08 Is250 awd misfire #3 P0303 help
01-24-21, 02:24 PM
#1
Driver School Candidate
Thread Starter
08 Is250 awd misfire #3 P0303 help
Hi guys...
I tried searching all over clublexus and google. Misfire on #3 cylinder P0303. swap coil around still get the same code P0303. I replaced the spark plugs with OEM ngk plugs and replace all coils since the car has 250k miles. the plug that came out of #3 cylinder had some oil residues on it... still the code came right back after clearing it. I check the wires for resistance from the coil plug to ECU... it came out fine. I even swap out a used ECU to see if it change anything.. still no luck. I did a compress test and they came out very good #1-200 , #2-200, #3-210, 4#-200, 5#-200, 6#-205. I even did walnut blasting on it to get rid of all the carbon build up. I then swap out all the fuel injectors with a remanufacture one from Denso.. still the same. I didn't check the resistance for the injector pugs to the injector module which I regret.. It is very difficult to get to those injectors. car seems to run a little better after new injectors. I'm running out of ideas.. all the wires looks fine, doesn't look like any rats got to it. My next step is driver injector module... I did lots of research but so far no luck.. Any help will be greatly appreciated..
thanks guys
I tried searching all over clublexus and google. Misfire on #3 cylinder P0303. swap coil around still get the same code P0303. I replaced the spark plugs with OEM ngk plugs and replace all coils since the car has 250k miles. the plug that came out of #3 cylinder had some oil residues on it... still the code came right back after clearing it. I check the wires for resistance from the coil plug to ECU... it came out fine. I even swap out a used ECU to see if it change anything.. still no luck. I did a compress test and they came out very good #1-200 , #2-200, #3-210, 4#-200, 5#-200, 6#-205. I even did walnut blasting on it to get rid of all the carbon build up. I then swap out all the fuel injectors with a remanufacture one from Denso.. still the same. I didn't check the resistance for the injector pugs to the injector module which I regret.. It is very difficult to get to those injectors. car seems to run a little better after new injectors. I'm running out of ideas.. all the wires looks fine, doesn't look like any rats got to it. My next step is driver injector module... I did lots of research but so far no luck.. Any help will be greatly appreciated..
thanks guys
01-25-21, 09:49 AM
#2
Hi guys...
I tried searching all over clublexus and google. Misfire on #3 cylinder P0303. swap coil around still get the same code P0303. I replaced the spark plugs with OEM ngk plugs and replace all coils since the car has 250k miles. the plug that came out of #3 cylinder had some oil residues on it... still the code came right back after clearing it. I check the wires for resistance from the coil plug to ECU... it came out fine. I even swap out a used ECU to see if it change anything.. still no luck. I did a compress test and they came out very good #1-200 , #2-200, #3-210, 4#-200, 5#-200, 6#-205. I even did walnut blasting on it to get rid of all the carbon build up. I then swap out all the fuel injectors with a remanufacture one from Denso.. still the same. I didn't check the resistance for the injector pugs to the injector module which I regret.. It is very difficult to get to those injectors. car seems to run a little better after new injectors. I'm running out of ideas.. all the wires looks fine, doesn't look like any rats got to it. My next step is driver injector module... I did lots of research but so far no luck.. Any help will be greatly appreciated..
thanks guys
I tried searching all over clublexus and google. Misfire on #3 cylinder P0303. swap coil around still get the same code P0303. I replaced the spark plugs with OEM ngk plugs and replace all coils since the car has 250k miles. the plug that came out of #3 cylinder had some oil residues on it... still the code came right back after clearing it. I check the wires for resistance from the coil plug to ECU... it came out fine. I even swap out a used ECU to see if it change anything.. still no luck. I did a compress test and they came out very good #1-200 , #2-200, #3-210, 4#-200, 5#-200, 6#-205. I even did walnut blasting on it to get rid of all the carbon build up. I then swap out all the fuel injectors with a remanufacture one from Denso.. still the same. I didn't check the resistance for the injector pugs to the injector module which I regret.. It is very difficult to get to those injectors. car seems to run a little better after new injectors. I'm running out of ideas.. all the wires looks fine, doesn't look like any rats got to it. My next step is driver injector module... I did lots of research but so far no luck.. Any help will be greatly appreciated..
thanks guys
What do the fuel trims look like from bank 1 vs bank 2? And what are the O2 sensors showing?
