I have a 1992 Ford taurus and it runs rough at idle. It was tuned up 6 weeks ago, new plugs, wires, etc. It also chugs when going up an incline at 35mph & 1300rpm. If I give it more gas its ok. Any ideas?
Did the problems exist before the “tune up”? Did you do a compression test? any reason to suspect a mechanical problem with the engine?
Are you confident the new parts installation went good (plug gaps are OK, plug wires not damaged, didn’t break off any vacuum fittings)?
Does the EGR system check out(poor valve seating would give you your rough idle)
Any possibility of plug wires cross-firing (get a spray bottle of water and mist the distributor cap,wires,and spark plug end of the wires,do it at night,see if you get a little lighting show).
After all ignition and mechanical potential sources of your poor running,start looking at the fuel system.
You can spray potential vacuum leak areas with carb cleaner,if the idle rises and smooths out momentairly you have found your vacuum leak.