Mercedes

Have Mercedes questions? Ask a mechanic for answers ASAP

Ask an Expert,
Get an Answer ASAP!

Random misfire from 1 2 3 and 4 changed all spark plugs and…

Customer Question
Random misfire from 1...

Random misfire from 1 2 3 and 4 changed all spark plugs and coils still same codes no injector pulse from those cylinders

Mechanic's Assistant: Have you seen the misfire code before? Has the car been stalling?

No and no

Mechanic's Assistant: What is the model/year of your Mercedes?

2008 ml 350

Mechanic's Assistant: Are you fixing your vehicle yourself? What have you tried so far?

Yes changed all spark plugs and coils and crank sensors

Submitted: 3 months ago.Category: Mercedes
Show More
Show Less
Ask Your Own Mercedes Question
Answered in 24 minutes by:
3/30/2018
Mercedes Mechanic: David Craig, Auto Mechanic replied 3 months ago
David Craig
David Craig, Auto Mechanic
Category: Mercedes
Satisfied Customers: 5,808
Experience: Owner/Mechanic at 3D Automotive
Verified

Hi my name is ***** ***** I'll be more than happy to assist you, Please allow me a few minutes to review your information. Thank you.

Ask Your Own Mercedes Question
Mercedes Mechanic: David Craig, Auto Mechanic replied 3 months ago

since you are not getting injector pulse on those cylinders you need to do a continuity test of the wiring form those injectors to the computer

Ask Your Own Mercedes Question
Mercedes Mechanic: David Craig, Auto Mechanic replied 3 months ago

diagram

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
where does the power supply come from for the injector
Customer reply replied 3 months ago
hello?
Mercedes Mechanic: David Craig, Auto Mechanic replied 3 months ago

im busy with other customers so a little patience is appreciated

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
didn't realize you are working with other customers thought this was one on one personal service (1st time using it) so I understand now and will be patientwhich color is the power wire for the injector?
Mercedes Mechanic: David Craig, Auto Mechanic replied 3 months ago

please standby. thanks

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
the pulse to the ground is 3.2
Mercedes Mechanic: David Craig, Auto Mechanic replied 3 months ago

you need to use a noid light to check for pulse

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
1st start get pluse for 30 seconds then no pulse
Mercedes Mechanic: David Craig, Auto Mechanic replied 3 months ago

and what are all of the fault codes?

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
p0300, p0301, p0303, p0304
Mercedes Mechanic: David Craig, Auto Mechanic replied 3 months ago

im not sure on this one if you are losing pulse after 30 seconds. I would suspect the computer, but I will open this up to the others.

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
ok thank you, ***** ***** on the response time from the new mechanic?
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago
Wolfgang
Wolfgang, Mercedes Technician
Category: Mercedes
Satisfied Customers: 5,219
Experience: master tech benz ase cerified L1 and L2
Verified

Welcome, I'm Wolfgang, Master Benz Tech.

  • WORK TIME, I am here 7 days a week but not all hours of the day, do not worry I will respond.
  • FEES, I am a user of the website like you, not an employee. Any fee or account questions need to be addressed to the website.
  • PHONE CALLS are automatically offered by the website. I or another may take the call if you request one.
  • UPLOADED LINKS, if I upload dropbox links, without the phone app use the box on the top right for direct download.
  • RATING ANSWERS, please let me know what you need from me so you are pleased with my answer.

I do need the vin # to get the factory information to assist.

Thanks

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
vin # 4JGBB86E08A299656
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago

ok what I need you to do is to have the key on engine off and measure on all 6 injectors disconnected pin 1 to ground what is the voltage reading?

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
cant disconnect all the injectors need to remove the harness I did disconnect #3 and 1
Customer reply replied 3 months ago
is the intake hall injector part of the injector pulse?
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago

the 4 cam shaft magnets and all 6 injectors share the same power. so what is the voltage measurement on pin on of injector 1 and 3 to ground please.

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
3.2
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago

ok disconnect one of the cam magnet and measure pin 2 to ground

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
injector power is good no problem - the injector is missing the ground pulse what supplies the ground pulse?
Customer reply replied 3 months ago
sorry i'm not sure what you mean when you say "measure pin 2 to ground"
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago

ok now you are giving me 2 different answers.

i have asked you first what is the voltage measurement of pin 1 of the injector you can get access to ground and you said 3.2v

then you come back that the power to the injector is good . good means 12v. so this tells me that you have both which cannot be .

please understand I'm trying to help but giving implausible values of the same circuit will not get anywhere!!

ground is the ground stud on the passenger side on the fender area.

so again i need you to disconnect injector plugs you can gain access and then measure from pin 1 to ground with the key on engine off.

Ask Your Own Mercedes Question
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago

on the connector housing there is numbers of what is pin 1 and 2.