The app OBD Fusion with the Lexus Toyota add on PID pack will give you HPFR data as well pulse width per injector..
If review of the above data shows nothing, you might plan on pulling the valve cover on bank 1 for inspection of cam, springs, rockers....
Abstract but is the hole completely dead? Like if you plug in a spare coil and plug outside of the engine, does it have the same rough idle? Does it buck and studder when pulling hills. Tell us about the drive quality with this misfire.
Be warned, you posted in the wrong section and your thread will likely be moved to the general 2IS section.
01-25-21, 02:07 PM
#3
Driver School Candidate
Thread Starter
What do the fuel trims look like from bank 1 vs bank 2? And what are the O2 sensors showing?
The app OBD Fusion with the Lexus Toyota add on PID pack will give you HPFR data as well pulse width per injector..
If review of the above data shows nothing, you might plan on pulling the valve cover on bank 1 for inspection of cam, springs, rockers....
Abstract but is the hole completely dead? Like if you plug in a spare coil and plug outside of the engine, does it have the same rough idle? Does it buck and studder when pulling hills. Tell us about the drive quality with this misfire.
Be warned, you posted in the wrong section and your thread will likely be moved to the general 2IS section.
The app OBD Fusion with the Lexus Toyota add on PID pack will give you HPFR data as well pulse width per injector..
If review of the above data shows nothing, you might plan on pulling the valve cover on bank 1 for inspection of cam, springs, rockers....
Abstract but is the hole completely dead? Like if you plug in a spare coil and plug outside of the engine, does it have the same rough idle? Does it buck and studder when pulling hills. Tell us about the drive quality with this misfire.
Be warned, you posted in the wrong section and your thread will likely be moved to the general 2IS section.
thank you for replying. Sorry for posting in the wrong place. First time posting. I do lots of reading here on my phone. Maybe a desk top version is better.
the o2 sensor reading is with in range. Nothing out of ordinary so I didn’t look deep into that.
will definitely download the OBD fusion app. Thanks for the recommendation.
I did a compression test and it’s good so I’m narrowing it down to fuel because I took the coil off and put on a spark tester and it was firing but not sure about the voltage or timing.
car shakes a lot and idles high around 1800 rpm.
no power going uphill. If I rev the engine from 2,000 to 5,000 rpm it sounds very smooth.
I found a used injector driver module for a very seasonable price so I’m gonna get it and swap it out and see what happens. I did lots of research on this module and seems like they don’t usually go bad.
could it be a programming issue ?
It’s hard to find a good technician in Seattle area.
even dealer I don’t really trust since I had a bad experience with them before.
01-25-21, 02:58 PM
#4
thank you for replying. Sorry for posting in the wrong place. First time posting. I do lots of reading here on my phone. Maybe a desk top version is better.
the o2 sensor reading is with in range. Nothing out of ordinary so I didn’t look deep into that.
will definitely download the OBD fusion app. Thanks for the recommendation.
I did a compression test and it’s good so I’m narrowing it down to fuel because I took the coil off and put on a spark tester and it was firing but not sure about the voltage or timing.
car shakes a lot and idles high around 1800 rpm.
no power going uphill. If I rev the engine from 2,000 to 5,000 rpm it sounds very smooth.
I found a used injector driver module for a very seasonable price so I’m gonna get it and swap it out and see what happens. I did lots of research on this module and seems like they don’t usually go bad.
could it be a programming issue ?
