so increase the Speed-screw setting by 1/2 turn, reset the mixtures to 2.5T and fiddle some more.
C) repeat up to two times.
D) open the mixture screws 1/4 turn richer.
Reset the in-gear idle speed to between 550/650 tops, as before, using Idle-Timing.DO NOT TOUCH the speed screw.

Now you are baselined

Two things this should immediately do for you. 1) the engine should no longer stall going into gear and 2) the engine should not have a tip-in problem. That is to say, once in gear, as you very slowly tip-in the throttles, the car should happily motor away, with no stumble or hesitation.

Now; If the in-gear to in-Neutral speed difference is more than 100 to 150, then SOMETHING IS WRONG. Depending on how great the difference is, it could be nothing but a minor vacuum leak, or it could be a failing TC, or your engine may have a chamber-sealing issue. IE the valves are not sealing properly.
So if this happens to you, you will have to hunt it down. I humbly suggest you start with a LeakDown test.

Next; so far we have not paid any attention to the actual Idle-timing number!
Now, after the engine is idling happily with no more issues, now is the time to check what it actually is.......
Because the rest of your Power-Timing has to be based on this number.
If the Idle-timing ends up being LESS than TDC, something is wrong.
If the Idle-Timing ends up more than 20*, something is wrong!
It should fall between 5*advanced and ~15 advanced with
a target around 8 to 10 degrees advanced.
But it really does not matter what the actual number is, if the engine is responding well to throttle inputs. The very FIRST time that timing matters to your engine is at stall-rpm, and the last time it cares is at "all-in" rpm. You the tuner, have to determine those points and by experimentation, max out the timing within the constraint of the engine NOT detonating with the Gas you are attempting to run.
Generally, MSBs run best with Power-Timing of ~34/36*, all in as early as 3400rpm (later is fine); let that be your guide.

BTW-1
You cannot optimize the idle-timing; it is impossible to do without a feed-back timing computer, So don't even try.
While cruising, say at 2400 rpm in top-gear, you might find that the engine wants 45 to 55 degrees.
In Neutral, she might like hi 20s to hi 30s. Do not go there; your carb cannot go there. The transfers are your primary low-speed fuel delivery circuit, with the mixture screws just being idle-trimmers. The higher your Idle timing, the more closed your throttles will need to be to keep the idle-speed down, which dries up the transfers.... or at least, slows them right down. So you can get it to idle that way..... but just try to drive it like that. Every time you lift enough that the throttles come to rest,, the car will tend to nosedive, and then, when you tip the throttle back in, ...... wait for it, here they come, the transfers are starting up; one-elephant, two-eleph, tada here they are. In the meantime, it feels like someone interrupted the ignition. Then when it restarts, your timing is advanced enough, and your foot is deep enough into the carb, that when the engine springs back to life,
your poor neck-snapped wife blames it on you and refuses to ever ride with "you maniac" again. Ok maybe that last part only ever happened to me......
BTW-2
there is a simple easy way to prove all this;
Just crank the speed screw in for a gain of 50 to 100rpm, reset the mixture screws to 2.5turns, then take timing out to drop the rpm back to the starting point; now try it.
 
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