I have a 225 on a 1970 dart that has a miss or sputter. It doesn't sound like a constant missfire . All of the cylinders are firing and just installed a hotter coil. New plugs, wires, and cap did not fix it. I pulled motor last year to install cam and shave head. Also installed bigger valves. It was doing the same thing before I rebuilt it. I only did work on the head. The bottom end was rebuilt by previous owner. It still has the holley one barrel with new carb kit. It does it through out the rpm range. Can't find a vacuum leak anywhere. Would a warn carb cause this? Has anyone ever had this problem? Would appreciate any advise. Thanks Joe

What are you doing when it sputters? Applying throttle? Letting off the gas? Just cruising at a constant speed? If it happens when you are applying throttle, it could be the accelerator pump inside the carb is bad and is not squirting the right amount of fuel. Could also be that one of the breather passages inside the carb is blocked. Maybe the float isn't set correctly and the fuel is not filling up the bowl enough?

I recently rebuilt my carb and they sent me the wrong internal accel pump gasket and I didn't realize it until after much frustration and taking apart and putting back together.

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63 Dart GT Convertible

Have you adjusted the valves lately?

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Casually looking for a Clifford hyperpak intake for cheap.

When I first got my slant it was having a mis-fire/sputter issue under all conditions, and it was driving me crazy. The engine compartment was a mess, wires everywhere, disorganized, many previous "experiments" went on in there apparently. Finally, I traced a random (hard to see thin and black) wire on the fire wall that was running under one of my heater hoses and was pinched in one of the spark plug tubes (shorting)...yanked it out, sputter fixed! Maybe you have an electrical short somewhere, cracked/exposed plug wire?

bg

Couldn't find any shorts or bad wiring. Valves have been adjusted. New plugs and wiring. I plan on installing a four barrel intake and carb soon. Maybe the problem will disappear with a new carb. Thanks

Myself, I would find and correct the problem before throwing something else into the mix!

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1964 Dart GT

Just at my wits ends I guess. Even some of your best mechanics replace parts till the problem is solved. Who knows, maybe the intake manifold has a small crack. Already sprayed some starting fluid near any possible location that a vacuum leak can occur. But I'll keep trouble shooting wiring. It seems like it's always an easy fix. Thanks.

You might try pulling the carb and putting a kit in it, might have a partial blockage in a passage.

Richard

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Part of Tyrde-Browne Racing

I installed a kit. Measured float hieght. Cleaned passages, made sure jet was cleared. Made no difference. The engine sounds great except for that sputter. When I am revving the engine and leaving it at that rpm (2000-3000 plus), It sputters. It is really hard to described. That's why I am leaning towards a new carb. But I plan to check wiring out one more time inch by inch. Probably check timing again. Thanks

I suspect an electrical problem if it isn't an intermittent sticking valve where the miss or skip manifests at 2000 to 3000 rpm.


Do you have points or electronic ignition?

If points:

Replace points and condenser, be sure to lube the distributor center shaft cam lobes that open the points. Bad condenser can cause skip.

If EI:

Make sure orange box, voltage regulator, and alternator are grounded well. All three devices have to be at the same potential as negative battery terminal, in other words no voltage drop between any one of the said devices and negative battery terminal. This can be accomplished by installing a #10 gage ground loop that picks up VR, Orange box, and alternator that attaches to each of the devices body, or mounting plates.


One more thing; clean and remake all battery connections, and ground connections to block, and head to fire wall ground strap. Once you are confident that there is no ground problems via testing with volt ohm meter, take the time the time to inspect all wire and connections in charging circuit, replace as necessary.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Okay, I'll try that and see if it helps. Thanks

While the engine is running, check the voltage at the battery. Then check the voltage at the alternator output. Check, the voltage on the high side of the ballast resister. They should all be within .5 volts of each other, and should be somewhere between 12.4 and 13.5 volts . If not, there is high resistance in the wiring harness somewhere. The bulkhead connectors, and amp meter are famous for having high resistance as they age. Things will get better with new wire and connectors. If the voltage is low, your alternator, voltage regulator, or wiring and connectors in between are suspect. This is a simple check which will reveal a great deal about the car.

Sam

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