1966 Charger. Rough idle, won't stay on.

[vuduchikin]

361/727. Points ignition. Relatively new distributor, about 8~ months old. Plugs same age. Brand new Accel plug wires. New coil (reads good ohms). New voltage regulator (ran another ground wire from bottom bolt to block). Ground wire from block to firewall. Going to run a second ground from battery to core, just in case. Good battery. Good alternator (except it has no spacers, unsure if this can affect ground heavily?). New wiring harness. Brand new thick heat gasket for carburetor. Edelbrock 1411. The mixture is super touchy. Anything past 2 1/2 turns out will almost always kill the engine. Timing set currently to 12 BTDC (will get to that later). New timing chain, no audible slap.

Vacuum gauge from carburetor reads 17~ inch. Rapidly shakes 1-2 inches. Read that this likely indicates some sort of ignition issue.

Was having issues getting it to idle properly. Backfire with black smoke at higher RPMs. Seemed like vacuum advance was causing issues. Disabled that, looked to run a bit smoother for a while. Now it's having the same issues. Will start up fine and idle for a little while. Then will die randomly. After that, it will crank and hiccup unless I keep the pedal to the floor, then it will start very very rough. Adjusting timing hasn't helped whatsoever (if anything, it runs a bit better when more advanced than 12 BTDC at idle).

Kind of at my wits end on getting it to run properly. I don't like using mechanics for issues like this, but I need fresh eyes. Does anybody have any ideas?

 

[Bighouse]

Check your firing order. Make sure all cylinders are firing

 

[jmbass98]

Firing order good. Could plugs be one off in rotation? I figured that would make an obvious miss sound, not just rough idle.

 

[Don Frelier]

Firing order is the first item check several times.
Pull the plugs, line them up and compare color are they wet? Black?
Take some heavy rubber gloves and pull one plug wire at a time and see what changes.
If you have headers from a cold start run about 15-20 seconds. Shut it off and see which tubes are hot/cold if any.
Next check the float level and fuel pressure (it should not be more than 5-6 psi) it certainly sounds like it's too rich.

 

[slimt]

Do you have a vacuum line loose. ?

 

[Jerry Hall]

Do you have a vacuum line loose. ?

Or vacuum leak at the base of the carburetor or around the intake.

 

[LowBikeMike]

Having to hold the pedal to the floor on restart would point me to an extremely rich mixture/flooding issue. You mention the carb adjustment is very touchy, can you explain that situation more?

 

[slimt]

Or vacuum leak at the base of the carburetor or around the intake.

Yep. Had that happen as well.

 

[Hemi 354]

Got to start with the BASICS for sure. Firing order (18436572), Vacuum leaks, timing, any fouled plugs?

 

[QOTHL]

361/727. Points ignition. Relatively new distributor, about 8~ months old. Plugs same age. Brand new Accel plug wires. New coil (reads good ohms). New voltage regulator (ran another ground wire from bottom bolt to block). Ground wire from block to firewall. Going to run a second ground from battery to core, just in case. Good battery. Good alternator (except it has no spacers, unsure if this can affect ground heavily?). New wiring harness. Brand new thick heat gasket for carburetor. Edelbrock 1411. The mixture is super touchy. Anything past 2 1/2 turns out will almost always kill the engine. Timing set currently to 12 BTDC (will get to that later). New timing chain, no audible slap.

Vacuum gauge from carburetor reads 17~ inch. Rapidly shakes 1-2 inches. Read that this likely indicates some sort of ignition issue.

Was having issues getting it to idle properly. Backfire with black smoke at higher RPMs. Seemed like vacuum advance was causing issues. Disabled that, looked to run a bit smoother for a while. Now it's having the same issues. Will start up fine and idle for a little while. Then will die randomly. After that, it will crank and hiccup unless I keep the pedal to the floor, then it will start very very rough. Adjusting timing hasn't helped whatsoever (if anything, it runs a bit better when more advanced than 12 BTDC at idle).

Kind of at my wits end on getting it to run properly. I don't like using mechanics for issues like this, but I need fresh eyes. Does anybody have any ideas?

Did you have the carburetor built, by whom and how long ago?

 

[vuduchikin]

I will check for vacuum leaks again. Carburetor should be intake - gasket - adapter plate - carburetor, right?

It is a shelf-bought carburetor. Had it for around a year and a half.

I'll pull plugs, confirm firing order, etc. as well. Will report back.

 

[Bighouse]

Intake - gasket - adapter plate - GASKET - carb.

you should post up a few pics

 

[vuduchikin]

Allright... Added a new gasket.

Somehow this is getting worse as the days go on. Added about 2 gallons of fuel to the car today. At least a few days ago, I was able to drive the car around the block with only some backfire from exhaust before the car would die in the driveway as I was working on it. Now I can't get it to idle for more than fifteen seconds before dying.

I really don't understand what else to try at this point. I am unsure how it keeps getting worse with me doing nothing but slightly adjusting timing and mixture. Even trying how things were set before isn't making it run that same way.

Just picked this coil up. Reads good ohms. Had an MSD Blaster 2 in that only read .9~ ohms, apparently I shouldn't run those with the stock points system. So I got this one.

Testing was all done with car jumped.

Ballast reads 12v - 6v as it should. Coil reads 2.6-3v rapid fluctuation on neg, 6-7.5v fluctuation on pos.

 

[slimt]

Does the automatic choke stay closed after starting? Hold the choke open with a pen or something that wont fall inside then try it .

 

[slimt]

I notice the vaccuum advanced on the distributor is blocked? Is there a reason for that?

 

[vuduchikin]

Was setting timing with vac advance disabled.

Did some reading on this "Ballast reads 12v - 6v as it should. Coil reads 2.6-3v rapid fluctuation on neg, 6-7.5v fluctuation on pos."... and it def seems like those are low voltage readings on the coil, lol. I feel like I have enough grounds. They are solid connections. What could be causing voltage drop from the ballast to the coil?

 

[vuduchikin]

Where exactly on core support do people run a ground from battery to? Does anyone have a picture example?

 

[slimt]

Was setting timing with vac advance disabled.

Did some reading on this "Ballast reads 12v - 6v as it should. Coil reads 2.6-3v rapid fluctuation on neg, 6-7.5v fluctuation on pos."... and it def seems like those are low voltage readings on the coil, lol. I feel like I have enough grounds. They are solid connections. What could be causing voltage drop from the ballast to the coil?

Voltage regulator A new chinese chip plate one or the old point style american?

 

[slimt]

Where exactly on core support do people run a ground from battery to? Does anyone have a picture example?

Usually the front of the block .

 

[Purepony]

Intake manifold gasket vacuum leaks ?
The last time I had a similar problem like yours where it would star a d then die it was the intake gasket leaking. A friend advised me to spray brake cleaner carefully not to light anything up and the car would stay on when I sprayed it on the intake.
Turned out it was the intake gasket all along