[sector95]

700 bucks and 194K..... If this were my Jeep I would replace everything related to iginiton, fuel and emissions; I would assume (bad word, I know) that all the major components are original and, at 194K, are well past their expected lifespans or on death's doorstep.

Fuel system: replace the fuel pump; replace the fuel filter; (since the XJ is D.I.D.) remove and clean the injectors (otherwise drive it to a good shop and have an upper intake track cleaning done). I would do this one at a time so the injectors go back from where they were pulled. Correct fuel pressure needs to be confirmed at the fuel rail (that feeds all the injectors. Remove the throttle body and scour it clean with intake track cleaner (this is not carb cleaner....it's much stronger and designed to remove carbon deposits). If there is an IAC (idle air control) remove it, clean the passage and install a new IAC..... you want all this stuff to sparkle. Reinstall TB with a new gasket.

Ignition: plugs, wires, cap and rotor.

Emissions: Got an EGR valve? Replace it. Thoroughly clean the crankcase vent system to include the hoses (or replace them). Catalytic converters get plugged over time.... put a new one in.

Compression check: Normally done at operating tempurature but you can get some idea with a cold engine.... Remove all the plugs, pull and ground the high tension lead from the coil. Install the compression tester (it usually screws into the spark plug hole); hold fully open the throttle plate. A remote starter switch makes the job a wee bit easier but barring that, crank the engine with the key. How much? Five or six pops on the cylinder being tested (you'll hear the difference when the tested cylinder runs through TDC).... just make sure you are consistent in the number of cycles. Lowest reading shouldn't any less than 75% of the highest reading..... not sure what the cranking PSI spec is.... this will give you an idea how "tired" the engine is. You can have fairly equal readings between each cylinder but they may all be equally low.... which means your motor is aging properly.


Good luck....

mike