1973 Dart Swinger with a small plug engine (is this right for 73?), elect ign

The car has a misfire (engine shudder/puff out exhaust) at idle that worsens when under load but tends to disappear while cruising. The car also idles wayyyy down in gear.

New parts: car/rotor, coil, ballast, coil wiring, plugs, plug wires, vacuum lines (straight to dist), battery, fuel filter

Since I've replaced every thing except the ECU and Dist I tested the dist per the 74 chassis manual I have. The manual stated that the dist pickup coil should show 350-550ohms. Mine showed 220ohm at the ECU and at the dist. Is this faulty or just possibly a timing issue(no timing light or tach).

I plan to check voltages around the ballast, alt, coil tomorrow but it seems decent since it will idle forever in park..even with the miss.

Fuel problems also appeared after the new filter was put on. As stated car idles lowww in gear and likes to die when you try to get moving from a start. If by chance you do get moving it will also try to die when giving gas out of a slow corner. Going to try without gas cap tomorrow because that would so the same thing as the vent line to carbon canister, right?

Hot or cold I have both issues.

Also adjusting the valves tomorrow.



Help me get her going guys..Thanks

First, the small peanut plugs didn't come along till about 77/78 depending on the model. Sounds like someone may have put a peanut plug head on your 73 block. It isn't bad mind you, I am running one. I use NGK UR4 plugs #6330. They are the best for the SL6.

Do you have a 1920 Holley or the 1945? It will help to know for trouble shooting. The carb manuals are listed with stickies at the top of this page. See if you can identify what you have by looking at the manuals.

It sounds like a carb adjustment or rebuild is in order next. The float may not be adjusted right, the bolts holding the carb down could be loose causing a vacuum leak. The carb bowl could be full of debris. These are just basic things to check for.

Do the valve adjustment hot while it is running. Grab a 3/8 box end and some angled feeler gauges .010 for the intake and .020 for exhaust. Who knows if a valve is hanging open a little the adjustment may smooth it out.

Let us know what carb you have. You can also click on the red link below my name and see if the your carb looks like mine, a 1920 Holley.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Sounds like you are well on your way with troubleshooting.

First things that come to my mind are;
How do all the new plugs look?
Are you sure the ignition wires are hooked up correct?
Is the choke adjusted right and the choke stove assembly smooth and the shaft bent well so that it doesn't hang up through full travel?

Don't underestimate how much trouble that choke could give you if its not adjusted right. Ask me how I know or better yet check out my other recent posts regarding choke. I was where you are right now not long ago. I wish I could tell you exactly what the cause is, I only know that if you keep at it you will get it running well.

Good luck!

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74 Dodge Charger 225 factory A/C auto 1920 carb stock exhaust.

Mods;
HEI, MSD B3, Magnecor 8 mm, ZFR5N, .060 rotor, CH410X cap, new 3874814 dist, fuel mod, valves hot .010 & .020, all new hoses, JP chain, brake hoses and fluid.

Oh yeah... My car would idle great but hardly make it up the street. The whole package is at work but I noticed the most improvement on my car going to the HEI module with new coil, plugs, wires, dizzy, cap, rotor etc. I think that the HEI mod/ignition upgrade has been my best money spent so far.

Before I had all the pieces together, I installed the new NGK plugs (I have a different head than you) with the old dizzy, old wires, old coil, new cap and new rotor and did notice it ran a touch better but nothing like how it runs clean and strong with all the ignition goods now finished.

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74 Dodge Charger 225 factory A/C auto 1920 carb stock exhaust.

Mods;
HEI, MSD B3, Magnecor 8 mm, ZFR5N, .060 rotor, CH410X cap, new 3874814 dist, fuel mod, valves hot .010 & .020, all new hoses, JP chain, brake hoses and fluid.

Its a 1920 carb and I picked up a Walker kit and a rubber valve cover gasket this morning so rebuilding it and adjusting the valves are on todays list (both a first for me).

Did find yesterday that the block side carb nut could be moved with my fingers so theres one vac leak.


Any ideas about the dist. pick up coil reading? Is lower than the FSM range bad? I'm making a run to a somewhat local Mopar yard today and my grab a distributor just incase, or at least test some of them to see what they read.

Thanks

Peanut plugs have been around a long time (you will find that all the other makes of the Big 3 used them long before Mopar did...yes, it's fun to park a mopar outside and ask for a set of NGK's for a Boss 351 from your local auto parts store)...The shift to the BL plug head happened in the 1975 model year.

-D.Idiot

Alt output : 13.5-14.5V
Ballast: 3 prongs: 12.5-13.5V
Ballast: 4th prong: 5V
Across top 2 ballast prongs: 0.9ohm
Across bottom 2 ballast prongs: 3.5ohm
No other real readings across ballast prongs
+Coil: 5V
-Coil: 2.5V
Across Coil: .9ohm

Consulting my chassis manual then rebuilding the 1920. Tell me what you see with my readings

I think vatozone gave me a ballast with too much resistance, thus killing voltage to the coil+. Tried swapping the wires around and still at 5V, did try all combos or try bypassing it yet.

I would:
1. test for vacum leaks.
2. Adjust the valves.
3.Adjust your carb per the FSM or the manuals on the top of this forum.
4. Rebuild the carb if neccessary.
Frank

_________________
Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

MISFIRE FIXED!~

thinking back it appeared after i did the cap/rotor/BALLAST

just bypassed the ballast, 9V at coil+ and purring like a kitten. Still idles way down in gear but i'm sure the carb rebuild and a new gasket will help.

What kind of resistance should i see on a new ballast, so I can test it before i buy it....stock replacement napa coil.

I would go for 1 ohm or less. In the pictures of my setup you can see the MSD resistor which is .85 ohms. It provides 10 volts at the coil at 600 rpm idle. I had the 4 wire set up like yours (mine is a 74) and rewired it for a standard two wire setup.

The earlier 5 volt reading you had is what I use to see with the stock 4 wire resistor.

Glad your making progress!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

carb rebuild was successful and made it around the block without the low speed die out. going to cruise some more tomorrow to make sure building some heat doesnt kill it

not only was the carb loose, the gasket was upside down and backwards

If the heat does kill it, go to a 180 stat, that will help, but the fuel line mod and the heat deflector help allot too. Whether you use aluminum or some other material, keeping the carb cooler will help on the 90+ degree days.

Hot restarts are quick, with out the constant cranking till it fires. Usually just hitting the key and it's running.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG