princess_pudy Posted May 27 Share Posted May 27 So I'm getting failure all on one side of the motor I believe mz are 1,3,5. 2,4,6. Regardless is this common for coils to failure like that? I would believe it's a wiring issue but the reader is reading different amounts of misfires in each cylinder and none are 100% misfiring so it's intermittent. 4,6 were 40/43 but 2 was 12 out of 269... Ignites (estimate it was 250+ for sure) assuming it also takes each cylinder ignition into account so 95 misfires out of 269 ignites. Quote Link to comment Share on other sites More sharing options...
RX400h Posted May 28 Share Posted May 28 Quote It’s not common for all the coils on one side of the engine to fail simultaneously. If all cylinders on one side are misfiring, it could be due to a few reasons: Ignition Coils: Ignition coils can fail, but they usually fail individually. Wiring Issues: A bad connection in the coil harness or the fuel injection harness could cause multiple misfires. Fuel Pressure: Low fuel pressure is another common source that would cause multiple misfires simultaneously. Spark Plugs: If no leaks are found, the next step is to replace the spark plugs on the misfiring cylinders. Given the intermittent nature of the misfires and the different amounts of misfires in each cylinder, it’s possible that there might be multiple issues at play. It’s recommended to diagnose the problem systematically: Check for Intake Leaks: Start by checking for intake leaks. Test the Coils: Turn on the engine and unplug each coil one by one to see if there is a change in the sound or rpm of the engine. If there is no change, that means the coil is bad and needs to be replaced. Swap the Coils: Swap the bad coil with a good one to confirm that the problem is not the spark plug, the injector, or the wiring. Replace the Coils and Spark Plugs: If the coils are indeed bad, replace them. It’s a good idea to replace all the coils at the same time, and also replace the spark plugs if they are old or worn out. Remember to clear the check engine light after the repairs and monitor the engine performance. If the problem persists, more tests need to be done to diagnose the problem. Please consult with a professional mechanic to ensure proper diagnosis and repair. Good luck! Quote Link to comment Share on other sites More sharing options...
little willie Posted May 28 Share Posted May 28 2009 lexus ruff car kinda shaking when idileing an at stop when in gear only run smooth as hell when driving Quote Link to comment Share on other sites More sharing options...
meowge Posted May 28 Share Posted May 28 Obd read Ignore the knock sensor code. I was having the issue before that and the code was caused by me and had nothing to do with the miss at the time I'm getting same issue. I can barely make it up a slight incline and it takes me a solid 5 minutes to get up to the speed limit sometimes. If I slightly press gas it will speed up very slowly if I press a bit harder it bogs down and starts to slow down even on flat surfaces. I've changed the coils. I hear the VVTI oil control value is a common issue but I always hear O2 but I'm not getting a code oh 2001 Lexus rx300 Quote Link to comment Share on other sites More sharing options...
meowge Posted May 28 Share Posted May 28 8 hours ago, RX400h said: I switched coils it seemed as if it was running a bit better but problem gets worse as the car warms up it seems. I played around with some functions. Such as activating VVTI solenoids at idle and bank1 stalled engine instantly. But bank to the rpms actually went up roughly 200 and 10 seconds later it jumped to 2k rpms. Quote Link to comment Share on other sites More sharing options...
RX400h Posted May 29 Share Posted May 29 On 5/28/2024 at 1:35 AM, meowge said: I switched coils it seemed as if it was running a bit better but problem gets worse as the car warms up it seems. I played around with some functions. Such as activating VVTI solenoids at idle and bank1 stalled engine instantly. But bank to the rpms actually went up roughly 200 and 10 seconds later it jumped to 2k rpms. Have you also considered any of these possibilities? Quote Here are some potential causes and solutions: Clogged Air Filter: If the air filter is dirty, it can negatively affect the performance of the engine, as less air passes through the dirty filter which suffocates the engine. Replacing the filter on your RX takes a few minutes and does not require any special knowledge. Dirty or Faulty Mass Air Flow Sensor (MAF): A defective or dirty MAF in your Lexus RX can result in loss of power, uneven engine running, erratic idling, misfires, poor exhaust emission values including black smoke. If the MAF sensor is defective or dirty, it does not send correct measured values to the control unit of RX. Clogged Fuel Filter or Fuel Pump Malfunction: These can also cause slow acceleration. Faulty Oxygen Sensor or Dirty Throttle Body: These are also common causes for slow acceleration. Worn Spark Plugs or Clogged Catalytic Converter: These can also lead to slow acceleration. Dirty Fuel Injectors, Dirty Engine Valves, and Combustion Chamber Deposits: These can cause engine hesitation, power loss, and sluggish acceleration2. A potential fix could be using a fuel system cleaner product like Chevron Techron Concentrate Plus. Low Transmission Fluid: This can also cause sluggish acceleration. Ensure proper fluid levels for optimal acceleration. Quote Link to comment Share on other sites More sharing options...
meowge Posted May 29 Share Posted May 29 53 minutes ago, RX400h said: Have you also considered any of these possibilities? Thank you for the recommendations. I loosened one of the exhaust connectors to see if letting more exhaust gases out would change anything but it did not end. As for the clodcat, I loosened the exhaust pre-cat. I'm sort of leaning towards possibly a dirty injector because as I was showing my friend what was going on, I went and unplugged bank 2 injectors and only one of the injectors created a noticeable change with the engine running. While the other two injectors had little or no change as I unplugged them, so I'm assuming they're either dead or clogged or there's an issue in the circus somewhere. I don't have a multimeter so it's going to be difficult to test but I do have a ODB scanner that offers active testing and I'll probably just pull the injectors and activate the function and see if they start pulsing Quote Link to comment Share on other sites More sharing options...
meowge Posted May 29 Share Posted May 29 P another thing I've been noticing is as I've been driving it more. The drivability has actually increased dramatically from when I first purchased the vehicle so that makes me leave that. Maybe I'm lodging something loose within the injectors but I will keep you updated Quote Link to comment Share on other sites More sharing options...
meowge Posted May 29 Share Posted May 29 Yes, looking like it was the injectors after all. I cleaned two of them four and six and rescanned and only cylinder two still had the misfire code active on it which I'm about to take off that one and clean it as well. I'm not sure why I didn't do it in the first place. I figured it was the only one working from my initial plug test so I just Left to be Quote Link to comment Share on other sites More sharing options...
meowge Posted May 31 Share Posted May 31 Sorry all. I was wrong. Turns out the bank2 cat was completely destroyed lodging the honeycomb down into the down pipe. I realized this by loosening the bolts from cat to header just a couple turns and got power back with no misfires anymore. 2 Quote Link to comment Share on other sites More sharing options...
RX400h Posted May 31 Share Posted May 31 Congrats on discovering the culprit! 👍 Quote Link to comment Share on other sites More sharing options...
meowge Posted June 1 Share Posted June 1 Yes, thank you. Bought it for 1k last week because the guy didn't want to diagnose the problem. 187k miles interior great condition outside cosmetic ok/good condition. Fix cost me 20 dollars for a harbor freight tool set and a willingness to learn. Overall I figure it was a good deal. Now I have a beautiful piece of engineering mastery(1mz) and a ride that does fake wood grain tastefully haha. My friend has an RX also and we might start one of those riding clubs named soccer mom squad (neither of us moms, or women) out of irony 1 Quote Link to comment Share on other sites More sharing options...
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