So, my car has developed a new problem just today.
It's a 67 Dart, 170 /6.

When I left to go to work, I stepped on the gas, not soft but not really hard, and it stalled. Started her back up and went a little easier on the gas. Didn't stall, but sputtered and hesitated and made what I can only really describe as a popping noise. When I hit the gas harder, like to merge into traffic, it would sputter and almost stall until I let off the gas. Once I could get her going, she would coast just fine, but the second I get on the gas pedal, it does the sputtering/stuttering thing.
It seems like a fuel delivery issue, but it doesn't do it in neutral and the idle is fairly smooth. It's been pretty cold here of late (15-20 degrees), so I don't know if that is having an effect. I haven't made any changes or adjustments recently that might trigger it. It seems to get a *little* better when the car is fully warmed up, but it still persists. I thought maybe it was a choke issue. Choke was fully open when I checked it after making it to work.

I left work about 6 hours later and tried it and it's still doing it. Being that it's freezing and dark out, I only did a very brief check. I did notice some oil on the valve cover around the oil filler/breather. Could the PCV system be clogged? The PCV valve itself is rattling, so it doesn't appear to be gummed up. I can't really do much tomorrow, cause I work a 12 hour day. Anyone have any lightbulbs going off of things to check right off the bat? Looks like I'm taking the bus to work tomorrow!

 

Check your distributor cap and take a look at the condition and gap on your points. I've also had condensers go bad to where it would idle but, a little throttle would make it stutter and run funny.

 

i'll give it a look....just redid the rotor, points and cap in August though....it was running fine up until today....

 

hey man im in the same boat. i can let mine fully warm up, give it a little gas to start to accelerate, and its not until i give it enought throttle that the accelerator pump kicks in and then the car moves as it should.

i can drive it, then shut it off for a few minuts, and it will be perfectly fine. Its not until it became below 35 degrees here that ive had this problem, so that is telling me that the carb is not that far out of tune

sounds to me like its not until the carb builds a little heat that it actually run good. is this possible? ive been over ignition and fuel and air filters and cant figure out a solution. Silverick, i have a new coil condenser, if thats what your refering to, ill put it on tomorow.

anyone have any ideas???

 

Salty -

Real long shot here, but could you have developed a vacuum leak? Not that familiar with those carbs, but could also dirt on the needle/seat.

Archer

 

Hmmm, not sure. I could check that. The vacuum from the carb to PCV valve was very strong when I pulled the hose off.
I was wondering if it could be tranny-related? Since the engine runs fine until I put it in gear.

 

Salty,

Ok, I'm back onto the points situation again.....

1) The points could have moved if the screw wasn't tight but, don't over do it.

2) The little plastic thing on the set of points that rides on the distributor lobe, if not lubed, will wear and when it wears, will change the gap on the points.

3) Have you checked the pressure on your fuel pump?
That would cause what you are describing and now that I think of it, I may be on to something here. Maybe the fuel pump diaphragm didn't like the cold, and failed.

I may be off base and, I'll be honest here, I am a native Californian and have never had to deal with cold weather and an old car.

Frank,

I am talking about the condenser that is inside of the distributor cap and connects to the points.

Does your car have electronic ignition?

 

It has an electric pump installed by a PO. I was thinking of replacing it with a mechanical one. I think that'll be my next step. I'll check the points again too. Not ruling anything out at this point.

 

Yes it does. im going to run a vacuum test on it today to check for any leaks and im also going to check all other vacuum hoses. can thier be any thing within the electronic ignition causing this? after the car sits for a few and i crank it back up, it is fine till it cools off again while driving.
thanks a bunch, Frank

 

It is possible that this is a fuel delivery problem, or water contamination in the fuel. Could it be a filter plugged/ icing up?

Has the engine been modified? You have the factory manifold or headers? You have an aftermarket carb/ intake / carb spacer?

(You may not be getting enough carb heat)

I didn't catch what model year? Does it have carb "snorkel heat?"

I agree, though, that condenser/ coil/ ignition COULD be a cause.

You said you redid the ignition in August--but a condenser can fail ANYTIME or be bad right out of the box. "New" does not equal "good."

How hot does cranking spark look out of the coil wire?

What exactly does it do "hood up?" Can you "goose" the engine with it seeming normal, or does it puke out the carb with sudden engine accelleration?

Is it a rythmic pop? This could indicate a stuck valve type problem or a flat--even exhaust lobe--on the cam

Weak coil/ weak condenser can be a very subjective problem, because they can deteriorate the spark JUST enough to cause these kinds of troubles

Another trouble with ALL these old girls is the bulkhead connector. Does the charging system seem normal? I ask because the same conductor through the bulkhead connector is the one which supplies both ignition and the voltage regulator. If this connection is poor, you may be getting very low ignition voltage

You can check it: Engine running, stick a probe of your meter RIGHT on the battery POSITIVE post, the other probe on the ign side of the ballast resistor.

