ManuelFdz

hi guys, im a owner of a IS350 2006, and i am having a weird problem right now.. first off, lets start a month ago when the car was misfiring cyl #2, i bought a Coil Replacement for that cyl and replace it, still the misfiring was there, so i proceed to order a set of spark plugs, the misfiring was there before the spark plugs change, it was minimal but you can still feel it was having a rough idle..

then, yesterday i went to my mechanic to do the spark plugs, and get rid of the annoying misfire and CEL, and then the problems start.. -_-
after the Spark plugs change the car didnt throw any CEL, but OMW home the car start to rough idle, and if i didnt gave it any gas it would stall, i went home and spend the night, the day after (today) i went to the shop, the car on the way throw a code (system to rich). it didnt show the misfiring code that was the main issue before.. now the car is rough idling and stalling, it have a huge loss of power, and the best part is that its not throwing any code so we dont know what is happening..

we change the MAF Sensor to see if that was the problem but it kept doing the same thing, clean up the fuel filter and checked the fuelpump and everything was how it should be
i dont know if you can mess up the firing order when changing sparkplugs, but any advice will be great,

thanks in advance!

knyg

Seems like a leak. You should probably check the intake manifold gasket. Also check if you screwed everything in tight when you changed your spark plugs.


also, do you have any modifications in your engine bay? I had my oil catch can top notch loose and was giving me problems that I changed all my spark plugs and coils. When all I had to do was tighten my OCC nut.

ManuelFdz

ill check for leaks but the intake manifold wasnt even touch, we'll check everything related to the sparkplugs tomorrow morning, and no i do not have any mods, just an intake F Sport, that was remove to change the sparkplugs, what happened to your oil catch can?

AiRuss

iTrader: (1)

Check through this recent post:
https://www.clublexus.com/forums/is-...ark-plugs.html

Mrfix

This problem with cylinder 2 was an existing issue before you did anything. So you swapped out the coil, spark plug and the problem remained. It might be a timing issue but that would probably throw codes across multiple cylinders. If all your wiring is is good and there are no broken wires or connectors (sometimes things happen when you move wires around) I would consider checking the injector for that cylinder and see if it needs cleaning. It could be coincidence but you might be experiencing something failing in the fuel system and cylinder 2 was your canary in the coal mine.

Good luck let us know what you come up with.

ManuelFdz

the problem still persist, it is not misfiring when driving anymore, but it is misfiring when cold start, and its throwing p0300 (multiple misfire) p0302 (misfire cyl 2) and p0304 (misfire cyl 4), the sparkplugs are new OEM, replaced the coil that was failing before (cyl #2), then now we replaced again coil 2 and 4, and still throwing p0300, my mechanic suggest maybe the sparkplugs are not OEM and maybe a ripoff, and hes gonna try with a new set of sparkplugs. i really dont know whats the next step if the sparkplug change again does not fix it

Mrfix

[QUOTE=ManuelFdz;10059069]the problem still persist, it is not misfiring when driving anymore, but it is misfiring when cold start, and its throwing p0300 (multiple misfire) p0302 (misfire cyl 2) and p0304 (misfire cyl 4), the sparkplugs are new OEM, replaced the coil that was failing before (cyl #2), then now we replaced again coil 2 and 4, and still throwing p0300, my mechanic suggest maybe the sparkplugs are not OEM and maybe a ripoff, and hes gonna try with a new set of sparkplugs. i really dont know whats the next step if the sparkplug change again does not fix it[/QUOTE


Have you checked the fuel system? Is your fuel pressure ok? Are your injectors clean? I can't imagine your plugs are bad. I still think you might be having a fuel problem where it is to lean at idle.

ManuelFdz

i will advice that to my mechanic MrFix, we pulled out the sparkplug we replace 3 days ago, and this is how they were
Sparkplug #6

and sparkplug #2 and #4

how do i check the fuel system? we checked the pressure of the fuelpump and it was perfect, i dont know if youre talking about the same thing.. sorry for my ignorance guys hehe

i guess if it was a bad injector it would be constant the problem, but the car is running great, the codes are thrown when the car is cold, or you start it after an hour without using it

Mrfix

Another question...have you had the recall work done on this car? I presume it is a US car that was imported to the Island.

ManuelFdz

which one of them? in fact i had a few recalls done last year

2013FSport

iTrader: (2)

First off, don't assume all new parts are 100% good. Even new plugs and new coils can be deffective.

Did the mechanic verify the gap on the new plugs?

The random misfire is a huge concern. If it were mine I would start with a fresh set of new Denso plugs and move coil pack #2 to cylinder 1 for example. Does the misfire follow the coil pack? Does cyl#2 still have a code?

If yes, check the wiring of coil #2. Do an engine compression test and verify all holes are equal. The dark plug #2 looks to have fuel but no spark or low compression hence the incomplete burn and carbon deposits.

You might also verify the crank pickup sensor connection is good, clean, not burned, or corroded.

Also run some injector cleaner through it.

Gville350

iTrader: (10)

In the pic with the two spark plugs, one has ALOT of buildup on the end. Do you burn oil? Do you find yourself putting in a quart of oil or more during oil changes?

2013FSport

iTrader: (2)

Also, how is this vehicle used? Does it mainly do short trips of 3 - 5mi or less? Does it ever get on the freeway for long runs of 30min or more?
Last question, does it ever get opened up where it might be pulling >4k RPM for more than say 30 seconds?

If you still have the plugs we need to see the insides where the porcelain is. Where the tip meets the ground strap. Like so.... Notice #5 is like the rest but she burns no oil in 5000mi and has since cleaned up her act...

2013FSport

iTrader: (2)

What fuel grade do you use?

Concern here about plug #2 almost looks like detonation is flaking the carbon off. The porcelain is most clean like its up to temperature but that is an odd pattern. Wild guess but if the coil misfires = black carbon look.
If the port injection FI is off line or intermittent, it could make the cold misfire and cause detonation from being lean...

Then you look at #4 with its clean body but the burn temperature is low so the porcelain is not burning off the fuel deposits....

Compression test and get some diagnostic software to look at fuel trims, ignition adavance under load, and spark retard (knock sensor active). Something is very odd here.

MikeFig82

iTrader: (13)

You said you had the F sport intake? Check all hoses again. Make sure they are secure. If you overtighten the hose clamps you can crush the pipe and not be sealing well.