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Eric
Eric, Automotive Repair Shop Manager
Category: Honda
Satisfied Customers: 29979
Experience:  20+ yrs. experience as repair shop manager and technician.
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I have a 2000 Honda Accord 3.0 V6. I have a check engine

Customer Question

I have a 2000 Honda Accord 3.0 V6. I have a check engine light on and a misfire. The misfire is on every cylinder. The codes that come up are p0300, p0301, p0302, p0303, p0304, p0305, p0306, p1399. I have replaced the EGR valve and the fuel pressure regulator. Coils are all good and the spark plugs were just changed. I can't get it to stop misfiring. Please help.
Submitted: 11 months ago.
Category: Honda
Expert:  Eric replied 11 months ago.

HI,

Most commonly misfires on all cylinders is due to valves being out of adjustment on this engine, especially if more than 60K miles since they were last adjusted. You need to start with adjusting the valves on the engine to correct this. This is a very, very common cause

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Customer: replied 11 months ago.
how do i adjust the valves?
Customer: replied 11 months ago.
is it possible that its a fuel problem?
Expert:  Eric replied 11 months ago.

HI,

Ok, I have uploaded the valve adjustment procedure for you as a pdf file attachment.

Well, I assumed you checked the fuel pressure before replace the fuel pressure regulator. But if you didnt, then you do need to check pressure as weak pressure can cause this. Pressure should be 40-48psi with vacuum line disconnected to the regulator with engine idling

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Customer: replied 11 months ago.
does the car have a valve to check the fuel pressure?
Expert:  Eric replied 11 months ago.

HI,

No it doesnt. I have attached how to connect and test fuel pressure

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Customer: replied 11 months ago.
now if the fuel pressure it out of spec and too low. what parts should i look at?
Expert:  Eric replied 11 months ago.

HI,

If too low, then you will need to replace the fuel pump located in the fuel tank - it is accessed thru the trunk. Directions are attached. The fuel filter is part of the fuel pump assembly, so replace the whole assembly

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Expert:  Eric replied 11 months ago.

I noticed we have not yet resolved your concern you asked about. I would sure appreciate it if you would reply so I can offer my skills and knowledge and repair guide access to help as best I can.

~Do you still need more help?
~Confused by my info request or answer?
~Need more time?
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If the answer is YES to any of these just press reply and lets work on this concern some more.

If you have new questions now or in the future please do not hesitate to ask them. If you would like me to assist you. Just bookmark this page so you can access my profile easy and post a new question from the question box on my profile page. Please remember to rate service using the rating page so that I may receive credit. Thanks

Customer: replied 11 months ago.
Hello. Sorry for the long delay. I couldn't find a kit with the right attachment to test fuel pressure so I'm just going to replace the fuel pump and filter. The parts come on Thursday so I will message you back with the results on Thursday or Friday.
Expert:  Eric replied 11 months ago.

HI,

Ok, sounds good

Customer: replied 11 months ago.
Hello. So I changed the fuel pump and filter and strainer and it didn't make a difference. Should I be leaning towards that it's the valve lash?
Expert:  Eric replied 11 months ago.

HI,

Yes, as I stated in my original answer, valves out of adjustment is the most common cause of misfires on all cylinders.

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Customer: replied 11 months ago.
Ok now let's say I adjust the valves and it's still misfiring. Then what could the possibility be.
Expert:  Eric replied 11 months ago.

Hi,

Base engine timing could be off, the ecm could be faulty or a wiring issue. The odds of those are low. Again, the MOST common cause on this engine is valves being out of adjustment.

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Expert:  Eric replied 11 months ago.

I noticed we have not yet resolved your concern you asked about. I would sure appreciate it if you would reply so I can offer my skills and knowledge and repair guide access to help as best I can.

~Do you still need more help?
~Confused by my info request or answer?
~Need more time?
~Confused on how the site works?
~Need more detail or a different explanation?

If the answer is YES to any of these just press reply and lets work on this concern some more.

If you have new questions now or in the future please do not hesitate to ask them. If you would like me to assist you. Just bookmark this page so you can access my profile easy and post a new question from the question box on my profile page. Please remember to rate service using the rating page so that I may receive credit. Thanks

Expert:  Eric replied 11 months ago.

I noticed we have not yet resolved your concern you asked about. I would sure appreciate it if you would reply so I can offer my skills and knowledge and repair guide access to help as best I can.

~Do you still need more help?
~Confused by my info request or answer?
~Need more time?
~Confused on how the site works?
~Need more detail or a different explanation?

If the answer is YES to any of these just press reply and lets work on this concern some more.

If you have new questions now or in the future please do not hesitate to ask them. If you would like me to assist you. Just bookmark this page so you can access my profile easy and post a new question from the question box on my profile page. Please remember to rate service using the rating page so that I may receive credit. Thanks