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I have a 99 Accord with 210K miles on it. It idles fine, always starts well but when accelerating it misfires until you either reach about 2800 rpm or you let off on the gas petal and then slowly reapply the gas. If you are cruising along and the engine starts to lug down do to a hill, the engine then starts to misfire again until you again either reach 2800 rpm or you let off the gas. I have checked the EGR passage and it is all clean. Other than the misfire, apparently when the engine is at low vacuum the engine runs fine. Any ideas?
Country: United StatesMake: HondaModel: Accord LXYear: 1999Engine: 4 cyl Already Tried: removed the inlet plenum and found the exhaust passage clean, removed the EGR valve and found good exhaust flow to it. Only trouble codes are cylinder misfire. It has also gotten new plugs.
Hi,The number one cause of cylinder misfire in this engine is valves out of adjustment. They should be adjusted every 90,000 miles and doing so will have the engine running as if brand new. And not difficult to do yourself. Below in pdf file format are directions:CLICK HERE FOR DIRECTIONSPlease note, your Deposit doesn't constitute a payment. Please be sure to rate OK SERVICE, GOOD SERVICE OR EXCELLENT SERVICE/3-5 STARS/SMILEY FACES to complete transaction or ask for more help by clicking REPLY TO EXPERT. Positive feedback is always appreciated. Bonuses are welcome. Please note that if you have a subscription service you still need to to rate OK SERVICE, GOOD SERVICE OR EXCELLENT SERVICE/3-5 STARS/SMILEY FACES , however you are not charged again. Thank you.Please note the 1 to 2 faces(POOR AND BAD SERVICE) are a negative rating. Before choosing one of these, please reply first so that I can further help you
The problem misfiring is only when accelerating and completely stops misfiring if your not accelerating or lugging the engine down, do you still thing its valve adjustment?
HI,Yes, valves out of adjustment can cause many different misfire symptoms depending upon how far out of adjustment- ranging from constant misfire, misfire only under a load, misfire only when cold.with 210K miles on it and if never done, I have no doubt that this is the issuePlease note, your Deposit doesn't constitute a payment. Please be sure to rate OK SERVICE, GOOD SERVICE OR EXCELLENT SERVICE/3-5 STARS/SMILEY FACES to complete transaction or ask for more help by clicking REPLY TO EXPERT. Positive feedback is always appreciated. Bonuses are welcome. Please note that if you have a subscription service you still need to to rate OK SERVICE, GOOD SERVICE OR EXCELLENT SERVICE/3-5 STARS/SMILEY FACES , however you are not charged again. Thank you.Please note the 1 to 2 faces(POOR AND BAD SERVICE) are a negative rating. Before choosing one of these, please reply first so that I can further help you
Yes, valves out of adjustment can cause many different misfire symptoms depending upon how far out of adjustment- ranging from constant misfire, misfire only under a load, misfire only when cold.with 210K miles on it and if never done, I have no doubt that this is the issuePlease note, your Deposit doesn't constitute a payment. Please be sure to rate OK SERVICE, GOOD SERVICE OR EXCELLENT SERVICE/3-5 STARS/SMILEY FACES to complete transaction or ask for more help by clicking REPLY TO EXPERT. Positive feedback is always appreciated. Bonuses are welcome. Please note that if you have a subscription service you still need to to rate OK SERVICE, GOOD SERVICE OR EXCELLENT SERVICE/3-5 STARS/SMILEY FACES , however you are not charged again. Thank you.Please note the 1 to 2 faces(POOR AND BAD SERVICE) are a negative rating. Before choosing one of these, please reply first so that I can further help you
If you have any other questions, feel free to ask for more help by clicking the REPLY TO EXPERT button, otherwise please click the OK SERVICE, GOOD SERVICE OR EXCELLENT SERVICE smiley faces to pay for services rendered per customer agreement as this is a PAYSITE and expert is not paid for their time, knowledge or services until you do so.Please note, your Deposit doesn't constitute a payment. Please be sure to rate OK SERVICE, GOOD SERVICE OR EXCELLENT SERVICE/3-5 STARS/SMILEY FACES to complete transaction or ask for more help by clicking REPLY TO EXPERT. Positive feedback is always appreciated. Bonuses are welcome. Please note that if you have a subscription service you still need to to rate OK SERVICE, GOOD SERVICE OR EXCELLENT SERVICE/3-5 STARS/SMILEY FACES , however you are not charged again. Thank you.Please note the 1 to 2 faces(POOR AND BAD SERVICE) are a negative rating. Before choosing one of these, please reply first so that I can further help you
Well I adjusted the valves, they were all ab out .003 loose. Test drove the car, no improvement!!! When you accelerate the engine misfires but at about 3000 rpm something switches and the engine completely stops misfiring and takes off normally. Also if you accelerate slowly, it doesn't quite misfire. The big key as i see it is whatever switches at 3000 rpm? Since this is a vtec engine could it be that the vtec valve timing switching? what do you think?