It’s hard to find a good technician in Seattle area.
even dealer I don’t really trust since I had a bad experience with them before.
the o2 sensor reading is with in range. Nothing out of ordinary so I didn’t look deep into that.
will definitely download the OBD fusion app. Thanks for the recommendation.
I did a compression test and it’s good so I’m narrowing it down to fuel because I took the coil off and put on a spark tester and it was firing but not sure about the voltage or timing.
car shakes a lot and idles high around 1800 rpm.
no power going uphill. If I rev the engine from 2,000 to 5,000 rpm it sounds very smooth.
I found a used injector driver module for a very seasonable price so I’m gonna get it and swap it out and see what happens. I did lots of research on this module and seems like they don’t usually go bad.
could it be a programming issue ?
It’s hard to find a good technician in Seattle area.
even dealer I don’t really trust since I had a bad experience with them before.
What do you know about it's repair history?
Did you do the plugs / w-blasting or someone else?
The high idle sounds like a vacuum leak. A misfire and High idle, again, vacuum leak but that would lesson as RPMs go up.
I'd suggest you make an account on www.alldatadiy.com and pull up the schematics looking for places the connection can fail. I'm not convinced its spark thats missing but it could be?
Did you buy it this way, has it ever ran right?
01-26-21, 08:17 AM
#5
Driver School Candidate
Thread Starter
Car ever spent time back east? Salt and electrical connections or any bad connection is a first guess vs more parts.
What do you know about it's repair history?
Did you do the plugs / w-blasting or someone else?
The high idle sounds like a vacuum leak. A misfire and High idle, again, vacuum leak but that would lesson as RPMs go up.
I'd suggest you make an account on www.alldatadiy.com and pull up the schematics looking for places the connection can fail. I'm not convinced its spark thats missing but it could be?
Did you buy it this way, has it ever ran right?
What do you know about it's repair history?
Did you do the plugs / w-blasting or someone else?
The high idle sounds like a vacuum leak. A misfire and High idle, again, vacuum leak but that would lesson as RPMs go up.
I'd suggest you make an account on www.alldatadiy.com and pull up the schematics looking for places the connection can fail. I'm not convinced its spark thats missing but it could be?
Did you buy it this way, has it ever ran right?
From the car fax. Looks like it’s been in west coast all it’s life. But all 4 rims are corroded. See the paint bubbling up on all 4 rims. no rust underneath the car.
I did the plugs, coils and walnut blasting myself. I was thinking If I miss a vacuum hose but I triple check myself. I spray(mist)break cleaner all around the intake manifold and try to listen in change in rpm. Nothing.
I bought the car this way. I like to work on cars when I have free time. And this car was about 30miles from my house so I bought it. Drove it on the highway up to 80mph. It just shakes at low rpm and no power going uphill.
I was able to turn off each cylinders fuel injector and #3 cylinder didn’t do anything when I turn it off and on. The rest will make the car shake even more and lower the rpm. So I’m pretty sure no fuel is going to #3 cylinder. When the weather is better I’ll check the harness from the injector to the control module for signal and power. Hopefully that’s the problem
thanks again for your help
greatly appreciated
01-26-21, 04:56 PM
#6
Although back-probing things like the ECM and the injector driver can reveal information, I'd highly recommend you get the schematics and go point to point. i.e. A single coil wire back to the ECM w the ECM unplugged. Same for the injector driver.
Based on your test of unplugging the injectors one by one, you could repeat that test with #3 coil disconnected. I think that would definitively say it is fuel vs spark.
You could also cheat injector #3 and power it yourself. Hmmm... this may be the best idea yet. Rig up for idle test and intermittently manually apply power to injector #3 for split second. If it picks up RPM, you know its something leading to that injector vs the injector itself.
Let's think about this. The ideal situation is digital switched control so you don't flood the hole and gather bad data. You need a one shot timer. Easy to make on a bread board or we may be able to buy something....
