How JustAnswer Works:

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

Ask Jay Your Own Question

Jay
Jay, Nissan Technician
Category: Nissan
Satisfied Customers: 15066
Experience:  20+yrs experience with Nissan & Infiniti Trained & Certified.Currently still working for Dealer
10181755
Type Your Nissan Question Here...
Jay is online now
A new question is answered every 9 seconds

Rough idle, check engine light (random misfire..smooth..accelerator

Resolved Question:

Rough idle, check engine light (random misfire, knock sensor). Idles rough (rpms drop) and every few seconds rpms will go back up and it will idle smooth, then goes back to idling rough. While driving it will drive fine then Ill feel a loss of power and have to peg the accelerator to speed up. The CEL will start flashing. Recently it has also started lurching while im driving sometimes. All of these issues come and go during an average trip around town. Ive replaced the entire distributor, spark plugs, wires, fuel filter, and cleaned the MAF sensor. Does this sound familiar to anyone?
Submitted: 2 years ago.
Category: Nissan
Expert:  Jay replied 2 years ago.

Jay :

Hello and thank you for using JustAnswer.com

Jay :

Do you have a Service Engine Soon light on?

Customer:

It comes and goes.

Jay :

Do you know what code you have when the light is on?

Customer:

Knock sensor, random multiple cylinder misfire

Jay :

What brand spark plugs do you have in the engine? Do you know?

Customer:

I just replaced them with the autolites from autozone. The same fault exists before and after replacing them.

Jay :

First thing I would recommend is using Factory NGKs

Jay :

Every time I ever see misfire codes it's due to other brand spark plugs

Jay :

These engines don't like other brand spark plugs

Jay :

So the first thing I would start with is putting NGK spark plugs in this engine

Jay :

Then run it and see how it is.

Jay :

Now the distributor you replaced, you got that from your local auto parts store also?

Jay :

Do you have access to a scanner, not a code reader?

Customer:

Yes I did. I understand it's not recommended, however the exact same condition existed before and after replacing it, so logic says that it was never the cause. The bearing in the original distributor was shot (had rusty metal shavings all around it).

Customer:

I dont have direct access to a scanner.

Jay :

Well this is not going to be one magic answer. It's going to take a few tests

Jay :

The first thing I would start with is the plugs, make sure they are NGKs

Jay :

Then, I don't like after market electrical parts, but I am wondering if what your seeing is the fuel trim lean out, then the computer correct it and then it lean out again.

Jay :

I would like to have the fuel trim checked and monitored

Jay :

That will help tell me what is going on.

Customer:

When the car idles in park, it is fine because the RPMs are higher. When i put the car in drive, and the car is warm, the rpms drop and it begins to shake rather bad. Occasionally (maybe once every minute or two) it will correct itself and the idle will go back up and it will be fine, then 30 seconds later return to shaking

Jay :

If the fuel trim can't be controlled, it's possible the problem is the MAF sensor is not able to meter air properly

Jay :

Most of the time MAF sensors they don't completely fail, they fall out of spec. So they meter air, but don't meter air properly

Customer:

I considered the MAF sensor today, but after researching the symptoms it just didnt match up. Is there an inexpensive way to test it?

Jay :

So you can get lean or rich conditions due to the MAF sensor not metering air properly

Jay :

With a scanner, and you have to watch it for a about a second after you unplug it when the truck is running to see if it drops to default before it stalls

Jay :

Also, if you do have a Bad Maf

Jay :

Don't and I mean Don't

Jay :

Replace it with after market

Jay :

They never work!

Customer:

Would i be better off with a junk-yard one?

Jay :

They cause 02 sensors to flat line and cause more running conditions which will have you replace more parts that you don't need to

Jay :

You have to watch Junk Yard ones

Jay :

you don't know how they have been handled

Jay :

If you drop a MAF sensor once

Jay :

It can cause it to fail

Jay :

I don't like using Junk Yard electrical parts,

Jay :

I would use a distributor before a MAF sensor

Customer:

I will replace the spark plugs and troubleshoot the MAF. The other causes I saw during my research was a leak in the intake manifold. Does this sound possible?

Jay :

Intake manifold normally if they leak, it's in the back and it's a little coolant that it leaks.

Jay :

It's never really a vacuum leak if that is what your saying

Customer:

Ok, well you are the first person to suggest the MAF, which is promising. Ive been thinking since day one that it was a sensor or something, because of the way the computer obviously tries to correct the condition.

Customer:

The valve cover gaskets were replaced recently (a few months before this started)

Customer:

And the engine has been run low on oil in the past. I feared compression problems but the way the problem comes and goes had me wondering

Jay :

Oh

Jay :

Wait a min

Jay :

I want you to check something

Jay :

You mentioned you had valve covers done

Jay :

There is one thing I have seen I would like you to check for me

Jay :

I have seen where 02 sensors on the passenger side can get plugged in backwards

Jay :

I want you to go to the 02 sensors on the passenger side.

Jay :

and If you can do this for me it would help me to help you.

Jay :

what I need you to do is this

Jay :

bank 1 is the passenger side, and bank 2 is the drivers side

Jay :

I want you to look at the wire colors for Bank 1 sensor 1 02 sensor, and Ban 2 sensor 1 02 sensor and give me the wire colors on the harness side of the connector

Jay :

So I can check to make sure they are plugged in correctly

Jay :

Then I want you to do the same thing for the rear 02 sensors.

Jay :

Cause if backwards that can also confuse the computer

Customer:

Are the 1 o2 sensors the ones I see plugged into the exaust manifolds?

