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Ask Chad Farhat Your Own Question
Chad Farhat
Chad Farhat, ASE Certified Technician A6 - Electrical / Electronic systems A7 Heating / Air conditioning systems
Category: Lexus
Satisfied Customers: 2544
Experience:  Owner at Carolina Auto Service & Sales , 20 years Experience in Foreign & Domestic Vehicles
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I need help with a 1997 Lexus ES300 multi Misfires

Customer Question

I need help with a 1997 Lexus ES300 multi Misfires
Submitted: 8 months ago.
Category: Lexus
Expert:  Chad Farhat replied 8 months ago.

vHi, I'm Chad ,Welcome To JustAnswer, I'm reviewing your question and I will be be posting a replay ASAP

Expert:  Chad Farhat replied 8 months ago.

is there a check engine light on ?

have you had a diagnostic scan and retrieved the fault codes ?

Please let me know

Thank You
Chad Farhat
ASE Certfied Technician

Customer: replied 8 months ago.
Ok So here is the run down. It is important to know that I bought this car to see if I could fix it. The old owner is a friend of mine and he has thrown a lot of money at the problem. I think there is a short somewhere or a sensor is bad.1. I have an OBD II reader and can provide live data. It gives a general misfire code. I have changed the coils, wires, o2 sensors. The car will start right up but runs rough at idle. As you get higher in the RPM it smooths out.2. The misfire moves as if the computer is confused. I have had the computer rebuilt with no change. You can move coils, plugs but can not find and reason why it misfires.3. I have tested the cams shaft sensor it reads about 1300 ohms which seems in spec.4. I have verified the coils are functioning. There is 3 coils with 2 hot wires each. One is constant and the other is not as it it telling the coil to fire. And I have verified this.5. I have also check the fuel and replaced it.6. I have gone through the vacuum and can not seem to find a leak.7. There is a small canister that seems to connect to the EGR valve is not connected and one of the 1/8 port is broken off.
The person who owned the car before did not know where it went. I can send a photo if needed.
Expert:  Chad Farhat replied 8 months ago.

what is the mileage ?

is there any fault codes m=now ?

have you checked the timing ?

send photo please

Thanks

Chad

Customer: replied 8 months ago.
The car has about 245,000 miles.
I have not checked the timing but I know the timing belt has been done twice.
Also the misfire rotates but both sides like right now it is 1,2,4,5 and 6.There are no other codes other than the misfire codes.
I will send a photo of the part shortly.
I will also send the live data.
Expert:  Chad Farhat replied 8 months ago.

ok sounds good.do we have a vacuum leak , have you tried spraying starting fluid around the intake and see if engine surges?

Check fuel pressure i send you fuel specs?

check timing , i sent the marks on timing ?

https://www.dropbox.com/s/c9wnwzeleg0rl3t/File%20Jul%2017%2C%204%2039%2030%20PM.png?dl=0

https://www.dropbox.com/s/lvjlwmilbrvs5po/File%20Jul%2017%2C%204%2039%2037%20PM.png?dl=0

https://www.dropbox.com/s/7ty36kr6mc5fera/File%20Jul%2017%2C%204%2039%2043%20PM.png?dl=0

https://www.dropbox.com/s/98443o6ukwozjhg/File%20Jul%2017%2C%204%2039%2050%20PM.png?dl=0

https://www.dropbox.com/s/rwl9d4ih1mnairf/File%20Jul%2017%2C%204%2039%2056%20PM.png?dl=0

Please check these things and let me know

Hope I was Helpful to you

A Positive Rating is Much Appreciated

This Post will stay open for you to come back and ask me any follow up questions you may have on this issue even after you rate me

Chad Farhat
ASE Certified Technician

Customer: replied 8 months ago.
Could this also be caused by a crank shaft sensor or knock sensor that is not coding but may be bad?
Expert:  Chad Farhat replied 8 months ago.

a crank sensor yes , but you said no code , you can take out the crank sensor and ohm it out , you should see resistance

a knock sensor will not cause the multiple misfire that way

Customer: replied 8 months ago.
Ok so sprayed carb cleaner on intake manifold and vacuum hoses no change.
I check the timing marks and I think they are dead on maybe off by the width of a piece of paper.
I reset the codes and here is what I am getting
misfire 1,2,3,5,6
Here are some photos.... First is the freeze data
Customer: replied 8 months ago.
Here is the live data
Customer: replied 8 months ago.
Any thoughts
Expert:  Chad Farhat replied 8 months ago.

what is the O2 sensor doing staying at 0.05 or fluctuating ? B2 S1

you have 17 % of fuel ratio adjustment the pcm is doing almost max out on one bank the pcm adding fuel

the other bank it is - 17 % , pulling fuel away on the other bank ?

what is fuel pressure ?

compression test ?

