1966 Dart troubleshooting

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C

Colorado

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Fort Collins, CO
Hello from N. Colorado! 66 Dart 270 Slant Six, 3sp a/t. Car was running great then I noticed on the way to work that when I'm hitting the gas, it moves but it "putters" along with a jerky hesitation in acceleration. Almost like it's not getting any fuel. The only time I feel the car running normal is when I have a wide open throttle. Here are some more specifics:
-Car does not idle nice anymore, when I come to a stop for stop sign or red light is usually stalls right when I've almost completely stopped the car. Also stalls when I get up to crusin' speed sometime when I let off the gas for more than 10 seconds
-Used to be able to put in drive with no gas, let my foot off brake and I would just cruise/idle at abt 5-10mph forever. Now when I put it in drive and dont hit gas it goes for maybe 10 yards before car shakes and stalls out (unless I jam foot on gas)
-There have been instances when in drive and I hit gas and engine almost stalls but then all of a sudden jumps forward. Car will accelerate forward, but has trouble doing so in consistent manner even with a heavy foot.
-Car is fine in Park, N, R... But in D, 1, or 2 it does the stalling.
-No problem starting car, runs through 3 gears fine as long as I'm giving it gas.

Could this be fuel pump? Carb? Idle needs adjusting? I can answer any questions about the specificity of problem.

I apologize, this maybe a really easy question to answer but I'm new to working on cars, specifically cars not fuel injected, so any help would be greatly appreciated. Thanks! :)
 
First thing I would look at is the accelerator pump on the carb. With the car NOT running look down in the carb and then open the throttle and see if you get an instant shot of gas in there. I DO mean instant, as in right now.
 
Might be vacuum related. Check the carb is tight to its base gasket, etc..
 
Bad Sport said:
First thing I would look at is the accelerator pump on the carb. With the car NOT running look down in the carb and then open the throttle and see if you get an instant shot of gas in there. I DO mean instant, as in right now.
Click to expand...

Okay, did exactly what you said. I had an issue with starting the car about 3 months ago and I swear when I was looking into carb that there was more "play" to it than this. Also, no fuel anywhere that I could see. I have attached a picture and a short video to elaborate. Perhaps I am missing something very basic or am doing it wrong. :banghead:

Video: [ame]http://youtu.be/7WXawR65A4o[/ame]
 
The choke being open when the car is warmed up is normal. It should however reset to closed on a cold engine after throttle is depressed once.

Sounds like you may have a blockage in the idle circuit. While some symptoms suggest accelerator pump, it is often possible to accelerate slowly and get past that, and idle would be normal.

One simple fix is to try to clear the idle circuit at idle mixture screw. From the present setting lightly screw it in while counting exact turns. Then screw it all the way out, clean it with a shop towel and carb cleaner. Then use the red tube on carb cleaner to squirt cleaner in the carb where the mixture screw was removed. Carefully replace screw, lightly seat it and back it off the number of turns you counted.

If that does not fix the problem, it is time to put a kit in the carb. If the carb is a holley 1920, the metering block has internal passages that may be difficult to clean.
 
Did you try to wiggle the carb ? They can come loose or even come apart.
Vibration, throttle pulling on it, all contributing factors.

Sometimes getting it warmed up good and holding the throttle open to high rpms you can push the butterfly closed briefly causing vacuum to suck trash from the jets.
 
Sounds just like my 69 Dart slant w/ Holley 1920. Ran like that for decades until I finally got a new carb that worked (others didn't). One guy says there is a way to blow out blockage if you remove the carb and know which bottom hole to blow thru. Another problem could be that your fuel line on the suction side is collapsing. If soft, due to ethanol, replace them w/ better "fuel injection" hose. That bit me on a long trip until I found it. However, different symptoms, the engine would start sputtering above 55 mph or going uphill, but idled fine (or as well as it did with the bad carbs).
 
KitCarlson said:
One simple fix is to try to clear the idle circuit at idle mixture screw. From the present setting lightly screw it in while counting exact turns. Then screw it all the way out, clean it with a shop towel and carb cleaner. Then use the red tube on carb cleaner to squirt cleaner in the carb where the mixture screw was removed. Carefully replace screw, lightly seat it and back it off the number of turns you counted.
Click to expand...

Dumb question, and the car may not even start without screw, but do I need to use the carb spray while engine is running? Also, do I just spray it in there and let it be? Sorry for the newb questions, this car is my first car in my life that I've been able to tinker with! :D
 
No need to run it with screw out.
It is sometimes possible to back the screw out a turn with running engine to let the dirt pass, then back in.

My first car was a 66 Coronet with /6. I drove it 8 years. I sold it to buy the Barracuda I still have after 35 years.
 
UPDATED: I sprayed the carb spray in as suggested then waited overnight to try and run it and see how its doing. Well, woke up and the damn thing wont start. I don't know if I sprayed too much or what so I went this morning and sprayed some starting spray and it still wont start.... Any ideas of what I'm doing wrong or how I just made this problem worse?
 
A couple 2 second squirts is plenty. Most carb cleaners are combustible. My advice is stay away from starting fluid.
The cleaning method is a short term, maybe work, band aid.

You may have other problems.

Things to consider:
Have you made any other changes?
Have you checked the plugs? I recently helped someone get a car started. The plugs were like new, but fouled with a shiny black carbon that prevented sparking. He had miss connected wires at the coil by placing choke heater on point connection. He then used a bunch of starting fluid. Not sure if they fouled from that, but never saw plugs like that in my 40 years of working on cars.
Do you have spark? Look for blue spark at plug, with plug body grounded.
Is there fuel in the carb? This is often checked by seeing if squirter sprays fuel.
Does the engine have compression?
I have heard that starting fluid will spin an engine without fuel or ignition, because it fires on compression. It can also break rings off pistons. Learned this from experienced machine shop mechanic.

