Multiple Random Cylinder misfire
I’m at a loss on this one I need some help,I have a stock 1999 Honda civic Ex D16y8, I recently replaced my valve cover gasket and my Vtec solenoid gasket, I also decided to replace my spark plugs while i was in there. I did not check my spark plug gap because they are pre gapped (I know I should have checked it anyways) and I torqued them to spec, flash forward 2 days the Honda bond is dry so I start my car up and it’s running perfectly normal, now here is where I messed up, my distributor was making a loud chirping sound it sounded just like a bird so I messed with the distributor bolts and the cap bolts and the chirping went away but my car was running perfectly normal, so i drive my car for about an hour and I notice that my car is misfiring every once in a while at idle not often at all and only noticeable at idle, while I was out I helped an old lady jump start her car and I started to head home about 45 minutes away, after 30 minutes of driving my misfires got a lot worse I mainly noticed it after getting off the highway I got a p1399 and a p0300 and a cyl 1 and 4 misfire code as well, so the next day I did some research and figured out that I might have messed up my ignition timing by messing with the distributor bolts but here’s my thing, and I’m pretty new to doing all my own maintenance and stuff so please don’t judge me too hard but I feel like my ignition timing would have been messed up as soon as I messed with the distributor, so I checked my ignition timing and it was off a bit so I tried adjusting it but no matter how I moved the distributor it won’t run right even though the ignition timing is lined up I’m not sure how all it works so if someone could help point me in the right direction or recommend stuff for me to look at that would be great, my car has new ngk iridium spark plugs new dizzy rotor and cap thank you in advance
(car has 134,000 miles)
(car has 134,000 miles)
Last edited by JDMFLORIDA; Mar 5, 2025 at 06:40 PM.
Originally Posted by JDMFLORIDA;[url=tel:52942281
52942281[/url]]I’m at a loss on this one I need some help,I have a stock 1999 Honda civic Ex D16y8, I recently replaced my valve cover gasket and my Vtec solenoid gasket, I also decided to replace my spark plugs while i was in there. I did not check my spark plug gap because they are pre gapped (I know I should have checked it anyways) and I torqued them to spec, flash forward 2 days the Honda bond is dry so I start my car up and it’s running perfectly normal, now here is where I messed up, my distributor was making a loud chirping sound it sounded just like a bird so I messed with the distributor bolts and the cap bolts and the chirping went away but my car was running perfectly normal, so i drive my car for about an hour and I notice that my car is misfiring every once in a while at idle not often at all and only noticeable at idle, while I was out I helped an old lady jump start her car and I started to head home about 45 minutes away, after 30 minutes of driving my misfires got a lot worse I mainly noticed it after getting off the highway I got a p1399 and a p0300 and a cyl 1 and 4 misfire code as well, so the next day I did some research and figured out that I might have messed up my ignition timing by messing with the distributor bolts but here’s my thing, and I’m pretty new to doing all my own maintenance and stuff so please don’t judge me too hard but I feel like my ignition timing would have been messed up as soon as I messed with the distributor, so I checked my ignition timing and it was off a bit so I tried adjusting it but no matter how I moved the distributor it won’t run right even though the ignition timing is lined up I’m not sure how all it works so if someone could help point me in the right direction or recommend stuff for me to look at that would be great, my car has new ngk iridium spark plugs new dizzy rotor and cap thank you in advance
(car has 134,000 miles)
(car has 134,000 miles)
Definitely sounds like the timing is off if you moved the distributor, and it’s an easy fix if you have a timing light.
you do need to short the testing port next to the ECU to make the timing stick, as the ECU will adjust timing whenever you move the dizzy around.
There’s a great walk through on this site, probably a sticky.
Definitely check your plugs, both for proper gap, and to determine if they’re lean, or rich. You could also have put a plug wire in the wrong location, though I’d expect that to make it run like absolute dog crap. On that note, how old are the wires, and are they quality? (NGK)
What plugs did you install? I hope you didn’t buy them on that jungle website, as they’re often counterfeit, and cause exactly the type of problem you describe.