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
the 3.2 is from the ground wire from the injector - the injector is getting power always key off key on car running still getting power 12 volt
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago

ok that sounds better. 3.2 v sounds right you have to remember you are dealing with transistors (drivers) that run the injectors.

let me ask you this before any repairs of the misfire issue any recent work , accidents, any mice nests?

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
no mice nest - accident 3 yrs ago
Customer reply replied 3 months ago
right front wheel
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago

did you do a compression check on all cylinders?

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
no problems
Customer reply replied 3 months ago
car starts first key but shaking
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago

what you mean no problems? I like actual values to eliminate mechanical issue . what was the pressures in all 6 cylinders?

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
150 psi
Customer reply replied 3 months ago
can you tell me what supplies the ground signal to the injector, please
Customer reply replied 3 months ago
does it come from the computer only?
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago

yes from ecu .

Ask Your Own Mercedes Question
Customer reply replied 3 months ago
the white and red wire on the #3 injectors what is the signal suppose to be
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago

when running toggle to ground

Ask Your Own Mercedes Question
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 3 months ago

heading to sleep we can pick this up in the morning is that ok?

Ask Your Own Mercedes Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a mercedes mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Wolfgang Your Own Question
Wolfgang
Wolfgang
Wolfgang, Mercedes Technician
Category: Mercedes
Satisfied Customers: 5,219
5,219 Satisfied Customers
Experience: master tech benz ase cerified L1 and L2

Wolfgang 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:

I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry.

Stephanie PElm City, NC

used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future.

David L.Richmond, TX

9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much.

PhilMarysville, CA

Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible.

CharlesWalnut Creek, CA

As a single woman, I really appreciate an excellent and affordable opinion.
Thank you Geordie, I will not hesitate to contact justanswer in the future!

SueCharleston, WV

Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff.

JimCastleberry, FL

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

< Previous | Next >

Meet the Experts:

MB Paul

MB Paul

Mercedes Technician

3,567 satisfied customers

Qualified Mercedes Benz Diagnostic Technician - 20+ years experience - Workshop Foreman for Mercedes

Marty

Marty

Mercedes Technician

29,460 satisfied customers

Bosch Certified Master Tech. Over 35 years experience.

Lou P. master tech

Lou P. master tech

Mercedes Technician

4,460 satisfied customers

20 years Master Certified excellent fix rate and have access to factory wiring, and instructions.

Michael Warfield

Michael Warfield

Factory Mercedes-Benz Technician

3,132 satisfied customers

Mercedes-Benz Master Certified technician

Matt

Matt

Engineer

643 satisfied customers

Mechanical Engineer with 23 years experience in the auto industry, 8 yrs in formula 1 engine testing

promerc

promerc

mercedes diagnostic technician

553 satisfied customers

Qualified mercedes diagnostic technician & service team manager , ATA registered Master tech

Hipo64

Hipo64

Mercedes Technician

444 satisfied customers

Work and diagnose electronics on daily basis.

