skipping on #4

[rhettnowell]

My 99 gt which i have owned since new started leaking at the thermostat housing, which has just been set up at a recall at ford. Several months ago i switched out the intake for one with the aluminum water jacket and thermostat housing. Also i have added the underdrive pulleys new plenum and throttle body. I have got this skip in #4 now that i can't seem to diagnose. New plug, new coil pack, replaced valve springs, compression test is good. I replaced the old pulley/damper on the crankshaft, still no help on the skip. Any suggestions what else to check?:

 

[PowerSplash93]

Make sure that there is no antifreeze on the plug where the wire or coil attaches to, because that could also cause it to skip, best way to try and fix that is to spray some brakekllen or electrical cleaner on it, I changed an intake on a mercury villager and got some antifreeze on one of the plugs and it wouldn't run for *****, sprayed some brakekleen on the plug for the cylinder that was missing and it ran like a dream!! Just something to check.
Matt

 

[bill302]

do what power splash 93 says, you need to make sure you have a spark. if so run a compression test and post results.