Need help with misfire
10-08-23, 07:56 PM
#1
1st Gear
Thread Starter
Join Date: Oct 2023
Location: Pennsylvania
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Need help with misfire
Okay. I have a 1997 Lexus ES300 1MZFE3.0- non- VVT. I am experiencing a misfire.
Codes are:
P0301,P0303,P0305,P0171
PARTS THAT HAVE BEEN REPLACED TO DATE:
new fuel pump from Carter
New fuel filter 4 times
Cleaned fuel tank very thoroughly
New OEM injectors
New fuel damper on fuel rail
New upstream O2 sensors from Denson both
New crank sensor
New cam sensor
New NGK plugs Gapped correctly
cleaned mass air flow sensor thoroughly
New Air filter
checked for vacuum leaks with smoke pressure tester: outcome good.
New plug wires
New coils
cleaned plenum and proper install of gaskets
cleaned intake gaskets as well
cleaned throttle body
cleaned (IAC) idle air control unit
EGR is clean too.
The only things I have not done are the throttle position sensor, the (icm) ignition control module, or the mass air sensor. The iac was dirty and seemed to work but not sure.
The test computer read out shows O2 sensor bank1 at .680 and bank2 at .965 roughly. Downstream single .000.
fuel trim started at .000 across the board long and short term.
Then when it reaches optimal temp. The first trim falls to negative-18.3.
The engine Idles up when cold and drops to about1,070 rpm when warm. Then it drops to 775 rpm when shifting into drive or revs.
As you place your foot on the gas it pops,misfires and just has zero power but doesn't stall. I have triple checked everything from injector resistance: good. TO FUEL PRESSURE. AND SPARK. ALL GOOD. I ALSO REPLACED TIMMING BELT AND MADE SURE THE ENGINE IS SET TO TOP DEAD CENTER AND CAM POSITIONS ARE PERFECT. Oh. Engine will rev. Smoothly then misfires at about half throttle climbing rpm and falling. Once again no power under load. Load on engine is about 27% at roughly 1,070 to 2,000 rpm. I need help with this car. Never seen this before. Btw valves are good and cams look good too. Looked at all that when replacing all the upper gaskets. Oil is clean and antifreeze as well. Compression is an average of 168 across all cylinders at temp. 165°. Within a couple pounds. So that's not the issue. Has anyone had this same issue. Please help me.....
Codes are:
P0301,P0303,P0305,P0171
PARTS THAT HAVE BEEN REPLACED TO DATE:
new fuel pump from Carter
New fuel filter 4 times
Cleaned fuel tank very thoroughly
New OEM injectors
New fuel damper on fuel rail
New upstream O2 sensors from Denson both
New crank sensor
New cam sensor
New NGK plugs Gapped correctly
cleaned mass air flow sensor thoroughly
New Air filter
checked for vacuum leaks with smoke pressure tester: outcome good.
New plug wires
New coils
cleaned plenum and proper install of gaskets
cleaned intake gaskets as well
cleaned throttle body
cleaned (IAC) idle air control unit
EGR is clean too.
The only things I have not done are the throttle position sensor, the (icm) ignition control module, or the mass air sensor. The iac was dirty and seemed to work but not sure.
The test computer read out shows O2 sensor bank1 at .680 and bank2 at .965 roughly. Downstream single .000.
fuel trim started at .000 across the board long and short term.
Then when it reaches optimal temp. The first trim falls to negative-18.3.
The engine Idles up when cold and drops to about1,070 rpm when warm. Then it drops to 775 rpm when shifting into drive or revs.
As you place your foot on the gas it pops,misfires and just has zero power but doesn't stall. I have triple checked everything from injector resistance: good. TO FUEL PRESSURE. AND SPARK. ALL GOOD. I ALSO REPLACED TIMMING BELT AND MADE SURE THE ENGINE IS SET TO TOP DEAD CENTER AND CAM POSITIONS ARE PERFECT. Oh. Engine will rev. Smoothly then misfires at about half throttle climbing rpm and falling. Once again no power under load. Load on engine is about 27% at roughly 1,070 to 2,000 rpm. I need help with this car. Never seen this before. Btw valves are good and cams look good too. Looked at all that when replacing all the upper gaskets. Oil is clean and antifreeze as well. Compression is an average of 168 across all cylinders at temp. 165°. Within a couple pounds. So that's not the issue. Has anyone had this same issue. Please help me.....
