Bulldogchesty1
New Member
What would keep my 383 stalling trying to put it gear, it is warmed up enough. Just keeps stalling. Holley carb.
Stalls in gear:
- Thread starter Bulldogchesty1
- Start date
Does this happen randomly or consistently? Does this happen before or after the carb comes off of fast idle? Hot base idle speed adjusted to factory specs or lower? Will the car restart quickly after it stalls? Orig Holley 4bbl or a replacement Holley?
When it stalls, does it still have "shot" from the accel pump? Any seeps from the lh frt lower corner of the carb onto the intake manifold?
Original fuel pump pushrod?
Just curious,
CBODY67
When it stalls, does it still have "shot" from the accel pump? Any seeps from the lh frt lower corner of the carb onto the intake manifold?
Original fuel pump pushrod?
Just curious,
CBODY67
We will need a little more information to help. What is your idle speed and what is your timing set at are a couple questions that come to mind. It could be the engine in not idling with enough power, it could be a bad converter but that is not likely.
Bulldogchesty1
New Member
Idle speed is set to about 900 rpm. don't know the timing offhand.
900 seams a little high to me for a stock engine. If you back the idle down to 800 does the engine stall? If so that also points to timing or ignition or an improper adjusted carb. I have found that timing can be an issue with stalling going into gear. The timing effects the power and the timing might be just enough for the engine to start and run but doesn't have any power so when you drop it into gear it is just enough to kill it.
Two things you need to know to get an engine to idle with power; ignition timing, manifold vacuum. Set timing first at the correct idle speed then adjust your carb idle mixture screws (they are on each side of a holley carb) to get the most vacuum you can get. As you make the adjustment your idle circuit screws your idle speed may change, so set the max vacuum then reset you idle speed.
Here is just one article that walks you thru it.
www.dragzine.com
Two things you need to know to get an engine to idle with power; ignition timing, manifold vacuum. Set timing first at the correct idle speed then adjust your carb idle mixture screws (they are on each side of a holley carb) to get the most vacuum you can get. As you make the adjustment your idle circuit screws your idle speed may change, so set the max vacuum then reset you idle speed.
Here is just one article that walks you thru it.
How To Properly Adjust The Idle Mixture On Holley Carburetors - Dragzine
Is your Holley carburetor stumbling or stalling on idle? This helpful guide will get you back up and running in no time with the perfect idle.
www.dragzine.com
One question might be WHY the hot base idle speed is set that much more than a normal 600-700rpm idle speed? Is it set that high to keep it running or just somebody's idea of what it needs? OEM vac advance should be "ported", too.
CBODY67
CBODY67
Bulldogchesty1
New Member
I have it higher to keep it running.
IF it will not reliably idle at lower rpms, there could be something restricted in the primary metering block, if the idle mixture screws are adjusted correctly for the slower speed. Holley does sell some of those primary metering blocks, but it might well be that a new complete carb might be needed. In which case a new Carter/Edelbock AVS2 would be a good option for the future. Electric choke model.
CBODY67
CBODY67
Vacuum leak
Retarded timing
Crossed plug wires
One or some cylinders not firing
Fouled plugs, either from carb problems or oil fouled
Carb mixture problem so the engine can't take any load without dying.
What is the Holley? Factory piece or aftermarket?
Retarded timing
Crossed plug wires
One or some cylinders not firing
Fouled plugs, either from carb problems or oil fouled
Carb mixture problem so the engine can't take any load without dying.
What is the Holley? Factory piece or aftermarket?
I say start with the easiest first. Set your timing at whatever it will idle at, then try to get in to idle down to 700, if it will recheck the timing and adjust if needed. Then hook up that vacuum gauge. Most automotive vacuum gauges have colored markings on them that show normal in green, if it is in the low range you could have a vacuum leak, if it is bouncing all over you could have a bad valve, or sticking one. But start with timing, hook up that vacuum gauge and try to set the carb per the Holley instructions in the link I sent you. You will know if you have a bad idle mixture circuit if the vacuum gauge doesn't change when you are adjusting it. If that doesn't work and you can't pull normal vacuum then start diagnosing your ignition system (wires, plugs, mixed up plug wires). 9 times out of 10 when you set that timing and adjust the carb you will be all set. It's that tenth time that separates the men from the boys. lol
Good luck and report back, good or bad. I hate it when the advice we give fixes a problem and the OP never reports back.
