Im tracking down the cause of this rough idle , take off and cruise. I removed the fuel filter and notice a lack of back pressure at the tank side connection.
Changed filter and same symptom.

Should I see back pressure ? Fuel pump is last item on list to check off.

171,000 miles on original sending unit.


This all started after I washed my engine off a week ago.

Regards.

 

The only fuel pressure reading that maters is the one on the zerk up on the manifold. at that zerk you should have a minimum of about 40 psi.Got a check engine light? Got the engine wet so your most likely problem is a fried coil..

 

ok, I picked up a new Coil pack for #5. BWD for $55.00 for one. Are the coil sets on Ebay quality? hell u can get a whole set for $80. Should i put dialectical grease on the coil spring at plug contact?

 

avoid the super cheap coils. We like these.. http://www.ebay.com/itm/1998-2008-LINCOLN-TOWN-CAR-IGNITION-COIL-VISTEON-BRAND-NEW-ALL-8-PCS-/370944224459?pt=Motors_Car_Truck_Parts_Accessories&hash=item565dffaccb&vxp=mtr

 

Do NOT put grease on the spring or contact - just inside the boot.

 

You washed the motor then have trouble?
Never do that with water and hard spray.
You just got water into the plug wells.
There is no way for the water to get back out.
When the motor heats, it turns to steam vapor so nothing improves.
Take all coils and boots out.
Blow the plug wells clear, clean and dry.
The coils are likely good so inspect the boots closely for signs of pinholes and cracks. Replace those that look questionable.
Use the dielectric grease on the boot tips flat end and just inside so the boot "finds" the plug when you reinstall the coil assembly.
All you have is to 'feel' when the boot sets down on the plug since you can't see what's happening.
Leave everything else alone.
Good luck.

 

Running smooth , Changed out the plug and pack on #5 & #6 Plus a New Fuel Filter for good measure. Thanks for all the help.