Lexus

Lexus Troubleshooting Questions? Ask a Lexus Expert

Ask an Expert,
Get an Answer ASAP!

Lexus

My Lexus 400 is loosing current to all the 4 injectors on

Customer Question
Hi Don, My Lexus 400...
Hi Don, My Lexus 400 is loosing current to all the 4 injectors on the left bank (RHD) after the car runs 3-4 kms. Can you tell me what the problem could be?
Submitted: 2 years ago.Category: Lexus
Show More
Show Less
Ask Your Own Lexus Question
Customer reply replied 2 years ago
Also to note, once when the injectors were not working, we put off the ignition switch and restarted the car and it worked fine for a while.
Answered in 8 hours by:
9/12/2015
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago
sprinkles08
sprinkles08, ASE Certified Technician
Category: Lexus
Satisfied Customers: 23,258
Experience: ASE Master and Advanced level certified. Factory trained with 17 years dealership experience
Verified

Hello and welcome to JustAnswer!

There were two possible fuel systems, port and direct injection. Due to your symptoms I'm assuming you have port injection. If you're losing power to a whole bank of injectors then it's going to be a wiring issue. The injectors all receive power from the ten amp injector fuse and the engine controller pulses ground to actuate the injectors. A loss of power to some injectors only would have to be an open circuit in the wiring.

What fault codes set when this happens?

Ask Your Own Lexus Question
Customer reply replied 2 years ago
The fault code shows P0135-OXYGEN SENSOR HEATER CIRCUIT (BANK1 SENSOR 1)
OTHER STORED FAULTS WHICH HAVE BEEN ERASED ARE:
P1349 - VVT SYSTEM MALFUNCTION (BANK1)
P1645 - BODY ECU MALFUNCTION
I had the ECU checked, it seems to be ok.
If it is a wiring issue how come in cold start it works ok and only after driving a few kilometers current to all 4 injectors disappears and on switching off the engine and restarting the current comes back for a short while.
It would seem like a relay is cutting off on extended use and switching off the current and restarting it catches again.
Is there any relay in the system between the ECU and the injectors?
I have checked the wires to and from the injectors and they seem intact.
Also to note something that could be related. The Automatic Transmission is not in good shape. The car takes a while to move after starting and when it gets warmed up, the clutches tend to slip more. Could this be related to the Bank1 loosing current to all injectors?
I have checked the fuses and wiring as suggested by you but find no fault in them. Please Help.
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

There isn't a relay involved and the ECM isn't what powers the injectors. They all receive power from a fuse. How are you determining that they are losing power?

Ask Your Own Lexus Question
Customer reply replied 2 years ago
We measure the current going to the injectors with a meter. In cold all 8 injectors have current but in hot the left bank shows no current at all while the right bank continues to run. In the fuse box there are 2 separate fuses for the fuel injection system, both have been checked along with the holders, wiring and sockets and are OK. Why does the current disappear when hot is the question.
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

The circuit that powers the injectors is opening. All injectors are powered by the same fuse, a single wire leaves the fuse and it breaks up to go to eight injectors. There has to be an open circuit on the power feed wire.

Ask Your Own Lexus Question
Customer reply replied 2 years ago
If as you say there is an open circuit in the feed wire, how come it works when the engine is started and upto about 3-4 kms drive? Again if you are right, there has to be some connection between the circuit working when cold and getting open when hot.
Also if one fuse is powering all 8 injectors then current to and from the fuse has to be OK or else the other 4 injectors would also not work.
As I had asked earlier, is there a link between the transmission and the injectors to sort of protect the gears from slipping by over revving, it cuts the current to one bank of injectors. Please explore this possibility as well. Thanks very much.
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

No, there is nothing that will shut off injectors to protect the transmission, and if that was the case then all eight would shut off. The injectors are all powered from the same fuse, the same wire leaving it. If some injectors have powre and some don't then you have an open circuit to the ones that don't have power at that time.

Ask Your Own Lexus Question
Customer reply replied 2 years ago
Okay, so I am going to get into the wiring to check for any defects. The fuse in this car is a 20 Amp one that when removed cuts the current to all 8 injectors. I will trace the wiring and get back to you. Tomorrow is a holiday so I will only be able to work on the car again on Friday the 18th. i will keep you posted.
Thanks.
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

You're welcome!

Ask Your Own Lexus Question
Customer reply replied 2 years ago
Hi Don, I have opened the wiring loom from the fuse to the injectors on the left bank and all checks out ok. All the wire insulation is intact and does not show an open circuit anywhere. What should I do now?
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

If only four injectors are losing power there has to be an open circuit to those four. You can hardwire then if your'e unable to find the problem.

