Lexus Troubleshooting Questions? Ask a Lexus Expert
Hello, so sorry for the delay, are you still needing assistance?
ok, good deal so far, so do you have a stethoscope to listen to the injector? or check the injector plug or listen to the injector with a screwdriver to see if it is working?
you are doing no different then i would do, so far so good.
well if you listen with your ear to the end of the screwdriver and the other end touching the injector you will hear the tap.tap.tap of the injector, and compare to other injectors.
ok , so when was the last time the car was filled with fuel? and where were the new parts purchased from?
your issue is above the ignition.
why moving the coil causes change is odd but having that kind of shift of misfires tells me it is something else that is affecting all cylinders and for some reason only a few are showing up. how did this all start?
how are you going to mow the yard with a lexus?......... ah i get it, lol, kidding. ok so yes its something like mass, maf, tps, o2 sensor, fuel, something like that.
firing order fyi
does it misfire at idle or when driving.?
and yes no worries, we are mechanics not English teachers :)
ok if runs smoother then spray around for air leaks while watching fuel trims if you scanner reads live data. spray the intake with brake cleaner or carb cleaner or a little water. if rpms change there is a leak.
ok, so there are only 2 wires on the coil plugs?
ok i see there are only 2, so one wire gets battery voltage all the time, the crank sensor and cam sensor tell the ecm when to fire the coils .
they may flash too fast for the test light or meter to catch it.
since there are only 2 wires the coils fire both cylinder at the same time. the coil and the wire attached to the coil. did you spray any thing around the engine to see if the rpms change?
is there a mass air flow sensor on this model?
i am also checking on some other info.
tap on the egr valve see if it changes the idle, it can be hanging open causing a internal vacuum leak.
also hook up a vacuum gauge to a vacuum line that has constant vacuum ,this engine appears to have adjustable valves. depending on the mileage the valves may need adjusting.
also i forgot to ask what kind of spark plugs were installed. ?
also you did not specify how the issues all started, did the misfires appear after recent work or did the misfires appear before the work?
this engine will run best with NGK plugs. also make sure all the ground wires are bolted on the intake and that there are no stragglers hanging around.
i have to leave for the night i will be back on early am tomorrow, ,let me know if you find anything, we can get this fixed up, well figure it out.
ok so i need to know if your scan tool reads live data or just freeze frame, either way we need to check the map sensor voltage, and the coolant temp sensor readings. does it seem to run better or worse when the engine is cold? as much info as you can give me will help. it is definitely a sensor that is not reading correctly or something that is affecting the whole engine, sometimes so many misfires occur that the ecm cannot determine what cylinder is misfiring. also the fact that you swap a coil and the misfires change is still a clue something is off right there for sure.
ok, see the LT FTRM1 compared to LT FTRM2, that is how much fuel the system is adding to compensate, the difference is huge, they should always be within a percent or 2 of each other not 11%. so keep watching that value and see how high it goes that is a good indication of a air leak internal or external, i am still checking to see if there is another value i am missing.
also you want the FUEL SYS 1 and 2 to show CLOSED, that means that the o2 sensors will take over the fuel trim , OPEN means the system is running a predefined mixture, so wait until it shows closed and also the temp is above 200. those will be some good readings for us, and instead of typing it out take a picture and upload here or i will send a link to a site you can drop files to.
ouch, ok, will do. :( wish you the best.,