383 dies in gear when under load from lights HELP

[72 charger]

Hey all, I have a 72 charger with a freshly rebuilt 383 that ive have been having issues with for probably the past year. The car runs great when idling in park/neutral and when cruising at highway speeds. When it gets hot and its idling in drive gear it spits and sputters like its going to die. I put an electronic fuel pump on mounted right by the sending unit in the rear of the car i also left the mechanical on so that the electronic keeps the line pressurized. The pump has a regulator in it and is supposed to pump around 7 psi. After installing this it fixed the issue i was having with the car completely stalling when it would sit in drive gear at idle while hot, it still acts like it wants to die at times almost like its "skipping a beat". The car also seems to have more pickup when driving instead of spiting and sputtering when accelerating from a stop. I still have an issue when I pulled the car into the drive yesterday night it actually died when I had it idling in drive gear AND under the load of the lights. When i turned the lights off the car would idle fine in drive gear. It also seems to only do this when it is at temp 195 degree stat in it. I have no idea where to do from here im assuming its not getting enough juice to the ignition when under load from lights but what could cause this? any help would be appreciated im at a loss at this point.

 

[HawkRod]

My first thought is vapor lock, although that is not consistent with the lights issue. But I am wondering if that was just a coincidence.

I would carefully check the routing of your fuel line to verify that it is not too close to a high heat source like the the exhaust. Also, an insulating gasket under the carb might not be a bad idea if you have the under hood clearance.

I'm no expert - just my $0.02

 

[bigblock]

You need a higher amp alternator and update the charge wiring.

 

[72 charger]

If I need a higher amp alternator why is that the car only dies under load of the lights? The amperage is what charges the battery or what?

 

[super-bee_ski]

Hmm,
Not sure,
But if as "bigblock" says, the alternator is NOT providing enough amperage because after all, once the car is "powered-on" does not the alternator ALSO provide (voltage) to the coil and in turn spark to the cylinders?

But hey, my suggestion was a torque convertor so, hang on untill "bigblock" and someone else helps...

(I'm following closeley)

 

[jcskokos]

to me it sounds a lot like a fuel issue. Has the carb been rebuilt or at least tuned recently? check fuel filter? it should only have about 1/2" to 1" of fuel in it while running if mounted up/down, if it appears to be full then it is clogged or empty, it has a pump problem. The filter was the problem on my car, it had been sitting for a while before I bought it, I replaced the filter then within a couple months it was plugged again. Popped a new one on and its feeding good now.

 

[Garys1969RR]

I had the same problem with my 451 engine, Holley 780 carb. The choke mechanism had been removed, and air was leaking into the carb thru the choke pull off orifice. Sealed it, and works fine now. Try opening the idle air screws 1/2 to 1 turns from where they are now. That will richen up the low speed circuit in the carb. If it improves the situation, then you have an air leak somewhere which causes a lean condition. What carb you using?

 

[bandit]

Have you checked the coil with an ohmeter? When they start going, they'll act up once they get hot. After driving a bit and warming up, the heat will start expanding a coil that is starting to fail and it will lose it's strength. Engine will slowly start sputtering and probably stall as it heats up. It's all good when it cools down again. Once this starts though it is not far before the coil is toast and you have no start at all.

Your coil might be just starting to go and maybe when you are driving, the alt pushes enough power to compensate, but when you are idling, it is not enough???

Worth a check. Easy replacement.

 

[72 charger]

I have a holley 600 on the car now. I had the car "professionally" tuned and went through before assuming that there is no issue with the carb and fuel mixture. Vapor lock sould also be out of the picture due to the fact of the electronic fuel pump pressurizing the lines now and i have them wrapped in aluminum heat shielding around engine bay as well. It seems odd to me that it could be a fuel issue when it will only stall when the lights are on. As for checking the coin no i have not done so its relatively new though what would i have to do to check the coil?

 

[krowbar]

How hot is the engine actually when you get it warmed up and it wants to die? Do you have a good temp gauge to read it?

 

[72 charger]

I do not have a temp gauge I have a 195 stat in it though I was suggested to put. 180 in but local parts stores have 195 or 160

 

[krowbar]

I do not have a temp gauge I have a 195 stat in it though I was suggested to put. 180 in but local parts stores have 195 or 160

I was having a problem with overheating. I wrapped the lines with heat tape. Put a heat spacer under carb. New rad. Still ran shitty when it warmed up and the temp gauge only read 160°. I knew it was hotter than that. I replaced the temp gauge and thermostat. Problem solved. The thermostat wasn't opening all the way so the block was getting too hot.

 

[Garys1969RR]

Lets assume its an electrical problem, which it seems to be. Not sure how to check the coil, I think Meep Meep would know how. Looks as if coil voltage is probably dropping when the lights go on. Do you have a good ground strap from engine to ign box? That's important. Also check all the grounds to make sure they are clean and tight. Electrical resistance goes up as the temperature of the conductor goes up. The resistance creates more heat which makes the problem worse. I would try to hook a voltmeter to the positive side of the coil, where you can watch it when you turn the lights on, or are driving it. It is a blue wire on my engine. And it also comes off the low voltage side of the ballast resistor. Have you checked/changed that resistor? They are pretty cheap, and can fail often. Some people carry a spare one. Being a 1972 model, I assume it is elec ign.

- - - Updated - - -

And the more load the engine has on it, the higher the voltage required to fire the plug. Hope this helps you find the problem. Good luck.

 

[bandit]

There should be specs you can look up for what your specific coil should read. Here is a generic way to test it and what it should read: http://wiki.answers.com/Q/How_do_you_test_an_ignition_coil

If you have no way to test it, go and buy another one from autozone and return it if it does not solve your problem. Your issue really sounds like the coil to me

 

[72 charger]

Are you kidding me

Ok so I haven't been on here in a while but in the mean time I've finally figured out what was the issue with the car stalling and generally running like a turd :yuk: out of all the things it could be of course its the simplest thing that you wanna kick yourself in the *** for. And if anyone has followed my posts I've been trying to figure this out for probably over a year. :iamwithstupid: Anyways I took the car over to the gentlemen who tuned my carb and set up my electronic ignition after I installed it and who has been trying to help me figure this out along the way. We sat there and tested the coil battery charging volts amps coming off alternator at idle and then under load of lights all checked out so as I go to leave it started acting up and he turned around and looked clueless as I have been for over a year. He said maybe you should check your plugs. I told him they were brand spanking new and all gaped properly and I had pulled 2 from each side to check em. He said he thought maybe the gap was too close on one and that it wasn't firing right sometimes and under the extra load of the torque converter while in gear and at idle thrown in with the dead weight from the piston it just stops the crank so I said ok went home pulled all the plugs laid them out according to cylinder and here my #6 plug the gap was maybe 5 hundredths. Here I must have smacked the side of block putting the plug in as I checked all the others and they were fine. So being the plugs I originally got were autolites I went and just bought a brand new set of 8 champions checked the gap on each very carefully and Installed VERY carefully and boom the car ran like a dream and I beat the snot out of her. Obviously I was ecstatic but at the same time pissed that all this time It was something so stupid being over looked. :angryfire: Anyways figured Id give an update to my problem finally being solved cheers. :VB toast:

 

[Garys1969RR]

Well glad you finally solved it! I always run Chanpions in a street motor. I have dropped a plug before and it closed the gap up, so now if I drop one I re check the gap. Happy motoring!