Tune Up Help!

[PortlandJohn]

I have a '99 w/ the 4.0 SOHC w/ 173K. Good engine, but it needs a tune up. She's pulling some low MPG's, around 15 combined.
I have cleaned the throttle body mulitiple times, and cleaned the MAF as well. Near as I can tell, the plugs are original (I got her when she 9,000 miles) as well as the wires and coil pack.
Other than changing out the plugs (and possibly wires and coil pack), are there any other ideas I need to look into to get the MPG's up? I appreciate the lowering gas prices and all, but I also want her to run to capacity.

Thanks in advance,

Portland John

 

[PortlandJohn]

I seem to have hydrolocked my 99 SOHC after I cleaned the throttle body. I am assuming that I used too much this time as I have cleaned it many times w/out incident. Any ideas on how to proceed with a hydrolocked engine?

 

[swshawaii]

If hydrolocked, hopefully you didn't cause internal engine damage. Remove ALL the plugs and crank the engine to
expel any excess Seafoam. Reinstall or replace with new OEM Motorcraft or Autolite plugs and pray for the best. GL