Poor Mileage

[240fan]

93 ka24I had disconnected the crankcase breather a year ago and just put a filter on it, but its been idling very low and rough when in in drive. like 400RPMfirst did fuel injector cleaner, 4 bottles nothing changedsunday I reconnected the breather to the intake and it idled much better but the mileage has become atrocious* do I need to disconnect the battery to reset the ECM ,maybe?* do these have vacume or mechanical timing advance?*is marvel mystery oil in your gas good for cleaning injectors?*is it time to check the timing? (143,300 miles!)

thanks !

[Aries]

check the timing.Next check plugs and wires. (they can cause the rough idle)You can try resetting the ECU, but it's not likely to change anything.There is an idle adjustment screw, but I'm not sure where onthe KA24e

[TrunkMonkey]

There is an idle adjustment screw, but I'm not sure where onthe KA24e

stand on the passenger side of the engine bay and look toward the back of the intake manifold.

-demetrius

[bruinbear714]

What condition are your plugs in? Is your car running a little rich?

If it's running rich then you might want to check your MAF sensor, or fuel injectors can be leaky. Also check the vacuum line that goes to the gas tank.

[drjohn]

Check the basics,timing, plugs,etc. but don't forget to check the coolant temp sensor and the o2 sensor. By putting a filter in the oil breather line you are adding unmetered air to the engine and the o2 sensor tries to compensate.This unmetered air could mask other problems such as a coolant temp sensor connection or a sensor out of range. With that much mileage if you haven't replaced the o2 sensor in say the last 40 to 60 k its probably do. Also if the carbon canister or evap system is still on the vehicle with that kind of mileage there have been a few cases where the canister goes bad and raw fuel is drawn through the purge line directly into the int. manifold.

[240fan]

Thanks for all the info, the plugs are 3 months old. there is no unmetered air, the pcv hose is the same as original equip.Ill check all the other stuff out !