Good luck and report back, good or bad. I hate it when the advice we give fixes a problem and the OP never reports back.
How long has it been necessary to elevate the hot base idle speed? Something that happened suddenly or came on gradually? THAT might help indicate where the issue is.
"Crossed plug wires" don't happen by themselves, needing help by an installer. "Vacuum leaks" can happen by themselves, though, which alone can cause leaner mixtures, but seldom enough to seriously alter idle quality. A little rougher, but not to the level of a full miss.
"Retarded ign timing" normally does not happen by itself, but worn ignition points CAN affect ign timing.
"Fouled spark plugs" usually don't fire well, if at all. Resulting in a miss on that cyl. They normally don't happen quickly, but gradually, until they foul enough to not fire. Sometimes the plugs are just loose and can't make a good ground for the ign voltage to reach "ground". Sometimes due to spark plug wire failures/cracks that leak voltage "to ground" before the voltage can get to the spark plug.
When a spark plug that does not fire is removed, it will be obvious. The spark plug gap area will be covered in the fouling-deposit material, be it oil or gas. Running a gap gauge through that gap, to clean it off, can then make it fire again, YET a new plug is the best way to do things.
Many things MIGHT cause the issue the OP mentioned, but as "elevated idle speed" was all that was mentioned, we don't yet know if idle smoothness (which can relate to stalling) is an issue, OR if there is not enough idle fuel to support ANY idle activities.
Reason I know this is because I had a similar issue with the BBD on my 1980 Newport 360. It would act just fine when started, but as soon as the engine got warm enough to not be on fast idle, it would die. As long as idle speed was elevated, it would run and drive normally. But take my foot from the accel pedal to slow down for an exit ramp, it'd die at 60mph. Always restarted and ran as long as it was not using the idle circuit.
I rebuilt the carb, using spray B-12 to clean it and check for "flow" through the idle tubes. I could restart the engine and it would idle at the normal hot base idle speed . . . UNTIL all of the solvent in the idle tubes was depleted and then it would die. I kept seeing a spec for "Low Speed Jet" in the carb specs, but did not know where it was until I finally found it in an obscure place in the service manual illustrations. On that carb, it was in the bottom of the idle feed fuel tube. On a Holley 4bbl, it's in the metering block as "Idle Feed Restriction", and sealed. Unlike the Carter BBD, the channels leading to and from that IFR are not straight.
I got a bent-wire spark plug gap gauge and started to probe that recessed hole. Starting with the smallest size, each probe resulted in hard deposits breaking away. Finally I reached the largest size that would fit the hole and then I went in search of a "twist drill" selection at a hobby shop. With that finger/twist drill set, I went through the assortment until one size "hit brass", which is the size I used to enlarge the existing drilled orifice to. Cleaned out the residue with spray carb cleaner. That was the end of my problems with that carb. 4bbl Carters/Edelbrock 4bbls have similar idle circuits, but Holleys have the IFR for the same function. NOTE . . . "Hard Deposits" built-up in those passages, which carb cleaners/soak solutions would NOT remove, which is why I had to remove them mechanically!
So, as I had a Carter carb, I had to remove the hard deposits mechanically with a drill bit of appropriate size. Holleys will need a new primary metering block. Yes, there are provisions to change the IFR dimension, but it takes drilling out the seal plugs, modifying the IFR size, then re-sealing the plugs. More recent Holleys have screw-in "jets" to do the same function, in the primary metering block.