Ask Your Own Lexus Question
Customer reply replied 2 years ago
Hi Don, after refitting the wiring we tested the car again. There was no difference. However, when testing the current with a bulb accross the two terminals of the injectors of the working right bank, the bulb flickerers intermittently. On the left bank, in cold start it also flickers but after a short drive it does not. On testing the main current to ground it shows continuous current. This means this means that in failed condition current is coming to the injectors but breaking contact when hot on the other end. Where does this second wire go from the injector? I tried direct earth, it does not work, I tried hot wiring it to the corresponding wire on the right bank, it does not work. What should I try next? Sorry this dragging on for so long but I must get to the bottom of this. I sincerely ***** ***** the help you are giving me.
Regards,
Cyrus.
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

You're actually losing injector pulse rather than power then.

Are any P codes currently setting?

Ask Your Own Lexus Question
Customer reply replied 2 years ago
The fault codes showing are the same.
P0135 & P1349.
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

If you clear the codes does the P1349 reset immediately when you start it? If not, are the injectors only losing pulse when the code sets?

Ask Your Own Lexus Question
Customer reply replied 2 years ago
Most likely it does but I will have to check that out. After resetting codes, P0135 comes on immediately on starting. I interchanged the O2 sensors from left to right. The car ran well for 10 miles (instead of the usual 4) and then again, left bank was not firing. So the O2sensor is not the cause.
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

We need to see if the injector drivers are being shut off as a result of the P1349 setting.

Ask Your Own Lexus Question
Customer reply replied 2 years ago
How do I test the injector drivers & where would they be located. How do I resolve the P1349 issue.
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

Your question thread was about the injectors not working but you don't know if they're actually turning off? Why did you initially believe they were turning off?

Ask Your Own Lexus Question
Customer reply replied 2 years ago
The injectors do turn off after a short run. We tested them with a test lamp accross the terminals of the wires going to the injectors when cold and the lamp lights up and when hot the lamp does not light up. That's why I thought there was a loss of current to the injectors. But after you told me about there being a common suply to all 8 injectors, even when the test light does not come on when hot, the current to the injectors when tested to ground is there. It would therefore seem that only when hot, something is failing. What should i test now and how.
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

Do the injector drivers only turn off when the P1349 is active?

Ask Your Own Lexus Question
Customer reply replied 2 years ago
When code P1349 is reset, the bank 1 injectors begin working but stop again after a short drive.
Stopping the car with ignition off for 5 minutes when they are not working and then on re starting the injectors begin to work again. I removed,
tested and refitted the oil pressure solenoid on bank 1. It is not stuck. When is it supposed to be energised?
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

I'm a full time tech and at work this morning, I'll get back to you as quickly as I can.

Ask Your Own Lexus Question
Lexus Mechanic: sprinkles08, ASE Certified Technician replied 2 years ago

Do you have the VIN?

Ask Your Own Lexus Question
Ask sprinkles08 Your Own Question
sprinkles08
sprinkles08
sprinkles08, ASE Certified Technician
Category: Lexus
Satisfied Customers: 23,258
23,258 Satisfied Customers
Experience: ASE Master and Advanced level certified. Factory trained with 17 years dealership experience

sprinkles08 is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

THANK YOU, THANK YOU, THANK YOU!! I've got my baby back. Tomorrow I will get a tank of high octane, remove the top, go for a long long ride and enjoy my car. THANK YOU!

JugheadUSA

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

lexpert

lexpert

Lexus Master tech

2,100 satisfied customers

Master Certified with lexus, 8 years experience with Lexus

Skyvisions

Skyvisions

ASE Certified Technician

1,759 satisfied customers

Lexus Expert

Ron Z.

Ron Z.

- Lexus Tech -

423 satisfied customers

18+yrs experience. State Inspector and Lexus Diagnostics

Chris (aka - Moose)

Chris (aka - Moose)

Technician

297 satisfied customers

16 years of experience

AMD

AMD

Master Technician

270 satisfied customers

L1 Advanced Level Diagnostics Specialist

George H.

George H.