A short 2 second squirt of WD40 in the carb with choke open, will run an engine about 2 seconds without fuel, if the ignition is working.
 
KitCarlson said:
A couple 2 second squirts is plenty. Most carb cleaners are combustible. My advice is stay away from starting fluid.
The cleaning method is a short term, maybe work, band aid.

You may have other problems.

Things to consider:
Have you made any other changes?
Have you checked the plugs? I recently helped someone get a car started. The plugs were like new, but fouled with a shiny black carbon that prevented sparking. He had miss connected wires at the coil by placing choke heater on point connection. He then used a bunch of starting fluid. Not sure if they fouled from that, but never saw plugs like that in my 40 years of working on cars.
Do you have spark? Look for blue spark at plug, with plug body grounded.
Is there fuel in the carb? This is often checked by seeing if squirter sprays fuel.
Does the engine have compression?
I have heard that starting fluid will spin an engine without fuel or ignition, because it fires on compression. It can also break rings off pistons. Learned this from experienced machine shop mechanic.

A short 2 second squirt of WD40 in the carb with choke open, will run an engine about 2 seconds without fuel, if the ignition is working.
Click to expand...

Nice. Thank you for the schooling. I have not made any other changes. Just went to Advance Auto and the guy told me I probably put the idle mixture screw back in wrong. So I tinkered with that, still wont start and so I'm back here........

I haven't checked the spark yet, I suppose that is where my next move is. Thank you.
 
The idle mixture screw two turns out is fairly typical to get you started.
Sorry you are having problems, but it is a good opportunity to learn more about your car. In general they are reliable cars. Carb and ignition work are the most common needs. Once you learn those, it will be easier next time.

Somtimes older cars test new owners, then they settle down and will be good friends.

There are free pdf files for factory service manual online. They provide excellent details on all the service work.
They also have trouble shooting guides.

Once you experience and work with problems they become easier to identify and make repairs in a proactive way.
 
**Update:

Car was left sitting for 5 days and it started right up and now starts fine. Don't know what that's about. Idle screw is now 2 turns out as suggested. Still having same problem. Car starts right up and idles fine in P and R but in D it'll seem like it's fine but once you're off and driving once you need to slow down to a complete stop it stalls out somewhere from 5mph to stop. Once this happens and you re-start the car and put it in D you need to hit the gas quickly or it will usually stall out right then and there. Also stalls out when rolling into a parking lot at a low speed if foot isn't on the gas. I'm often left "coasting" with it stalled out. This is in addition to sporadic acceleration when laying on the gas. Embarrassing.

I have a Valiant service manual for 1966 so it's relevant. So eager to fix this not because I want the car running, but simply because this is such a new challenge to me. If you have any more suggestions please let me know! Thank you!
 
Do you still have points in the distributer? If yes, I would start by checking/replacing them (or converting to electronic ign), set the gap/dwell properly. Make sure the timing is set correctly. After that, adjust the valves, to .010 intake and .020 exhaust, engine hot. After those things are correct, then work on the carb,
PS: Make sure the PCV system is working properly befor adjusting the carb. It does have an effect on the idle adjustment.
 
1----So far as your video. When the throttle is "down" on the curb (warm) idle, most fast idle cams have a STEP which will not allow you to close the choke with your finger. You must "imitate" the choke thermostat, that is, apply a little "closing" pressure the same way that the choke spring does, then open the throttle with the other hand

2---It's not clear to me what if anything you have done for a tune --up. At this point I'd do a major tune of the engine. If this is an original older engine with adjustable valves, do so.

3--Run a compression / leak down test. Inspect / change the plugs. If the cap/ rotor/ wires are a little dirty, and mileage is unknown, change them.

4--Change the points and condenser if there is ANY question, and set the timing at least "as advanced" as the book + about 3-4 degrees.

5--THEN attack the carb. As old as these girls are, there is no reason to assume that any part of the fuel system is in good shape. Replace the fuel line rubber hoses if unknown. One at the tank, one at the pump, and any others up to the carb. TEMPORARILY run a plastic filter so you can inspect for dirt in the fuel, then change to a METAL filter.

Pull the carb apart, clean it, use aerosol carb cleaner to pressurize all carb passages and make sure they are clear. Put a kit in, if the carb float is foam, be aware that these can sink over time. ("fuel logged")

6--AFTER you have set the points (dwell) and then timing, and AFTER you have adjusted the valves, warm it up and set the carb idle. Don't worry about "how many turns" the idle screw is. Adjust the mixture to "what the engine likes." Adjust WHEN WARM. Go back / forth between idle and mixture, set mixture for max vacuum or max RPM, then "just a touch" toward "lean" (clockwise) direction. Engine MUST be warm.
 
Man, what a great amount of information to work with thank you so much. So, I'm going to start checking things one by one, starting with distributor cap. Contacts obv don't look brand new, but I'm not sure if they are worn enough to warrant my attention. I uploaded these, could ya'll tell me what you think about them while I get working on the other stuff mentioned in this thread?

Here are the pics:
http://i.imgur.com/wq2clvK.jpg
http://i.imgur.com/I9QziLN.jpg
http://i.imgur.com/S8S78c5.jpg
 
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