I have a 74 Swinger that's all-original with 49K miles on it now. Had it from 35K.

The car has an odd issue: On cold startups, I pump the gas once, it sets the choke, starts great, and I pump the pedal once to get it off-choke.

Warm starting is different. The engine pretty consistently cranks for quite awhile before it catches. When it does catch, there's no stuttering, or pseudo-catching; it catches and that's it. But it sometimes takes 4-5 seconds on warm starting where it's cranking full tilt for it to catch.

I'm not a mechanic, and I have a guy who knows my car pretty well and has worked on it since I've had it. He's looked at the carburetor while it's doing what I describe. He's played around with it and says it's not a carburetion problem, he thinks it's a module (electronic ignition, or some other kind of module), that's causing the hard starting. He told me after checking out the car while the problem is happening, that the car is not flooded, and the carburetor mixture is not wrong.

Can you guys give some advice on this?

I think it's both (carburetion and electrical). Today's California gasoline is markedly different to what was available in '74, and you can get some really obnoxious hot-start issues with the present formulations. Make sure your heat riser valve is working correctly. Do the fuel line mod. Make sure you've got the correct thick bakelite carb-to-manifold spacer, and install the carb heat shield.

The original '73-'74 ignition modules were notorious for causing this kind of issue, so you may want to buy a quality replacement module (Standard-BlueStreak or Echlin) and install it.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I agree with SlantSixDan. I had almost the same problems starting it hot until I did that Fuel Line Mod and upgraded my Coil. I also put platinum plugs in. Now I have absolutly no hot/cold starting issues. That mod does wonders for hot starting.

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

Thanks Dan and dusterguy. I'll give these mods a try and see what the result is.

Platinum plugs are generally not money well spent on a slant-6 engine. Instead, take advantage of the fact that you have a pre-1975 engine and use the NGK #ZFR5N extended-nose spark plugs. Remember to remove the metal ring washer from each plug before installing it. Tune-up parts and technique suggestions in this thread. The stock coil, as long as it's in good condition, will work fine with the stock type ignition system — but if the coil is failing, it can cause hot start/hot running problem. I'd focus on the fuel system heat mods and the ignition module first.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Well, it was platinums or just the regular and the platinums were on sale, so they were the same price.

I didn't know you had to remove the metal washers! Maybe I should go do that.

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

In addition to what has already been stated, heat soak and carb/fuel line boiling and vapor locking is a problem in cars with a cramped engine bays and low hoods especially in warmer weather. In trucks it doesn't seem to be quite as bad. Van's are worse than cars. With the intake bolted to the exhaust it a fact of physics. The factory at one point started installing heat deflectors, a hard insulating blanket to minimize the effect. Carb gaskets have gotten better, thicker over the years to also help minimize the effect.

I have changed ECU's, installed a MSD coil, and the MSD resistor, rewired the engine harness, gone with the NGK plugs, Blue Streak cap, MO-3000 long tip rotor, 8mm spiral core wires, made my own aluminum heat deflector under the carb, installed longer studs so I can use the better carb gaskets and have done Dan's fuel line mod with fuel injection hose. On a hot day, 95 plus degrees or more after driving a long distance and shutting the car off to shop for 15 to 30 minutes, it will start as fast as I can release the key. It takes about a half a turn on the stock starter. With the new electronics I see 10 volts at the coil at and idle, before it was less than 5 volts.

So there are a several fixes that may help.

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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

The only things electronicaly I did was replace the coil, bypassed the ballast, new plugs, and voltage regulator. The fuel line mod I "moded" a little to my liking, and used the fuel injection line, and that got rid of all my starting problems. Heck, I think the thing even runs better. The only heat problem I have to overcome now is the snorkle on my air cleaner broke off, but that will soon will be fixed with the super six.

Good luck to ya Eatkinson. Hope your car runs better!

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

dusterguy225,

When you said you bypassed the ballast, does that mean you did the GM HEI mod? or are you still running the stock Mopar ECU?

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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

I am still running the stock Mopar ECU. The reason I had to bypass it was because I put a pertronix flamethrower coil in. That post is here.

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

I see you got the 3 ohm Pertronix coil.
Have you noticed any difference in the plug color?
Are the plugs burning hotter?
What brand plug are you running?

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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

I have not pulled the plugs since I changed the coil. When I changed the coil, I replaced the plugs with Bosch Platinums. I have to take them out soon, as I have learned your not supposed to leave the metal washer on them. I will probably do that tommorow.

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

I have never had good luck with Bosch's spark plugs. Especially the Platinums, where they burn out within the porcelain and by looking you'd never know. (No inner electrode stick-out to judge condition) The "super's" are exactly what youre paying for; a cheap plug that won't last as long as even the beleagured as of late, Champions Ive been using for years. I'm between plug changes right now, but as I've heard so much about the NGKs I may give them a whirl the next time.

Bosch spark plugs are junk. The platinum ones cause more driveability problems than they solve, the +2 and +4 items are a scam, and the ordinary "Super" ones are a low-quality plug which if I'm not mistaken is, like Autolites, now made in China.

Use NGKs.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

What are NGKs? I have never seen that term before.

I had Champion plugs before, but the didn't seem to perform that well, but I could be mistaken.

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels