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Help 68 charger 383 auto dies when put into gear

Wicked31

Wicked31

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I’m out of ideas so I’m turning to the knowledge of this forum for help.
68 charger 383 auto idling at 850 drops to 500-600 rpms eventually dies if no throttle is added. Installed a 750 street demon since old carter was leaking from everywhere. Checked for vacuum leaksby spray contact cleaner around intake/carb disconnected all vacuum lines and plugged ports doesn’t seem to have any leaks. Adjusted carb with vacuum gauge best I could get was 12-15. Timing set at 12*. Switched to a Holley dp I had laying around same issue. Not sure if there’s an electrical issue that could be causing it, wore out camshaft, transmission/ torque converter issues? Any help would be appreciated. Thanks
 
I know this sounds weird but it happened to me, check coil. Mine would idle but once I put it in gear it shut off. Turned out the coil was bad. It’s a easy and cheap item to check. Good luck.
 
Are you using a choke? Is it fully open when it's at normal operating temp?
 
I rebuilt my entire engine one time because I couldn’t figure out what was wrong. Got everything back together and the same problem existed. It was my distributor cap the whole time. Had a fracture crack in it. Cost me a complete rebuild, who would have thought.
 
Charles Cook said:
I rebuilt my entire engine one time because I couldn’t figure out what was wrong. Got everything back together and the same problem existed. It was my distributor cap the whole time. Had a fracture crack in it. Cost me a complete rebuild, who would have thought.
Click to expand...
That’s why I’m on here. Lol it’s crossed my mind a few times to yank that motor and throw the 440 in that’s sitting in the corner.
 
This happened to me for a few different reasons.
1. carburator rebuild didn't use ethanol proof kit.
2. carburetor adjustment - curb idle set too low for cam
3. bad alternator, would stall at low revs/shift into gear/ turn on headlights
 
Have someone put it in gear & let it die while you watch the timing marks..... Just something I've seen a few times, if your idle speed is high enough to bring in some mechanical advance but when you drop the car in gear it drops the RPMs and that advance starts to fallout... You loose a degree or two & the RPMs drop further so you loose another degree... at some point all the timing falls out & with the car in gear the engine can't idle with so little timing/air & so much (minimal) load...

The cure? Slightly heavier springs in the distributor to hold base timing till around 1000 RPMs...
 
Looks like your torque converter is putting quite some load on the engine once in gear, in that case the engine will need some more air and fueling to keep running.
You could try and set the idle timing and fueling while in Neutral, not in Park, with the hand brake on.
Difference is that when in neutral the transmission oil pump is providing oil pressure to the whole system, which adds load on the engine, in park there is only circulation.
(If you would raise the rear wheels of the floor and let it idle in neutral, you probably find your tires start to spin/creep slightly)

Do you have any specs on your camshaft and torque converter? (aftermarket/stock?)

You can try and give it some more initial advance 14-16*, add 1/4 - 1/2 turn on your idle mixture screws to give it a bit more fuel.
And if you are using one, make sure the PCV valve is working and the engine is sucking air through it at idle.
You can also adjust the idle screw a little and open the primary throttle a bit to provide more air, though the rpm will go up because of that.
if the rpm raises too much you can lower it by removing some initial advance.
 
I had the same issues, and thought the Demon was to blame. Turned out to be the distributor. I replaced the Chrysler electronic setup with a Mallory breakerless magnetic and it solved the problem.
 
I'm guessing not enough spark advance as well. It will act like it's too lean.
You can check the quality of the spark pretty easily by pulling the coil wire and placing it about a 1/4" away from a good ground point (bolt head).
The spark should be blue/white not yellow and you can hear it crack.
 
Most of us have chased carb problems that turned out to be ignition.
With your carb switch and it still is acting the same...
I think these guys are right.
For a simple test on a warm engine pull the vac hose off the distributor and plug it then start it. Grab the timing light and dial in 18 or 20 advance at idle. Reset your idle if it's to high.
Then put it in gear.
 
Think your running too low of rpms for the automatic trans. Need to up idle rpm's to at least 1000 rpm's. So when load is is added by putting the trans. in gear it will continue to run and not stall. Carb adjustment may be out also. Electrical part's may be an issue also like other's have said. A good coil like MSD will take car of a lot of problem's. Went through two Elder brock coil's and they were junk. Put an MSD one on and no more problem's. So you say it run's good at idle dose it reave up well also. Then when putting in gear it wants to stumble and die. Increase you rpm idle and see what it dose then. Good luck.
 
blue69runner said:
Think your running too low of rpms for the automatic trans. Need to up idle rpm's to at least 1000 rpm's. So when load is is added by putting the trans.
Click to expand...

Problem with this is that the trans will slam into gear quite hard, 750-850 should be possible with a street car.
Actually lowering the rpm to something like 650 will reduce the transmission load as well, but your engine needs to be capable to support that with the camshaft and the right converter.
Any long duration cam c/w a low stall converter will not really like to run that low.
 
The mopar .455 cam in my 383 would idle at 625 in gear no problem.
The .484 cam in my other 383 idles pretty low as well maybe 700 or so.
 
Thanks for the replies. I don’t know the specs of cam or converter but I’m sure they are fairly stock as the rest of the car is very stock. I’ll throw a new coil in today and possibly a distributor if the coil doesn’t help. I set the timing in neutral at 12* I had it at 15* originally and backed it back down.
 
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