Expert:  Chad Farhat replied 8 months ago.

is fuel pressure 44 to 50 psi at idle ?

Customer: replied 8 months ago.
I will check the o2 sensor.
I do not have my fuel pressure or compression kit at the house.
I will see if I can borrow one quickly.
Expert:  Chad Farhat replied 8 months ago.

that is okay , the post will stay open so if you cant do it today , tomorrow, but i m here til 12 pm

I will help you solve it, since you seem you know how to check, the 245 k miles concerns me and tell what previous owner attempted to do to fix ?

what started his problem

Customer: replied 8 months ago.
The problem started with the misfires
The mechanic he took it to said it needed a tune up. So he changes the 3 coils, plugs, and wires.
It still was misfiring. The mechanic then said that he thought the computer was bad because compression was good and it was not giving any other codes other than the misfire. The computer was sent in and rebuilt. He then changes the O2 sensor, cam shaft sensor and I am not sure of anything else.
Customer: replied 8 months ago.
he gave up and I am a glutton for punishment. But the car is in good shape and I am in it so far about $600 with parts ( bought another coil, so vacuum hoses and the cost to talk to you) and cost of car.
Expert:  Chad Farhat replied 8 months ago.

your funny .lol

how about the ckp crank shaft sensor ?

get those readings please and lets go from there

Chad (aka -Customer

Customer: replied 8 months ago.
Lastly I work tomorrow from 8 am to 5 pm eastern time. Will you be available after that?
Expert:  Chad Farhat replied 8 months ago.

yes till 12 pm tonight and tomorrow from 10 am till 12 pm.

now Tuesday i will be traveling , but back online Wednesday night late, then till rest off week

may i ask you mentioned the 3 coils you checked about having power and ground, how about the other 3 .

also backprobe the injectors for me , test light lead on positive side of battery terminal and stick in back connector of injector ,on the ground wire , does the test light pulsate

and if does, notice the brightness is dim ?

Expert:  Chad Farhat replied 8 months ago.

i just looked at you short term fuel trim not long term , it is at 19 %!!! , so that is immediate adjustment from pcm it is starving for fuel on one bank and too much fuel on the other bank

we know that for sure based on the readings on the scanner .

you maf sensor reading is at 0.75 , can you tell me what is it if you can drive it and , what is that number of maf volume number when the car changes gear from 2nd to 3rd .

Customer: replied 8 months ago.
The car only has 3 coils that directly connect to 2,4, and 6. The coils then have a secondary connection for wires to connect 1,3,and 5. The coils have no ground wire and only 2 hots. With a test light I am able to see a very quick pulse on the one line, and a constant power on the other. All 3 seem the same in brightness and rhythm.As for the injectors this may be hard to do the back 3 without taking off the intake manifold.And I called the old owner......All the injectors were changed.I will pull the crank shaft sensor and see what it reads.
Customer: replied 8 months ago.
Testing the MAF while driving may be hard as i have a flat tire but let me see what I can do.
Should I try to do this before testing the crank shaft?
Expert:  Chad Farhat replied 8 months ago.

no test ckp sensor first ?

Expert:  Chad Farhat replied 8 months ago.

how about the back 3 coils ?

Customer: replied 8 months ago.
There is no back 3 coils, Only the front three
Expert:  Chad Farhat replied 8 months ago.

oh sorry yours is 97 your right .

Customer: replied 8 months ago.
I am going to take out crank shaft sensor.
Be back in like 20-30 mins
Expert:  Chad Farhat replied 8 months ago.

ok

Customer: replied 8 months ago.
warm the crank shaft sensor is reading 002 or 0.02 out of the car.
I assume it is bad? But for some reason not throwing the code?
Expert:  Chad Farhat replied 8 months ago.

yes based on spec it is .

a ckp sensor and mass air flow sensor sometime dont throw check lights on you have to test

Expert:  Chad Farhat replied 8 months ago.

