Reply to "cold start problem"

...Choke My A**!!!

If You Have Spark and You Have Fuel...That Engine should be Fireing Over!! That leaves something 'Mechanical', such as Poor Compression or Bad Timing.

Your plugs are Black, that would indicate to Me, Weak Spark! Perhaps Wrong Plugs or Wrong Gap; Or Both.

You have Fuel, Have You been squirting gas down the Venturies until You Flooded the Carb?

You say, You DO Have spark? Did You check it AT The PLUG? This will indicate Problems in the Rotor and Distributer CAP! What about the Plug Wires?

How Old is the Battery?? Over 4 Years and it may Not Take a Charge or, Most Important; HOLD a Charge and then Deliver Full Amperage ON-DEMAND!
Next Check the Battery Voltage at the + COIL, WHILE Cranking! If it Drops Below 8.8 Volts while Cranking, that's a Problem!
A new Battery may be Your Fix. If You Do go shopping for a Battery, I DO NOT Recommend a 'DRY-Cell'!! Go for the 'Heaviest' Lead-Acid Battery You can afford! The Largest Battery that will Fit, With CCA of, at Least, 800 or More!!

Could Be You have a 'Weak' Coil, Temperature Related! Hardest to find is the 'Intermittent' Fault. Check the Coil for Internal Grounding/Shorts and for Ohms Resistance. Would Not be the First Time, the 'Electronic Modual' has Failed!

When You check for Spark at the Plug, the Spark should be More than just a Arc! It should show up as a 'Blue Flame'!!

Last...STOP Cranking until the Battery is Dead!!
You'll just burn-out the Starter Motor! The Starter gets Hot, The Resistance Goes Up-Exponentially, the Starter DRAWS More Current...Less Current to the Coil! Weak Spark, At Best!!

If the Engine Does Not Fire Right Up! It is Trying to Tell You Something!!
Stop Screwing with the Choke!!! When Cold, the Choke Plate should be OPEN a Gap of 1/8 Inch!! NO More, NO Less!
When warmed the Plate should be Fully Straight-Up!

Now Get To Work!!

And don't let those Monkeys get anywhere near Your Pantera!! NO Belt Buckles, Zippers, or Levies with Copper Rivets!!!...