qewani1

Getting miss fire codes related to cylinder 3,4 and 8

Could some guide me to cylinder locations

Ls400 2000 model

TMaxxTim

Cylinders 2,4,6,8 are on the Passenger side I believe, and 1,3,5,7 are on the driver's side. I have a 99 LS 400 and I just had a rough idle problem and misfire on 2,4,6,8 and it ended up being my OCV (Oil Control Valve) for the VVTi. I replaced the passenger side and it instantly fixed my issue along with improving the power-band and the engine is smoother overall now. I woulnd't be surprised if replacing my driver's side OCV helped even more.

I'd check those, you can pull them out relatively easily and use a screwdriver or golf tee to move the valve inside...if the valve springs back instantly, it's working fine, if there's any kind of resistance, it probably needs to be replaced.

Midengtoy

iTrader: (3)

I had the same issue on my SC400 and it just ended up being bad spark plug wires.

billydpowe

iTrader: (1)

try this, firing order, dont worry about plug wires, you dont have any, but you have a coil for each plug.. check it out or carry it to a pro (not dealer)

sha4000

iTrader: (1)

I don't think It's the OCV since it would most likely show misfires on all the cylinders in either bank. #3 is the second cylinder from the front on bank 1 which is the drivers side. 4 is the second cylinder from the front and 8 is the last cylinder in the back on the passenger side which is bank 2. I would check the spark plugs.

qewani1

I will try switching coils and will see if miss fire moves around to other cylinder or no

qewani1

i may change the engine, since fuel consumption is high on this engine and cant figure out why it miss fires

YoshiMan

That'a a bit of an extreme move for an engine with a simple misfire! What if you put a new engine in and it does the same thing?

sha4000

iTrader: (1)

Fuel consumption is probably high because of the misfire. It was most likely running bad before the light came on anyway. Like had been said buying another engine is a bit extreme.

randal

You do not mention the number of miles or miles since last spark plug change. Changing the plugs would be my next move. Its simple and inexpensive and a general maintenance item...depending upon when last done. If you do not know, just change them. Use a good brand or you can get into trouble. NGK, I believe.

Mocchan

I agree, 8 spark plugs shouldn't cost you more than $50. Even if you do need new wires/coil packs, it will be much cheaper than changing out the entire engine.

My car started misfiring last week (1996 LS400, 225k miles). Last time the spark plugs were even touched was 110k miles back in 2006... I got to work swapping them out with NGK Laser Platinums along with NGK Spark Plug wires as well as new ignition coils (since I don't have coil packs). This fixed all of my issues as well as improving gas mileage significantly. Pre-spark plug, wire, coil service, I was averaging 16MPG city and around 18MPG mixed. After the service, I'm now averaging around 19-20 city, 24 mixed. I couldn't be happier with the results.

I did forget to mention that while I was doing all this, I also cleaned the throttle body (around 1.5mm of carbon build up) and also seafoamed my vehicle before changing the plugs.

qewani1

I forgot to mention that Injectors were already replaced with OEM parts...
Car is having 333899 miles on the clock..
Any how yesterday i have cleaned throttle body & MAF sensor, swapped injector coils, then did ECU reset. drove the car and i got in pending codes P0155 (02 Sensor Heater Circuit).
Since its in pending codes i have cleared it, will drive the car to see if miss fire codes comes again or no.

My air inlet is broken and it has a hole, does that have any effects?

sha4000

iTrader: (1)

A vacuum leak is almost always a problem. Where on the inlet is the hole?

qewani1

I am away from home right now, i mean its broken with hole in highlighted area

Does have any effect?

YoshiMan

That looks like the part where the air is initially taken in on the front of the car... is it?

A hole in that wouldn't effect it, since its before the MAF sensor