Re: 2000 taurus cylinder 5 missfire
Well if the spark plug is good (clean, correct gap, no black carbon tracking on the porcelin insulator) the plug wire is good, the coil pack isn't cracked, then the only things left are a fuel injector or cylinder leakage past a valve. This will not show up doing a compression check, you have to leakdown test the cylinder. Any more than 15% leakage with the cylinder TDC of the compression stroke indicates excessive leakage. Listen for leakage from the tailpipe, intake, through the oil filler opening. To check for an injector swap injectors between cylinders (you may be able to carefully lift the front half of the rail without removing the upper intake to swap injectors 5 and 6). then see if the misfire has moved to cylinder that the suspect injector has been moved to.
Master ASE Certified L1 Chrysler Technician- still a Ford fan at heart.
1964 Thunderbird Hardtop- Chantily Beige- 390 FE 4V V8-Uncle's Car
1966 Thunderbird Convertible- Red- 390 FE 4V V8- Uncle's other car- waiting for paint and body work!!!