Hi,
i just got in my car yesterday and it was idling rough and misfiring. a couple minutes later it aswell had cel flashing and gave me some codes...cylinder 2,4,6,8 misfiring and random misfire detected. no other than that yet.
i changed the spark plugs 2 weeks ago, ordered the coil packs yesterday. which other ways should i look at?
injectors or oxygen sensor? or is it a propable valve clearance issue, since my car drives with lpg?
car has 246 tkm and is running with lpg.

thanks for any input

 

Since you just replaced your plugs I would check to make sure everything you removed is still connected properly. Maybe something came undone.

 

I checked the vacuum lines, but could not find any big cracks, that could cause this. i ordered some tubing anyhow, as well as 2 oxygen sensors, since both #1 sensors have never been replaced on my car. also i ordered 2 used ocv's. today i removed the vent tube from bank 2 valve cover going to the inlet and found some yellow looking gunk inside it...don't know what that was, also the intake was kind of oily...??? never experienced that on a lexus...
also i ordered new coils, since these are still the first ones presumably, however i ordered some aftermarket ones.

i thought that maybe my valves are getting tight, since the lpg system in my car. however, the fact that the fault codes were only on bank 2 and not only on one cylinder makes me doubt that.
today i also had p0175 code...i can crosscheck the maf with my old one, however i replaced that because it was running jerky. can the maf be defective again after only 40 tkm???

 

Just another question, did anyone ever have an oxygen sensor fault, without an o² sensor fault code that also caused misfires and rough idle?

 

yesterday i had the p0175 (running rich) fault. this morning when i drove to work, i had the p0300 (multiple misfires) again. still no other information.
i am now looking at idle air control..is this an option? had the misfires also during driving and felt hesitation. the cel besides that, came on at a stoplight and it was flashing. cleared it directly..
yesterday i cleared the vcs light. when i started the engine this morning it was ok, starting revs at around 1500 rpm. drove off, vsc came on directly, 2-3 min later the engine ran rough and had hesitations. when the engine is then warm, it feels better. still have wet exhaust from the unburnt fuel.

it would be nice if someone could chime in...

 

Could be the VVT solenoid for that bank but you should get a code for that...

Good luck

 

Have you done anything with the injectors? Injector cleaner at the least, but swapping them between banks would tell you for sure. Worse case you could swap a whole lot of parts between the two banks and see if it follows to the opposite bank. A leak down and or a compression test would help to verify the engine hard parts are still sealing as well, but won't always pick up a minor issue. I hate to say it but I recently had this issue with our 4Runner. I got frustrated enough to pick up a used engine and swap all of the sensors, injectors, coils etc and it still had a random misfire when cold. Luckily in that case I already had a spare motor to throw in it rather than actually spending the time searching for the mechanical issue.

 

actually the injectors do not even matter, since the lpg System has separate injectors. i did aswell swap out the ocv's, but it did not do anything. by they way, i could not find the ocv's Filters. i still have 2 spare no 1 o2 Sensors here, and i ordered Spark Plugs and Coils. denso Plugs and Aftermarket Coils. but I am assuming it is some sort of Sensor...could it be a camshaft sensor?

 

Camshift sensor is a possibility, but I would think that would present as a random misfire or effect all cylinders.

 

This morning i had misfires and codes as follows: P0300, P0302, P0308, P0301, P0303, P0306.
Translates into multiple misfires, cylinder 2, 8, 1, 3, 6

So this is the first time it happened on both banks. what now? could it be possible that the timing belt jumped? but powerwise everything feels normal, and after a couple of minutes misfires in idle get better, under driving conditions it is ok and the cel flashes only in the first minute, so that rules the timing belt out. also i don't think its a mechanical issue.

how many camshaft sensors are there? also i would think that if the filter from the ocv is clogged, there is no fault code for the ocv, since the solenoid works, but the oil supply is not monitored, rendering the system unfunctional...correct? how do i get access to that filter?

 

So, Update...
yesterday i replaced the coil packs, found some slightly oily plugs, cleaned them. fitted the new coil packs, took it for a test drive...still the old problem.

So, when i start the car, it is actually ok for a couple of minutes, it is when it warms up that it starts to shake and rough idle. on the way to work this morning i had codes for cylinder 2, 4, 7 and running rich.