You are looking for a VERY low reading, the LOWER the better, and zero would be perfect. If this reading is much above .2 (that's two tenths) of a volt, it indicates too much voltage drop.

Your basic voltage path is from the coil resistor (ign) through the bulkhead, to the connector on the ign switch, through the switch contacts, back through the ign switch connector, to wherever under the dash the harness splice is, to the ammeter, back through the bulkhead, to the main feed, and to the battery positive.

 

Hey, thanks for all the tips. Hopefully this weekend, I'll actually have time to check all these things. So, a little bit of a development, despite it being a balmy 35 degrees, it was doing the same thing last night. This AM, it was about 15 degrees, so I woke to a frost-covered car. Started her up and let her warm up for a full 10+ minutes as I scraped the windows off. Got in and pulled away. Had some slight hesitation, but within a half mile, it wasn't doing it anymore. Cruised at 30-45 mph most of the way to work. So maybe it's a choke issue? Like it's going from open a carck to fully open when warm, with no middle ground? Tomorrow I'm gonna start her up without the air cleaner and see what happens with the choke. This issue didn't start at all til we started getting into the teens (and lower) for temps. And it's my first winter owning the car, so anything is possible, not knowing how she reacts to extreme temps.

I do have a question though, since you brought up the bulkhead, I have noticed that when I'm driving, my blower motor speeds up and my headlights get brighter when I'm giving it gas. As I come to a stop, the lights dim and the blower slows down.

 

PS, as far as i know, it's a stock slant 6, 170, 1 barrel carb, no snorkel heat (you mean pre-heater hose?), factory intake and exhaust manifolds, no modifications I know of, other than the electric fuel pump form the PO. Which makes me wonder why he went that route instead of just replacing the mechanical one.

 

LIghts / blower: A certain amount of lights up/ down is almost unavoidable in winter driving, the question is how much it too much? I'm not sure at what point Chrysler improved the low RPM performance of alternator designs, some people say ALL of them do this to some degree.

Snorkel heat: Yup, my word for the preheater hose. Especially on the newer cars, as smog regulations got tighter, this is important

Frankly, after your last description, almost sounds to me like you got some water/ ice in the fuel stream and that it finally worked it's way out.

I'd be tempted to test the pump. You need a common vacuum/ pressure gauge, which everybody should have, anyway. They are about 15-25 bucks at any parts store, and you can probably find one used if you look around.

I'd eyeball the pump and see if you can ID it just by sight. There are only "so many" common replacement pump models that look as they do. You'll need two checks:

Disconnect the line near the carb and eliminate the filter (check that by blowing through it while you are at it, or just replace it) and connect your gauge, and check the pressure.

Then take a can/ bottle that you have an idea of the capacity, and time the pump into the bottle.

If you've ID'd the pump you should be able to call around to some parts stores and find out the ratings, the pressure rating and the "gallons per minute."

Here:

http://www.airtexproducts.com/TSB/TSB-0108-01_ATX.pdf

for example is some of the claimed specs on Airtex replacement pumps. The top first chart is all you need to look for.

 

This comes with owning a '60's era Mopar!!

My '68 Fury does the same thing as did my other '68 Fury!

I just installed a new alternator and It doesn't seem that it did this, as bad, with the old one and my AMP gauge does wierd things now.
I'll figure it out, maybe with a little help, and let you know my findings. Rick

 

sounds like the accelator pump is out in the carb.Your engine is lean poping, when u open the secondaries, thats why it doesn'nt do it at all or as bad when your easy in it because its just running on the primary curcuit. hope this helps

 

Hmmm, interesting. It's weird, today it's in the 30's, a lot warmer than it's been and it hasn't been doing it since this AM. If it is the accelerator pump, wouldn't that be a constant condition? Because it does go away when the engine is fully warmerd up, which is leading me back to choke again....i'll have to check it in the AM when I'm not at work.

 

Well if you think about what a acc. Pump is mabe of when it's colder the diaphram will be brittle and if it has a small pin hole or tear it's more likely to allow the pump to opperate incorrectly. When it warms it will be more plyablebtyere for sealing off any small imperfection in the pump. Hope this help. I would ck the choke just to be certain that it's open. You would no if it was stuck, it would be running extremely fat and idleing rough

 

And I forgot to answer you on it being continuious problem, and the answer would be no, because the acc. Pump is only used under hard acceleration or basicly when the secondaries are opened. That's why this makes me think it could be your issue. Good idle and poor acceleration!