Please dont forget to rate me before you exit , A positive rating is much appreciated

Let me know if you need anything else

Chad farhat

ASE Certified Technician

Customer: replied 8 months ago.
I will pick up the part tomorrow and put it in.
I will let you know how it goes.
Expert:  Chad Farhat replied 8 months ago.

ok

Customer: replied 8 months ago.
I guess i was wrong. Changed the crackshaft sensor and no change.
I retested the old one and I must have done it wrong.
I did look at the maf and at idle it reads 0.66 if you hold the idle at 2,000 ppm it goes up to 1.56
Expert:  Chad Farhat replied 8 months ago.

you need 5 at idle minim for maf sensor

you reading grams per seconds right

Customer: replied 8 months ago.
I will check I will also try to clean it out.
Expert:  Chad Farhat replied 8 months ago.

yes do that let me know , i will be off line till tomorrow late

but do reply back and when I log back in i will see your reply

Chad

Customer: replied 8 months ago.
it is lb/m
Customer: replied 8 months ago.
the conversion looks correct.
But the fuel is still off plus a lot on one side and - a lot on the other
Expert:  Chad Farhat replied 8 months ago.

let me know what happens

Customer: replied 8 months ago.
Did not work on this today and will not tomorrow.
Changing the fuel filter and getting a pressure test kit.
Let you know Thursday.
Expert:  Chad Farhat replied 8 months ago.

ok man sounds good, Thursday will be good for me too

Customer: replied 8 months ago.
Ok so here is an update of what i have done.1. Cleaned the intake and MAF.
2. Changed fuel filter ( Saw a slight improvement)
3. Tested TPS, Crankshaft position, and cam shaft sensor.
4. Sprayed throttle body cleaner on all vacuum hoses and intake manifold. no changeStill no change, but I am not able to test the fuel pressure because there is not a port. I will have to come up with something.
According to the live data it is still taking away a lot of fuel from side 1 and adding a lot to side 2. I though about changing the fuel pressure regulator but it is kind of pricey on a guess.
Expert:  Chad Farhat replied 8 months ago.

the fuel pressure check is important , and yes the fuel regulator will be next in line , but fuel pressure check is necessary to know its okay

then we can move to regulator, you can buy a special connection to hook it up inline with fuel system

Customer: replied 7 months ago.
I apologize for the delay. I had a mini stroke...but I am better now.
I am sorry but I need to start over.
1996 Lexus Es300
Misfire codes 1,3,5, and 6
Changed:
Wires
coils
plugs
fuel filter
fuel pressure damper
cam shaft sensor
crank shaft sensor
O2 sensorsChecked
Compression
Timing by checking cam marks
vacuum leaks - Spraying water and carb cleaner several times
moved coils and fuel injectors to see if misfire will move and it does not.
ECU was sent out and checked by ECU company found not issues but I guess still charged me to clean it up.It seems to run better cool. It won't throw out codes until its warm.
I do have a OBD II code reader with def and live data.Any thoughts? The last thing to check I can think of is the fuel pressure but there is no test port and I am not
sure how I can tap into it as there is no flexible hoses except the one that attaches to the fuel filter. I am afraid to cut
it because it has a special quick disconnect to the filter. And the exhaust seems to smell like sulfur.
Expert:  Chad Farhat replied 7 months ago.

hey i m sorry to hear about your stroke , i m glad you okay now & you are back :)

1-the exhaust catalytic system is original to the car , if it is clogged it will act up when it heats up, the car runs better when cold since the pcm uses the maf, ect etc.. sensors to run the car cold when it gets hot the o2 sensor takes over , so if the catalytic is clogged when hot it will start to acts up , since the sensors are reading correctly but the Catalytic is not letting it breath right .

2-next will be changing fuel pump, it is rare on Lexus to go out , dont cut line , it has special adapter to test that system

Let me know if you need anything else on it ,if you are good , Please Kindly rate me.

Hope I was helpful to you &

A Positive Rating is Much Appreciated

This Post Will Stay Open for You To Come back and Ask me Any Follow Up Question You May have on this issue , even after you rate me

Thank You

Chad Farhat
ASE Certified Technician

Customer: replied 7 months ago.
Is there a way I can test the catalytic converter?
Expert:  Chad Farhat replied 7 months ago.

The only way i know how to do it is by looking at a scanner live data fuel trims

if you had a laser temp gun, you can measure the temperature, if it is bad , it will have high temperature like 600 700 degrees and up

but this test is not 100 % accurate .

but logically speaking at 245k miles and original so the possibility being clogged is good

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