Hello Slant 6 Forum! I resently purchased a 71 Dart Swinger that has a /6 in it. I was able to drive it home but it had a pretty bad vacuum leak at the number one intake runner where it bolts to the head. I went ahead a replaced the intake/exhaust gasket in hopes of fixing the exhaust leak. Problem was the car wouldn't start after the new gasket. Thinking maybe the points condenser went bad, since I wasn't getting any spark and while looking into the points noticing the wires where date coded 4-70 I figured a tune up was in order.

I changed cap, rotor, points, condenser, wires, plugs and after noticing the coil was only giving a orangeish spark I changed the coil as well. I also know the ballast resistors can go bad on these so I changed that too. After changing all of that I was able to get the motor to fire up but sounded like it was missing a cylinder. So I triple checked my points and plug gap and set the timing at TDC (just to get a baseline) and now I can't get the motor to start at all.

The coil is putting out a blue spark now, I know at least the #2 cylinder is sparking (only on I pulled to see if I had spark) and if I put my finger in the carb and pump the gas my finger gets gas on it. I'm at a loss as to what could be the problem.

Any help would be greatly appreciated.

Does it cough or otherwise try to start, or just crank and crank? Do you have it at TDC compression, and not exhaust? (Make sure the rockers on #1 are loose when its at TDC, you can usually reach them with fingers through the oil fill hole). Watch the firing / plug wire order.

Were the points set on the high side of the dist lobe or on the flat sides? I would presume the points are not adjusted correct or you may have the firing order wrong on the dist... I ask because I did the same thing on a vehicle after not setting points for a long time. Got it to fire, but couldnt get it to accelerate at all, even in neutral the engine would just back fire and die.

Also, knowing that it ran before the gaskets, maybe the carb is way out of adjustment due to someone over-compinsating for the vacuum leaks. Double check the float, and try to find a starting point on idle speed and mixture as well.

_________________
"if it aint broke, fix it till it is"
78 Plymouth Volare Super Six wagon
89 Volkswagen Golf GTI 16v
92 Chevrolet K1500 5.7
98 Ford Escort ZX2 zetech

Right now It will crank fine and then want to thump/cough rather than fire off. When I turn the key off theres a little plume of smoke out of the carb. Which would lead me to think the timing is off. I got to my assumption of TDC by having someone in the car smack/tap the starter with my finger in the #1 cylinder, when it pushed my finger out that should be TDC.

This is my first time working with points and I was told to set them at the top (high side) of the lobe and between my shop manual and this site I set them at .020 gap. I've checked my wires/fire order using the old distributer as well as a diagram that I found on this site and they all match what I have run on the car right now.

The previous "mechanic" did raise the hot idle to basically where the cold idle was to compensate for the vacuum leak. I lowed the base idle back down so it didn't bang into gear and noticed the stubble and die off idle more. Which led me to just fix the problem the rather than cover it up.

Sounds like the points are set right, also does sound like its gonna be carb related and partially timing related. If it is at TDC to around 10* BTDC should get it to fire.

Thats still once the carb is checked out. If its old and grungy, been tampered with alot, mis adjusted float and idle mixture screws will cause an immediate over-rich or over-lean condition and wont allow it to start without playing with the throttle at the same time.

Another area to look at just to be sure theyre right is the valve adjustment. They SHOULD be set hot, but you can adjust them cold to get it started and re-check or re-adjust once its warms up.

Your kind of in that greay area when everything needs to be gone through and rechecked once one thing gets fixed... Kind of like a domino effect.

_________________
"if it aint broke, fix it till it is"
78 Plymouth Volare Super Six wagon
89 Volkswagen Golf GTI 16v
92 Chevrolet K1500 5.7
98 Ford Escort ZX2 zetech

From what I can tell I'm not the first person to take the intake and exhaust manifolds off either. The exhaust manifold has typical grease pen marks from junkyard and I'm missing some of the triangle washers on the bottom of the manifolds. Not likely causing the problems I'm having right now but still just more stores this motor/car is telling me.

Just so I'm understanding your statement on timing correctly I should be good if at TDC or 10 degrees advance?

So where is the best place to buy a rebuild kit for the 1920 Holly? I've been buying most of my stuff from Rockauto for this and it does look like they have a rebuild kit. I've just been worried about adding more variable to the fire and rebuilding the carb would add the "did I screw up the carb" variable to the party. This would be the first time for me rebuilding a carb, I've heard its pretty strait forward but that was from guys that have done a lot of carb rebuilds. And at some point I plan on dropping one of the 440s I have around the house into the Dart so I've been try to avoid making the /6 into a money pit.

Move the timing back to where it ran.
Again, it sounds like the timing is off.

When you replaced the intake gasket, did you draw it up evenly? A vacuum leak at the head can be a real "no starter" Ask me how I know!

Hang in there you will get this all worked out.

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Timing has been the biggest question mark with this engine for me. I took the distributer out to replace the points and condenser and when I took it out i noticed that the distributer was turn all the way to the left (counter clockwise), or a least as far as the top hold down point would let it go. When I put everything back together I put it there first and couldn't get it to start so I put In the middle of the hold down bolt and it would start but had the miss I described earlier.