HI,Is the only code P0300, P0301, P0302, P0303 or P0304?
yes
Hi,Vtec issues almost always set their own fault codes specific to the VTEC system. Usually this is either egr, which you had already cleaned and verified operation or valves out of adjustment.I am going to opt out and get another expert involved. Please dont respond until another expert responds back, otherwise it locks it to me and prevents another expert from helping
Hi,I’m a moderator for this topic. Your Professional has opted out and I wonder whether you’re still waiting for an answer. If you are, please let me know and I will do my best to find another Professional to assist you right away. If not, feel free to let me know and I will cancel this question for you. Thank you!
well the problem still exists and the answers so far haven't helped any
Different expert here what codes are stored in the ECM ?Also did this start happening after replacing the timing belt?
The codes up presently are P301, P302, P303, P304, P300The problem came up before the belt was changed, after this started I did replace the belt it had 100k on it. The original problem about six months ago was the vtec wasn't working, I forget its code, but I found the filter plugged, replaced it and that fixed that problem but then this problem came up. This problem is only obvious when accelerating or lugging the engine...above 3000 rpm no problems at all
Ok if it only start misfiring at 3000 rpm the issue is a faulty vtec solenoid valve or pressure switch were both of these replaced?
you have it backwards! If you accelerate hard, it misfires while you accelerate and at 3000 rpm it stops misfiring and the engine powers up and runs normally. If you accelerate slowly it doesn't misfire. The only parts replaced on the vtec was the filter
Ok still can be caused by the vtec pressure switch or solenoid valve . Also what is fuel pressure when this happens?
When the vtec filter plugged....the switch worked because I got the code for it. If anything is wrong with the vtex I would suspect the orifice under the rocker arm mount?...I can test the solenoid and pressure switch but believe they are fine. Do you know when the vtec is suppose to switch?I don't know the fuel pressure because I have been unable to find a special adapter to fit a 99 honda...I will try and fine one tomorrow
Ok try fuel pressure first . If the vtec was malfunctioning it would be causing a shudder at 3000 rpm and the engine light should be on. Also could be the ignition control module in the distributer or the coil or distributor itself . These need to be checked next .Please rate excellent service so I get credit for my help anything lower then ok service gives me negative feedback and I do not get compensated for my time thanks . If you need further assistance just let me know.
Experience: 13 year honda platinum level
Ok first of all rating me poor answer gives me negative feedback and I do not get compensated for my help which I think is not fair. I have gone above and beyond to help you with this issue at a very fast response rate. Also told you the most common issue . Also stated on last reply refrigerant level needs to be checked next. So you need to change you rating to excellent service so I get compensated for my help. The rating you gave was not fault to a professional with over 20 years in the field who is willing to help you in any way. If you need further help or any other questions let me know. Please change your rating so I get compensated for my time thanks.