Jay :

Yes, there is one in the manifold and after the manifold

Jay :

there is two 02 sensors on each side

Jay :

This can also cause the possible misfire if what I am thinking maybe your problem.

Jay :

But you should still put the NGK plugs in the truck

Jay :

:)

Customer:

I will go look right now... standby

Jay :

Take your time

Jay :

I am online till 10 or 11 pm tonght EST

Customer:

Gotcha, thanks for your help so far. I hope you're onto something

Jay :

Lets see if my gutt instinct is right on this.

Customer:

You sir, are a genius.

Jay :

you found something?

Customer:

When I looked at the connectors, I noticed there was a white paint marker drawn across the male and female connectors, but the marks didnt line up. I switched the two connectors, and they matched up perfectly.

Customer:

The car idles smooth now :)

Jay :

Cool deal

Jay :

As soon as you said you did valve covers, that thought came into my head

Jay :

That is why knowing all the information is important

Customer:

That was the kind of thing only a nissan guy would know, anyone else would have just started listed off stuff to replace

Jay :

I know nothing about Nissans...

Jay :

hehe

Jay :

J/K

Customer:

haha

Customer:

Thanks a million for your help Jay

Customer:

you're a pro

Jay :

Your welcome and thank you for using JustAnswer.com

Jay :

Thanks Jay!

Customer:

I still have the CEL engine light on, but im sure its because of the knock sensor which I read isnt a real concern. Im looking for the sell the car soon anyway

Customer:

Thanks again. Take care! :)

Jay :

To clear the SES light

Jay :

Just disconnect the Negative battery terminal for 10 mins

Customer:

Will do.

Jay :

The Misfire can cause the knock sensor code

Jay :

So since we have it all straight now, lets clear all the codes

Jay :

and I am sure you will be fine from this point on..

Jay :

But still get rid of those autolites

Jay :

hehe

Customer:

haha

Customer:

Yes sir

Customer:

If I have any more issues can I send my question to you directly?

Jay :

Yes you can

Jay :

Let me give you a link so you can book mark it

Jay :

1 sec

Jay :

I am normally online in the evenings around 6 pm till 10 or 11 pm EST

Jay :

So that is when you can find me if you ever have any more questions you need help with.

Jay :

Thanks Jay!

Customer:

Awsome

Customer:

Thanks again :)

Jay :

You got it

Jay :

Have a good evening

Jay :

and thank you for using JustAnswer.com

Jay :

Thanks Jay!

Customer:

You too. Feed your gut well for its instincts

Jay :

You like that line.. hehe

Jay, Nissan Technician
Category: Nissan
Satisfied Customers: 15066
Experience: 20+yrs experience with Nissan & Infiniti Trained & Certified.Currently still working for Dealer
Jay and 4 other Nissan Specialists are ready to help you

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 was in trouble with an electrical issue with my brand new Nissan. I frantically went online trying to find help and luckily I found your site. I reached a NISSAN tech named RIP. He was absolutely tremendous and helped me work through the issue. What a pro! cjaz Lexington, KY
< Last | Next >
  • I was in trouble with an electrical issue with my brand new Nissan. I frantically went online trying to find help and luckily I found your site. I reached a NISSAN tech named RIP. He was absolutely tremendous and helped me work through the issue. What a pro! cjaz Lexington, KY
  • 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 P Elm 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. Phil Marysville, 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. Charles Walnut 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!
    Sue Charleston, 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. Jim Castleberry, FL
 
 
 

Meet The Experts:

 
 
 
  • Tim Mohr

    ASE MASTER TECH

    Satisfied Customers:

    446
    30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL
< Last | Next >
  • http://ww2.justanswer.com/uploads/tsmodie/2009-6-10_144056_tim.jpg Tim Mohr's Avatar

    Tim Mohr

    ASE MASTER TECH

    Satisfied Customers:

    446
    30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL
  • http://ww2.justanswer.com/uploads/CA/caprio23/2011-12-13_155550_20111213105344.64x64.jpg Anthony's Avatar

    Anthony

    ASE Certified Technician

    Satisfied Customers:

    306
    ASE Master Automobile Technician with over 18 years exp. in this field.
  • http://ww2.justanswer.com/uploads/FO/fordguy4u/2011-12-17_222940_HPIM1257.64x64.JPG Ron's Avatar

    Ron

    ASE Certified Technician

    Satisfied Customers:

    171
    34 years of automotive Repair
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris(aka-Moose)'s Avatar

    Chris(aka-Moose)

    Nissan Technician

    Satisfied Customers:

    165
    16 years of experience
  • http://ww2.justanswer.com/uploads/EU/eurotec/2012-6-11_13153_mpjaphoto.64x64.JPG Marty's Avatar

    Marty

    ASE Certified Technician

    Satisfied Customers:

    127
    ASE & Bosch master tech. 30 years experience.
  • http://ww2.justanswer.com/uploads/BA/baddad1/2013-8-30_131413_11848761610058140852271553042976n.64x64.jpg Mike V.'s Avatar

    Mike V.

    Nissan Technician

    Satisfied Customers:

    7443
    Nissan factory trained and Certified Subaru Technician.
  • http://ww2.justanswer.com/uploads/CR/crzydrvr00/2013-11-3_12123_246347.64x64.jpg Richard's Avatar

    Richard

    ASE Certified Technician

    Satisfied Customers:

    92
    Nissan Tech ASE certified technician
 
 
 
Chat Now With A Nissan Mechanic
Jay
Jay
Shop Forman / Lead Tech / Parent
12532 Satisfied Customers
20+yrs experience with Nissan & Infiniti Trained & Certified.Currently still working for Dealer