< Previous | Next >

Related Mercedes Questions
I have misfire on cylinder 3 and 4, I changed the 2 coils
I have misfire on cylinder 3 and 4, I changed the 2 coils and the 8 spark plugs and I still have the same error code … read more
Gunvir Singh
Gunvir Singh
1,949 satisfied customers
Has code P0300 and P0304. replaced spark plug and coil,
has code P0300 and P0304. replaced spark plug and coil, still has misfire. has spark to plug … read more
Marty
Marty
Mercedes Technician
Associate Degree
29,460 satisfied customers
2005 c230 died while driving the other day and wouldn't
2005 c230 died while driving the other day and wouldn't start. Threw codes p0300, p0303, p0304. It ran rough a few months ago and threw code p0301 so I replaced the plugs and replaced the ignition coi… read more
Dan
Dan
Dealership Technician
Associate Degree
2,108 satisfied customers
97 mercedes c280 won't start put in new crankshaft sensor
97 mercedes c280 won't start put in new crankshaft sensor plugs and wires still just turn over… read more
XtraTech
XtraTech
Sr. Technician
Bachelor's Degree
149 satisfied customers
ML320: How do I repair codes P0300, P304, P0305 and P0306 of
How do I repair codes P0300, P304, P0305 and P0306 of ML 320 with V6 3.2L. Spark plugs and spark plug wires are already replaced. I also switch ignition coil from cylinder 1 to cylinder 4, cleared cod… read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
Bachelor's Degree
4,460 satisfied customers
ML350: Hi Marty I have a Mercedes Benz ML350 2009 with vin
Hi Marty I have a Mercedes Benz ML350 2009 with vin WDC1641862A546470. The problem is the engine light is on and the car is missing. I have changed all the spark plugs but the problem is the same. The… read more
Marty
Marty
Mercedes Technician
Associate Degree
29,460 satisfied customers
cl600: I have 2002 Mercedes Benz cl600. My wife filled it
I have 2002 Mercedes Benz cl600. My wife filled it with lower octane gas and it caused multiple misfire about 8 all scattered. I found out and drained the gas and out the right gas in and after half a… read more
Marty
Marty
Mercedes Technician
Associate Degree
29,460 satisfied customers
ML350: p2050 misfiringp2053 misfiringp2043 misfiringp2046
p2050 misfiring p2053 misfiring p2043 misfiring p2046 misfiring - What is the reason for p2050 & p2053 continuous misfiring with continuous check enline light coming on?… read more
Hipo64
Hipo64
Mercedes Technician
High School or GED
444 satisfied customers
ml500: hi I just rebuild engine on 03 ml 500, new rings gaskets
hi I just rebuild engine on 03 ml 500, new rings gaskets etc (engine lost valve seats on couple cylinders got new block with pistons, donor heads from s500) my issue bank 2 has misfire on all cylinder… read more
Hipo64
Hipo64
Mercedes Technician
High School or GED
444 satisfied customers
2006 C230: w/2.5, cyl..misfiring..disconnect..fuel injector i
i have a 2006 C230 w/2.5, cyl's 4 and 6 are misfiring with codes 0307 (po204) and 0315 (p0206).while the car is running and i disconnect the fuel injector i have no noid light but if i shut it off and… read more
Marty
Marty
Mercedes Technician
Associate Degree
29,460 satisfied customers
1999 E320 4matic: prob..about 67 mph..most I could rev was 2500 rpm.
Hi there I have a prob with my 1999 E320 4matic. I was driving last week at about 67 mph and I felt a jolt then I noticed I had no power. The most I could rev was 2500 rpm. I stopped and scanned the c… read more
MB Paul
MB Paul
Mercedes Technician
Vocational, Technical or Trade Scho
3,567 satisfied customers
Mercedes-Benz ML430: I Have a 99 ML430, I have misfire code
I Have a 99 ML430, I have misfire code in 4 cylinders. I changed the spark plugs, ignition wires and fuel filter. Keeps doing the same thing. I checked the injectors pulse and its good for a few minut… read more
Marty
Marty
Mercedes Technician
Associate Degree
29,460 satisfied customers
E320: 1999 mbz..oil changes..diagnostic..Cylinders..spark plugs
I have a 1999 MBZ E320 with 170,000 miles on it. I have kept up with the oil changes and regular maintenance myself, having been a Mechanic at one time. Last month, the car suddenly went into "limp" m… read more
Stan
Stan
Technical support engineer
Bachelor\u0027s Degree
106 satisfied customers
2003 c240: cylinder..injectors..spark plugs and the coils
2003 c240 4matic When the car heats up (30 seconds to 2 minutes) it starts running rough, missing on cylinder 2. I have a code reader and it seems to be #2 all the time. I had the injectors flushed, n… read more
Stan
Stan
Technical support engineer
Bachelor\u0027s Degree
106 satisfied customers
96 E320: LEAKING..MISFIRE..SPARK PLUGS, ANTIFREEZE WAS..BOTH CYLINDER
MY NAME KEVIN I OPERATE AN AUTO REPAIR SHOP, A CUSTOMAS 96 E320 IN THE SHOP FOR AN OVER HEATING PLOBLEM. THE WATER PUMP WAS LEAKING FROM THE WEEP HOLE,SO REPLACE THE WP AFTER DOING THE WATER PUMP I TO… read more
Marty
Marty
Mercedes Technician
Associate Degree
29,460 satisfied customers
slk320: replaced mass air flow sensor..runs fine..rev..swapped coils
I have a 01 slk320. Had codes p0306 and p0300, replaced mass air flow sensor, no help.Car runs fine at idle, but when almost hits rev limiter starts skipping and cutting back.Fuel pressure holds,chang… read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
Bachelor's Degree
4,460 satisfied customers
2005 Mercedes E320: Crankshaft sensor..random cylinder misfire
Good Evening, 2005 Mercedes E320 4 Matic Crankshaft sensor code,random cylinder misfire, cylinder 2 misfire,cylinder 4 misfire,cylinder 6 misfire .changed crank sensor cleared codes, misfires return s… read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
Bachelor's Degree
4,460 satisfied customers
2000 E320 4Matic: After warm-up, under load..missfire..Restarting
2000 E320 4Matic. After warm-up, under load it develops a missfire. Restarting engine corrects it until next hard acceleration. Injector signal goes away on 2 or 3 cylinders but never the same ones. A… read more
Nelson Garcia
Nelson Garcia
Vocational, Technical or Trade Scho
1,092 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