ETA: damn, 134k..!???? That’s a LOW mile ride bro..!
take a look at the spark plug wells, Im wondering if when you changed the valve cover gasket, that they are leaking oil onto the plugs, filling the well causing your missfire
First, I’m not sure what you used Hondabond for..? Are you just referring to the 4 spots around the camshaft?
Definitely sounds like the timing is off if you moved the distributor, and it’s an easy fix if you have a timing light.
you do need to short the testing port next to the ECU to make the timing stick, as the ECU will adjust timing whenever you move the dizzy around.
There’s a great walk through on this site, probably a sticky.
Definitely check your plugs, both for proper gap, and to determine if they’re lean, or rich. You could also have put a plug wire in the wrong location, though I’d expect that to make it run like absolute dog crap. On that note, how old are the wires, and are they quality? (NGK)
What plugs did you install? I hope you didn’t buy them on that jungle website, as they’re often counterfeit, and cause exactly the type of problem you describe.
ETA: damn, 134k..!???? That’s a LOW mile ride bro..!
Definitely sounds like the timing is off if you moved the distributor, and it’s an easy fix if you have a timing light.
you do need to short the testing port next to the ECU to make the timing stick, as the ECU will adjust timing whenever you move the dizzy around.
There’s a great walk through on this site, probably a sticky.
Definitely check your plugs, both for proper gap, and to determine if they’re lean, or rich. You could also have put a plug wire in the wrong location, though I’d expect that to make it run like absolute dog crap. On that note, how old are the wires, and are they quality? (NGK)
What plugs did you install? I hope you didn’t buy them on that jungle website, as they’re often counterfeit, and cause exactly the type of problem you describe.
ETA: damn, 134k..!???? That’s a LOW mile ride bro..!
Last edited by JDMFLORIDA; Mar 14, 2025 at 11:17 AM.
pull the plugs and gap them correctly
take off the distributor cap and check the electrodes for any chunk of electrode missing and check the rotor for missing parts, also check the little black dot in the cap, make sure it springs back and forth
you say you replaced the spark plug wires and now have a miss at 1 and 4, make sure the wires are in the distributor correctly 1 and 4 are directly across from each other. I know you said you double checked the wires,
DO IT ANYWAY
po1399 is just honda speak for multiple random missfire, sometimes the IAC gets clogged up to the point that is will stick open causing a lean missfire, clean it with carb cleaner and a fine brush
Do all that and let us know
take off the distributor cap and check the electrodes for any chunk of electrode missing and check the rotor for missing parts, also check the little black dot in the cap, make sure it springs back and forth
you say you replaced the spark plug wires and now have a miss at 1 and 4, make sure the wires are in the distributor correctly 1 and 4 are directly across from each other. I know you said you double checked the wires,
DO IT ANYWAY
po1399 is just honda speak for multiple random missfire, sometimes the IAC gets clogged up to the point that is will stick open causing a lean missfire, clean it with carb cleaner and a fine brush
Do all that and let us know
pull the plugs and gap them correctly
take off the distributor cap and check the electrodes for any chunk of electrode missing and check the rotor for missing parts, also check the little black dot in the cap, make sure it springs back and forth
you say you replaced the spark plug wires and now have a miss at 1 and 4, make sure the wires are in the distributor correctly 1 and 4 are directly across from each other. I know you said you double checked the wires,
DO IT ANYWAY
po1399 is just honda speak for multiple random missfire, sometimes the IAC gets clogged up to the point that is will stick open causing a lean missfire, clean it with carb cleaner and a fine brush
Do all that and let us know
take off the distributor cap and check the electrodes for any chunk of electrode missing and check the rotor for missing parts, also check the little black dot in the cap, make sure it springs back and forth
you say you replaced the spark plug wires and now have a miss at 1 and 4, make sure the wires are in the distributor correctly 1 and 4 are directly across from each other. I know you said you double checked the wires,
DO IT ANYWAY
po1399 is just honda speak for multiple random missfire, sometimes the IAC gets clogged up to the point that is will stick open causing a lean missfire, clean it with carb cleaner and a fine brush
Do all that and let us know
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