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 RussMasterTech Your Own Question

RussMasterTech
RussMasterTech, ASE Certified Technician
Category: Car
Satisfied Customers: 791
Experience:  19 years of GM Dealership experience. ASE Master with L1 and GM Master Certified.
Type Your Car Question Here...
RussMasterTech is online now
A new question is answered every 9 seconds

1996 Pontiac Sunfire 2.4L. I have a code of p0300 multi-misfiring.

Customer Question

I have a 1996 Pontiac Sunfire 2.4L. I have a code of p0300 multi-misfiring. I have replaced the ignition module, ignition coils, coil tower, wires, plugs, crank sensor, knock sensor, pcm. When I replaced the ICM all four cylinder started to work for 1 minute and started to misfire again. The first misfiring was from cylinder 1 & 4. The second misfiring came from cylinder 2 & 3. Can you please advice me on to how to approach this issue. Thank You
Submitted: 6 years ago.
Category: Car
Expert:  RussMasterTech replied 6 years ago.

Hello.

When does your engine misfire?

Customer: replied 6 years ago.
It misfires as soon as I start the car. The check engine light flashes and the cooling fan comes on. The cataltic converter becomes red. I checked all the injectors and it shoots gas they all work correctly.
Expert:  RussMasterTech replied 6 years ago.

I had one of these cars with the 2.4 engine where the timing chain had jumped a tooth, or the chain had become so worn that the cams were no longer timed correctly. Since the miss is on all cylinders, you should try checking the cam timing marks to make sure they haven't jumped. I've also seen it where the oil pump pressure regulator valve sticks and the oil pressure goes sky-high. Sometimes it can go as high as 90 psi. This will do a couple of things. The oil filter may baloon up, and or the lifters will over pump and hold the valves open thus creating a misfire condition. You might be able to verify the timing chain condition with a compression test. The oil pump issue, you'll need to hook an oil pressure gage into the port where the oil pressure switch is located. This is by the power steering pump on the intake cam housing.

Good luck. Let me know how it turns out.

 

Thanks for using Just Answer.

Russ

RussMasterTech, ASE Certified Technician
Category: Car
Satisfied Customers: 791
Experience: 19 years of GM Dealership experience. ASE Master with L1 and GM Master Certified.
RussMasterTech and 9 other Car Specialists are ready to help you
Customer: replied 6 years ago.
I took the ignition coil pack and module out of the spark plugs to see if I get sparks to each cyindar.(Like removing the spark plug wires from the plugs and holding it close to the ground and cranking the engine to see if I have a spark) but I set it on top of the engine and I saw 1 an 4 did not spark but 2 and 3 did spark and I have good compression on all cyindars. (I played with the crank pully and I haveno free movement, I don't think the timming chain is loose).
Expert:  RussMasterTech replied 6 years ago.

If one set of cylinders is not firing, then the coil that runs that cylinder or the module that runs the coil is at fault. It could also be the wiring harness between the module and the coils. I know I see that you've replace the coils and the module and the housing, but maybe try swapping the coils and see if the no spark condition stays on 1 and 4 or moves to 2 an 3.

 

Thanks for using Just Answer.

Russ

Customer: replied 6 years ago.
ok, I'll follow your advice I will get back to you tomorrow. (I was thinking it could be the wiring harness) Thanks
Expert:  RussMasterTech replied 6 years ago.

Let me know how it works out, but if I've been of any help already, please make sure to click the "Accept" button so I may receive credit for helping you. I'll be glad to help you in the future.

Thanks again,

Russ

Customer: replied 6 years ago.
Hi Russ, thank you for your help the car is now runming
Expert:  RussMasterTech replied 6 years ago.

That's great!!!

Glad I could help.

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 P Elm City, NC
< Last | Next >
  • 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
  • Excellent reply, and also very quick. Really sounds like the Expert knows what he is talking about. I will be back to use your service when I need more help with my RV. Dutch USA
 
 
 

Meet The Experts:

 
 
 
  • Chris (aka-Moose)

    Technician

    Satisfied Customers:

    846
    16 years of experience
< Last | Next >
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris (aka-Moose)'s Avatar

    Chris (aka-Moose)

    Technician

    Satisfied Customers:

    846
    16 years of experience
  • http://ww2.justanswer.com/uploads/TE/TedG/2012-6-15_14759_avaLarge.64x64.jpg Ted G.'s Avatar

    Ted G.

    ASE Certified Technician

    Satisfied Customers:

    1596
    20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness
  • http://ww2.justanswer.com/uploads/joecamel90/2008-11-13_03615_head_shot.jpg George H.'s Avatar

    George H.

    ASE Certified Technician

    Satisfied Customers:

    1311
    ASE Master Tech 15+ yrs, AAS Automotive Technology, Factory trained Asian specialist
  • http://ww2.justanswer.com/uploads/AM/amedee/2013-10-24_23656_Amedee1.64x64.jpg Amedee's Avatar

    Amedee

    ASE Master Tech

    Satisfied Customers:

    2367
    ASE Master Tech advanced level specialist
  • http://ww2.justanswer.com/uploads/SU/supermechanic/2013-8-23_03546_500.64x64.jpg Jerry's Avatar

    Jerry

    Master Mechanic

    Satisfied Customers:

    1906
    ASE master, 30+ years. All makes and models. Trouble shooter, shop forman, service manager
  • http://ww2.justanswer.com/uploads/CR/crzydrvr00/2013-11-3_12123_246347.64x64.jpg Richard's Avatar

    Richard

    ASE Certified Technician

    Satisfied Customers:

    942
    12 years Ford Lincoln/Mercury Jaguar dealership as a technician and shop foreman reparing all makes
  • http://ww2.justanswer.com/uploads/ST/Steve7654/2012-6-5_215929_japic800x660.64x64.jpg Steve's Avatar

    Steve

    Auto Service Technician

    Satisfied Customers:

    1980
    25+ yrs experience as a professional working technician; ASE L1 master technician