Spannerhead's '99 XLT Log and Thread o' Questions (with pics)
02-21-2015, 06:32 PM
#31
Impractical
Thread Starter
So it's been really cold here the past few days.
Thursday on the way to work the truck started shuddering once the temp needle started to move off the stop. Felt like a dead cylinder. No CEL until later in the day when it threw a P0304 (misfire cylinder #4).
Between the pinging I had last fall (bandaided by running 93), my first thought was that a fuel injector died, since I reasoned a bad coil would throw the appropriate code.
Replaced all 8 fuel injectors, spark plugs and fuel filter earlier today.
It's still shuddering. This is the condition I found the boot for #4 cylinder in:
The plug was wet with coolant too. All the others were fine.
Bad intake manifold gasket?
Thursday on the way to work the truck started shuddering once the temp needle started to move off the stop. Felt like a dead cylinder. No CEL until later in the day when it threw a P0304 (misfire cylinder #4).
Between the pinging I had last fall (bandaided by running 93), my first thought was that a fuel injector died, since I reasoned a bad coil would throw the appropriate code.
Replaced all 8 fuel injectors, spark plugs and fuel filter earlier today.
It's still shuddering. This is the condition I found the boot for #4 cylinder in:
The plug was wet with coolant too. All the others were fine.
Bad intake manifold gasket?
02-22-2015, 08:45 PM
#32
Impractical
Thread Starter
Any ideas? I replaced the intake manifold gaskets and the EGR valve today. No change.
Really frustrated right now. I got a P0306 (misfire on cylinder #6).
Bad coils would throw a specific code, right?
Really frustrated right now. I got a P0306 (misfire on cylinder #6).
Bad coils would throw a specific code, right?
02-22-2015, 09:08 PM
#33
Impractical
Thread Starter
Awright, after some research it appears that bad coil(s) may throw a code, but only for a second. I'd have thought my OBD2 scanner would have picked up the stored code, but it didn't...
Anyway, my next parts to replace are the coils. Any yeas or nays?
Anyway, my next parts to replace are the coils. Any yeas or nays?
02-23-2015, 08:12 AM
#35
Senior Member
Change the plug wires, use Motorcraft. A leaking heater hose can drip into the no.4 cylinder.
02-23-2015, 01:51 PM
#36
Senior Member
Motorcraft
02-28-2015, 06:15 PM
#37
Impractical
Thread Starter
Replaced the coils on Thursday; no difference.
Next item on my list were the plug wires. I bought a set from O'Reilly, and before I put them on, just for kicks I misted a little TB cleaner around the base of the intake manifold, checking for vacuum leaks. No difference.
Then I reseated all the injector clips, and lo and behold, the truck runs perfectly again. Much better than before, actually, given all the junk I've replaced.
Mystery solved. 
Next item on my list were the plug wires. I bought a set from O'Reilly, and before I put them on, just for kicks I misted a little TB cleaner around the base of the intake manifold, checking for vacuum leaks. No difference.
Then I reseated all the injector clips, and lo and behold, the truck runs perfectly again. Much better than before, actually, given all the junk I've replaced.
Mystery solved.