I tried to follow the inside to outside as best I could but the middle bolts under the intake center section where a PITA as I'm sure you are aware of. When it did run with the miss it did have a vacuum leak under the carb so I bought a new gasket and that cleared that leak up. I was at this point that I pulled the distributer again to double check my point gab and plug gap and it hasn't started since.

The weird part was I think I actually miss set the points to wide the first time and some of the plug where gapped too small....and it at least started then.

One more thing that may matter is this car was sitting for about 2 years in the guys garage before I bought it drove it home. It had about 1/2 tank when I left his house an about 1/4 when I got it to my local gas station. I filled it up with super and put a bottle of Lucas fuel treatment in it at that time. I'm still on that tank of 3/4 super and 1/4 old stuff right now and I'm around 1/3 of a tank. Other than wanting to die/dying off idle the car seemed to run fine on the drive home and the little bit of around time driving I did with it before changing the gasket.

Start with making adjustments on the carb first before just tearing it apart. It ran before, just not correctly, so with minor adjustments you should be able to get it to run again.

The traingle washers are VERY important when it comes to torquing and sealing the manifolds correctly. Without them the manifolds wont torque down evenly and increases the stress on the mounting point of the manifolds.

For the timing yes, in most cases tdc-10* range should be enough to get it to run. Factory timing for it is probably in the 2*-6* range, but you cant accuratly set that until its running and running smooth. Start at TDC, then crank, see how it does. Then add just a tiny little movement of advance and try again. Along with firing order being right, did you make sure that the rotor points to the wire leading to #1 cyl and theyre not maybe one or two towers off?

On the carb: Set the idle speed screw to about 1-1.5 turns after contact, then turn the mixture screw(s) all the way in and then back each one out 1.5-2 turns. This will be a good base to start at, but will require readjusting once it is running right and fully warmed. Take a look at all the choke pieces too, is anything sticking open or closed? Idle speed cam moving and not the choke plate or vise-versa?

Theres probably more info out there as others chime in, but thats about the majority of the stuff I can think of without seeing or hearing the car itself...

_________________
"if it aint broke, fix it till it is"
78 Plymouth Volare Super Six wagon
89 Volkswagen Golf GTI 16v
92 Chevrolet K1500 5.7
98 Ford Escort ZX2 zetech

I did put all the washer back where they came from when I took the manifolds off the car but like I said there was some triangles missing. The last person just used some regular washers in place of the triangle washers.

Yes when I double check my timing I took the cap off to make sure the rotor was under the #1 cylinder tower.

I would definitely try and get the triangle washers in place. A regular washer probably isn't holding back much and you may still have a leak even after you get it running.

Rick

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

So I was able to get the car to start but it sure doesn't want to. I bumped the timing up some but thats the only change since my last post. If I just pump it a couple of times and try to crank it will crank fine then rather than start it does the thump thump thump I talked about earlier and have some smoke (almost like a little back fire) though the carb when I turn the key off. What I did to get it to start was pump it while cranking it and it got over the thumps and turned over. It was able to idle but it was really rough and sounded like it had a missing cylinder. If I gave it a little gas it seemed like it wanted to die but if I gave it a good amount (more than half peddle) it would rev up. Once I get the RPMs up it had good throttle response. Once it makes it back down to idle it would idle really rough again and sound like a missing cylinder.

I'm planning on going out tomorrow and start working on the idle mixture screw per oldskoolracer's baselines earlier in this thread. Just from looking at the idle screw earlier it looked like it was really far out put I will look at it tomorrow and let you guys know then.

Just want to say thank you all for the help so far. This was something my dad and I where going to work on together but he past away while I was deployed over Christmas so working though this by myself with help from you guys.

I'm going to look around on ebay tonight to see if I can find some. I think I only need 3 or 4. Funny part is I found one while I taking the manifolds off that wasn't even used by the last guy. It was stuck in the grime on the side of the block.

So I just adjusted the mixture screw all the way in and back out 1.5 turns (it was about about 3.5 turns) and it started and ran about the same. It does smell like raw fuel when it dies at idle which I would think would mean its took rich. I guess the next step would be to take the intake and exhaust manifolds back off and put some blue permitex on the gasket to try and make sure its sealed. I was planning on doing both sides but what would you guys suggest.

If you really wanna pull the manifolds again, get the correct hardware first so you can re-install it correctly and rest assured it torqued faily evenly... I dont generally recommend using any sealer on intake or exhaust gaskets, if you do I would recommend a copper-coat. If things are clean, flat, and torqued right you wont have a leak. If you are in doubt, you can cash out on remflex gaskets and never worry again (until you find a reason to pull it apart again)...

Sounds like it is flooding out and thats why itll start with all the extra throttle. You should make sure the float is set right and look close to the needle and seat to make sure its not damaged or swollen. A piece of debris will keep it open as well and just keep filling the carb with fuel.

Im not personally familiar with the 1920 Holley but there is ALOT of info on this site. Rebuilds are generally really easy to do. Take your time, take photos, have a clean clutter free work space and youll be good to go. Disassemble, clean, blow out passages with air, match gaskets and reassemble. Youll have to do all the base setting again (float, idle speed, and mixture screws)...

_________________
"if it aint broke, fix it till it is"
78 Plymouth Volare Super Six wagon
89 Volkswagen Golf GTI 16v
92 Chevrolet K1500 5.7
98 Ford Escort ZX2 zetech