A friend once brought me his mid eighties ford bronco ll with a starting/slow crank issue. So, I start eliminating causes, checking this and that, battery/starter draw/cables/ends/charging rate. After several run cycles,
the thing finally refuses to crank. Hmmmm....Acts like the engine locked up
Verify by attempting to manually turn engine over with front crank pulley.
Yup, stuck....Gotta verify one more thing tho, check for hydro lock. Anti freeze full, hmmm. I'll take the 3 drivers side plugs out and have a look.....OOps,almost forgot to disconnect that mile long coil wire from the distributor cap.....I'll just ground it to this a/c bracket, it'll stay......This pos is
equipped with the boat anchor 2.9 v6, which had the reputation, at that time, unbeknownst to me, of fuel pressure regulators rupturing internally
and silently filling the engine with raw fuel.........OK, ready to crank. turn key
only to see coil wire jump away from ground point, create spark, spark ignites fountain of gasoline spewed from three removed plug holes, and
creates a gigantic orange mushroom cloud roaring out from under the hood.
Probly took around 35 secs to get to the fire extinguisher (I was outside luckily) although it seemed like several panicked minutes. Extinguished the last bit of flame JUST as the entirety of the vehicle wiring harness was beginning to melt. After nearly having to change my shorts, we decided to push it in, rack it up. Seemed like it drained for 5 minutes after removing the oil drain plug. I learned to always remove power from the ignition coil
itself, NOT grounding the coil wire, FOREVER thereafter.