Post by
95-J30tt »
https://forums.nicoclub.com/95-j30tt-u40286.html
Sat Mar 07, 2009 11:48 am
i think the best thing to start with is to read the ECU codes, run the onboard diagnostics, and see what comes up (more than half of the fault codes will not cause the Check Engine Light to turn on)
then take it from there. change the air filter if it needs replacement. did you relocate or modify the air intake, as in, have you installed a cone filter or such ?
check your vacuum lines, turn engine on in a relatively quite area, open hood, listen for any strange air sound (hissing sound) coming from the engine bay, and locate the sound if it exists, most of the time it would be coming from the small black hoses running on either side of the engine (vacuum lines).
ohm your injectors with a multi meter (with the engine off and cold), make sure to set the multimeter to resistance, the readings should not be above 14 ohms for each injector "otherwise, the injector is toast"
clean the IACV (Idle Air Control Valve), it's in the back of the plenum, on the driver side, unplug the connectors and (if i remember correctly, 2 air hoses), and remove 4X10mm bolts holding it to the plenum. clean it and install it back
there are two electrical connectors in the front of the engine (they are on the aluminum coolant hoses leaving the engine in the front centre). basically, they constantly monitor the temperature of the coolant, and send the data to the ECU (if the connectors are dirty, they could be the cause of the idle issue).... take them out and clean the connectors, and plug them back in.
do you feel like your transmission is slipping/not shifting properly??..........check transmission fluid, do that by driving the J for a good 10-15 minutes, then park the car, (make sure that the engine is fully warmed up by then), check transmission fluid level, and make sure that the fluid doesnt have any black particles in it (the transmission could be the issue causing the idle problem, if it is about to go....)
clean the butterfly valves.... with the engine off and cold.... remove the intake hoses where they meet the plenum (2 big clamps), pull the intake hoses out of the way,you will expose the butterfly valves (you will see one on either side), get someone you trust to press the gas fully and not let go while you are working (key should NOT be in the ignition)... spray the butterfly valves with some brake parts cleaner and wipe with a clean cloth that doesnt leave particles behind.
i'm sure there are more simple things that i have missed, but try this out, and update, i hope that this will at least narrow it down.... best of luck