Based on your test of unplugging the injectors one by one, you could repeat that test with #3 coil disconnected. I think that would definitively say it is fuel vs spark.
You could also cheat injector #3 and power it yourself. Hmmm... this may be the best idea yet. Rig up for idle test and intermittently manually apply power to injector #3 for split second. If it picks up RPM, you know its something leading to that injector vs the injector itself.
Let's think about this. The ideal situation is digital switched control so you don't flood the hole and gather bad data. You need a one shot timer. Easy to make on a bread board or we may be able to buy something....
01-26-21, 09:25 PM
#7
Driver School Candidate
Thread Starter
Although back-probing things like the ECM and the injector driver can reveal information, I'd highly recommend you get the schematics and go point to point. i.e. A single coil wire back to the ECM w the ECM unplugged. Same for the injector driver.
Based on your test of unplugging the injectors one by one, you could repeat that test with #3 coil disconnected. I think that would definitively say it is fuel vs spark.
You could also cheat injector #3 and power it yourself. Hmmm... this may be the best idea yet. Rig up for idle test and intermittently manually apply power to injector #3 for split second. If it picks up RPM, you know its something leading to that injector vs the injector itself.
Let's think about this. The ideal situation is digital switched control so you don't flood the hole and gather bad data. You need a one shot timer. Easy to make on a bread board or we may be able to buy something....
Based on your test of unplugging the injectors one by one, you could repeat that test with #3 coil disconnected. I think that would definitively say it is fuel vs spark.
You could also cheat injector #3 and power it yourself. Hmmm... this may be the best idea yet. Rig up for idle test and intermittently manually apply power to injector #3 for split second. If it picks up RPM, you know its something leading to that injector vs the injector itself.
Let's think about this. The ideal situation is digital switched control so you don't flood the hole and gather bad data. You need a one shot timer. Easy to make on a bread board or we may be able to buy something....
I like your idea of jumping the fuel injector. I need to see if I can find a wire diagram to locate which wire is the power and signal wire leading to cylinder 3. Don’t want to go pull the fuel rail again but if I have to I’ll do it.
it’s been cold and wet in Seattle. I’ll wait for a nicer day to jump the injector. Maybe ask any of my friend for help reading the schematic.
Thanks again. Hopefully I can fix it soon.
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02-16-21, 01:14 AM
#8
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I have the same issue as you only I got a p0301 code for cylinder 1. I've replaced all 6 spark plugs twice. I've also replaced the ignition coil on cylinder 1 with no luck.
02-22-21, 09:45 AM
#9
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Thread Starter
Did you check your compression ? I didn’t have time to mess with it since my wife just gave birth. But I did check the injector control module. There is voltage coming out from the control module to the injector. I also check the resistance on the harness for possible broken wire. All good. I do have oil in the intake manifold so I replaced the pcv and added an oil catch can. I’m not sure if oil in the plastic intake manifold will destroy it. I will mess with it when I have more time and weather permits.
good luck. Please let me know if you find anything. Thanks
good luck. Please let me know if you find anything. Thanks
04-30-21, 10:47 AM
#11
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Thread Starter
Update on my misfire issue. It suffer from carbon buildup. Not sure why I still have good compression. I end up swapping a 3rd gen (2014) is250 engine in there and added an oil catch can. After a few trips with my wife with car seat in the back. This car is too small to have a car seat. After all the money I spend on it now wife wants me to get a mini van. 😔
04-30-21, 02:22 PM
#12
Update on my misfire issue. It suffer from carbon buildup. Not sure why I still have good compression. I end up swapping a 3rd gen (2014) is250 engine in there and added an oil catch can. After a few trips with my wife with car seat in the back. This car is too small to have a car seat. After all the money I spend on it now wife wants me to get a mini van. 😔
Any chance you looked into the port during this swap? How bad was it Carbonell up and why the single misfire code? Wait, didn't you say you walnut blasted it??? Hmmm....
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