10-10-23, 12:54 AM
#2
Pole Position
Hello,
How did the issue first begin?
Where did you get all the parts, is it a reputable location (dealership), or eBay/Amazon?
For better or for worse, to me this issue sounds like one of so many cases where people just start throwing parts on problems, causing dozen other issues to appear for any one that's solved, here is a recent thread on this subject. The main issue is that you start to dilute the initial problem, adding unknown variables, and worst of all, trapping you into an illusion that if the part is new, it is indeed working, and does not require a revisit, even if it is a number one suspect.
The thing is that people tend to miss how much OEM parts can run for, a perfect example are Injectors, which can easily run for about $200 each, meaning that replacing all 6 of them with OEM can quickly and definitively total your vehicle, coils are not cheap either, going for about $100 each. It seems like if everything on the list that you mentioned is indeed high quality OEM parts, you would be looking at a price high enough to get a low mileage 4th-gen ES, maybe even a post-facelift one.
The issue is most definitely somewhere in one Specific component, you will never get everything to fall apart in one instance, components Only fail in sequence, unless if you possess the same logic as may Toyota owners suffer from, where the car is so resilient it doesn't require any maintenance, so they sit and let the faults accumulate until the wheels start falling off, what they miss is the fact that even if a car can tolerate the beating, it doesn't mean it will last in it.
If you still have all the old parts, I would get them back into a car and see what happens, even if nothing changes, you will have a reference point to go from. Next step would be to start actually Checking the components instead of swapping them at random, starting with items specific to Bank 1, here is a thread where the similar issue was caused by O2 sensor, even though the owner did replace it recently.
Hope this helps and best of luck!
How did the issue first begin?
Where did you get all the parts, is it a reputable location (dealership), or eBay/Amazon?
For better or for worse, to me this issue sounds like one of so many cases where people just start throwing parts on problems, causing dozen other issues to appear for any one that's solved, here is a recent thread on this subject. The main issue is that you start to dilute the initial problem, adding unknown variables, and worst of all, trapping you into an illusion that if the part is new, it is indeed working, and does not require a revisit, even if it is a number one suspect.
The thing is that people tend to miss how much OEM parts can run for, a perfect example are Injectors, which can easily run for about $200 each, meaning that replacing all 6 of them with OEM can quickly and definitively total your vehicle, coils are not cheap either, going for about $100 each. It seems like if everything on the list that you mentioned is indeed high quality OEM parts, you would be looking at a price high enough to get a low mileage 4th-gen ES, maybe even a post-facelift one.
The issue is most definitely somewhere in one Specific component, you will never get everything to fall apart in one instance, components Only fail in sequence, unless if you possess the same logic as may Toyota owners suffer from, where the car is so resilient it doesn't require any maintenance, so they sit and let the faults accumulate until the wheels start falling off, what they miss is the fact that even if a car can tolerate the beating, it doesn't mean it will last in it.
If you still have all the old parts, I would get them back into a car and see what happens, even if nothing changes, you will have a reference point to go from. Next step would be to start actually Checking the components instead of swapping them at random, starting with items specific to Bank 1, here is a thread where the similar issue was caused by O2 sensor, even though the owner did replace it recently.
Hope this helps and best of luck!
10-10-23, 06:35 AM
#3
Arsenii, well said.
New Toyota/Lexus owners may be unfamiliar with just how durable and long lasting OEM parts are. My original alternator, with 286,000 miles, finally conked out.
Also, if you plan on diagnosing and performing the work yourself, invest in the OEM repair manual. HERE is the source from Toyota.
New Toyota/Lexus owners may be unfamiliar with just how durable and long lasting OEM parts are. My original alternator, with 286,000 miles, finally conked out.
Also, if you plan on diagnosing and performing the work yourself, invest in the OEM repair manual. HERE is the source from Toyota.
Last edited by fortitude; 10-10-23 at 06:45 AM.
Thread
Thread Starter
Forum
Replies
Last Post