ASE Certified Technician

217 satisfied customers

15+ years ASE Master w/L1 Drivability certification

Tim Mohr

Tim Mohr

ASE MASTER

125 satisfied customers

30 YEARS EXPERIENCE, FORIEGN AND DOMESTIC, GAS AND DIESEL

< Previous | Next >

Related Lexus Questions
The rear lift gate door will not shut. it is open half way
The rear lift gate door will not shut. it is open half way and will not shut manually, will not shut with the key or with the push button on the lift gate. … read more
Daniel Lee
Daniel Lee
Lead Automotive Technician
Automotive Technology
15 satisfied customers
Check engine light code p1354. On. Lexus es300 2001. Es 300,
check engine light code p1354 JA: Does the light stay on, or does it blink? Customer: on JA: What is the make/model/year of your car? Customer: Lexus es300 2001 JA: Are you fixing your GS300 yourself?… read more
Peter Bagley
Peter Bagley
master technition
Vocational, Technical or Trade School
908 satisfied customers
Having a issue with 2007 Lexus LS460L with air suspension
Having a issue with 2007 Lexus LS460L with air suspension issues. Sending code of C1734 which is:"RL Damping Force control actuator circuit" for Rear Left. Have in Toyota dealer now getting worked on … read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
Died. Put in new battery. Instrument cluster is dark, Car
Hey battery died. Put in new battery. Instrument cluster is dark, Car will not turn over. Checked all fuses and they are fine. Tried resetting by disconnecting negative cable but no use. Car has been … read more
Peter Bagley
Peter Bagley
master technition
Vocational, Technical or Trade School
908 satisfied customers
No fuel getting to the engine, spent 800.00 at local service
no fuel getting to the engine, spent 800.00 at local service shop.replaced fuel pump and pressure regulator.engine did start but ran rough. went pick it up and it wouldn't start. wanted 300.00 more. t… read more
Matt
Matt
Engineer
Bachelor\u0027s Degree
5 satisfied customers
It is running a bit rough, has Check AWD System did Trac Off
It is running a bit rough, has Check AWD System did Trac Off message along with the check engine light … read more
Gunvir Singh
Gunvir Singh
1,705 satisfied customers
I have a 1992 Lexus LS 400. Starting about two years ago,
I have a 1992 Lexus LS 400. Starting about two years ago, the engine would lose power but not die. This happened at a stop light. After a few minutes, the engine was fine, and I ignored the incident a… read more
lexpert
lexpert
Lexus Master tech
Vocational, Technical or Trade Scho
2,100 satisfied customers
I have a 2002 sc430. the gps seems to be functioning
Hi, I have a 2002 sc430. the gps seems to be functioning normally except there is no map data on screen, just the "cursor" … read more
Shawn Few
Shawn Few
AS
63 satisfied customers
Trying to replace the low beam D2S on the driver's side.
trying to replace the low beam D2S on the driver's side. Can't get enough access by removing the fender splash shield and also not enough room through the top even after freeing up the fuse/relay box … read more
Cesar Jimenez
Cesar Jimenez
Vocational, Technical or Trade School
2 satisfied customers
Does the lexus gs430 has an inherit light steering wheel
Does the lexus gs430 has an inherit light steering wheel problem, if so can it be modified or fixed… read more
Matt J
Matt J
Owner of Jones Automotive
Vocational, Technical or Trade Scho
1,000 satisfied customers
Just had Lexus LSwindshield changed by SafeLite and power
just had Lexus LS(###) ###-####windshield changed by SafeLite and power steering is not working - is there any possible relationship … read more
rpmdiag
rpmdiag
High school
7,114 satisfied customers
My VCS trac and Trac off along w check engine light came on.
My VCS trac and Trac off along w check engine light came on … read more
Ron Z.
Ron Z.
- Lexus Tech -
Vocational, Technical or Trade Scho
423 satisfied customers
My 1998 ls 400 has a vibration problem when In park at
my 1998 ls 400 has a vibration problem when In park at different rpms whats with that? … read more
Toyota Service
Toyota Service
Toyota Dealership Service & CR Manager
1,344 satisfied customers
HOW MANY CATALYTIC CONVERTERS ARE THERE IN LEXUS RX350 (YEAR
HOW MANY CATALYTIC CONVERTERS ARE THERE IN LEXUS RX350 (YEAR 2007) .THE COMPUTER READINGS INDICATED 420 & 430 ( BANK 1 AND BANK 2)THE MECHANIC SAID, THE CC ARE BAD AND NEED TO BE REPLACED. IS THIS TRU… read more
George H.
George H.
ASE Certified Technician
Associate Degree
217 satisfied customers
I recently replaced my brake rotors and pads on my car –
Hi, I recently replaced my brake rotors and pads on my car – brand new oem 14” Lexus rotors and pads. But shortly after a brake vibration came back. It is mainly at lower speeds less than 45mph when s… read more
Jared D
Jared D
Shop Supervisor
Bachelor\u0027s
3 satisfied customers
Lexus 2002 300RX Code:: Active Engine Code P0330 / Knock
Lexus 2002 300RX Code:: Active Engine Code P0330 / Knock Sensor 1 Circuit Bank 2...Thoughts… read more
Michael Solis
Michael Solis
252 satisfied customers
Ls430 code 2056 pcs axel gap... Pre collision system fault.
ls430 code 2056 pcs axel gap... Pre collision system fault. extracted above code, hard code, won't reset, something about axel gap and sensor... where are these sensors?… read more
LexusPro
LexusPro
Master Lexus Technician
1,031 satisfied customers
I have a 1998 Lexus. Ls400 with 136000 miles. Can a mechanic
ls400 with 136000 miles. Can a mechanic tell if the timing belt has been changed? … read more
Ron Z.
Ron Z.
- Lexus Tech -
Vocational, Technical or Trade Scho
423 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x