Holley 4bbls also have an idle circuit related to the secondary throttle bores, with an incognito set screw which adjusts how far open the secondary throttle bores are at hot base idle. Many are unaware of these things as they are not seen unless the carb is apart. The reason they are hidden is that they are NOT to be adjusted after the carb is originally assembled on its assy line. That little bit of idle fuel flow through the secondaries is supposed to keep the fuel in the secondary float bowl "more fresh" than not. Even if the vacuum secondaries remain closed all of the time.
Until we get more information from the OP . . .
CBODY67
"Crossed plug wires" don't happen by themselves, needing help by an installer. "Vacuum leaks" can happen by themselves, though, which alone can cause leaner mixtures, but seldom enough to seriously alter idle quality. A little rougher, but not to the level of a full miss.
"Retarded ign timing" normally does not happen by itself, but worn ignition points CAN affect ign timing.
"Fouled spark plugs" usually don't fire well, if at all. Resulting in a miss on that cyl. They normally don't happen quickly, but gradually, until they foul enough to not fire. Sometimes the plugs are just loose and can't make a good ground for the ign voltage to reach "ground". Sometimes due to spark plug wire failures/cracks that leak voltage "to ground" before the voltage can get to the spark plug.
When a spark plug that does not fire is removed, it will be obvious. The spark plug gap area will be covered in the fouling-deposit material, be it oil or gas. Running a gap gauge through that gap, to clean it off, can then make it fire again, YET a new plug is the best way to do things.
Many things MIGHT cause the issue the OP mentioned, but as "elevated idle speed" was all that was mentioned, we don't yet know if idle smoothness (which can relate to stalling) is an issue, OR if there is not enough idle fuel to support ANY idle activities.
Reason I know this is because I had a similar issue with the BBD on my 1980 Newport 360. It would act just fine when started, but as soon as the engine got warm enough to not be on fast idle, it would die. As long as idle speed was elevated, it would run and drive normally. But take my foot from the accel pedal to slow down for an exit ramp, it'd die at 60mph. Always restarted and ran as long as it was not using the idle circuit.
I rebuilt the carb, using spray B-12 to clean it and check for "flow" through the idle tubes. I could restart the engine and it would idle at the normal hot base idle speed . . . UNTIL all of the solvent in the idle tubes was depleted and then it would die. I kept seeing a spec for "Low Speed Jet" in the carb specs, but did not know where it was until I finally found it in an obscure place in the service manual illustrations. On that carb, it was in the bottom of the idle feed fuel tube. On a Holley 4bbl, it's in the metering block as "Idle Feed Restriction", and sealed. Unlike the Carter BBD, the channels leading to and from that IFR are not straight.
I got a bent-wire spark plug gap gauge and started to probe that recessed hole. Starting with the smallest size, each probe resulted in hard deposits breaking away. Finally I reached the largest size that would fit the hole and then I went in search of a "twist drill" selection at a hobby shop. With that finger/twist drill set, I went through the assortment until one size "hit brass", which is the size I used to enlarge the existing drilled orifice to. Cleaned out the residue with spray carb cleaner. That was the end of my problems with that carb. 4bbl Carters/Edelbrock 4bbls have similar idle circuits, but Holleys have the IFR for the same function. NOTE . . . "Hard Deposits" built-up in those passages, which carb cleaners/soak solutions would NOT remove, which is why I had to remove them mechanically!
So, as I had a Carter carb, I had to remove the hard deposits mechanically with a drill bit of appropriate size. Holleys will need a new primary metering block. Yes, there are provisions to change the IFR dimension, but it takes drilling out the seal plugs, modifying the IFR size, then re-sealing the plugs. More recent Holleys have screw-in "jets" to do the same function, in the primary metering block.
Holley 4bbls also have an idle circuit related to the secondary throttle bores, with an incognito set screw which adjusts how far open the secondary throttle bores are at hot base idle. Many are unaware of these things as they are not seen unless the carb is apart. The reason they are hidden is that they are NOT to be adjusted after the carb is originally assembled on its assy line. That little bit of idle fuel flow through the secondaries is supposed to keep the fuel in the secondary float bowl "more fresh" than not. Even if the vacuum secondaries remain closed all of the time.
Until we get more information from the OP . . .
CBODY67
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