99 Honda Accord misfire P1399, P0303, P0301

After a big dip in the weather this Honda started running terrible.
0:00 Intro
1:50 Checking it over
4:00 Checking Coil/Wires
5:56 Clean EGR
8:24 Map Sensor
10:16 Intake Hose
11:11 Diagnosing Injectors
14:52 Installing new Injector
20:00 Finish

[@gp185]

WoooHooo! Running like new again and no more wondering when the next blue moon is coming out! Replaced the fuel injector on #3, and we’re On The Road Again! I couldn’t wait to get back on the road again!Thank you again for the video, you really helped me!

[@robertscottII]

good to know.

[@gp185]

This is one heck of a video! My 99 is doing exactly the same thing with the engine code P0303 which is the misfire on #3 and funky idle. Every blue moon, the idle will straighten itself out and the car runs like brand new…but we haven’t had a blue moon in about a month now…(lol). I changed the cap, rotor, coil, wires, spark plugs, and still had a poor idle with the flashing engine light. I haven’t done the compression test, but did listen to each injector for the “clicking” noise, and all were clicking except #3. I checked the resistance readings for each injector, and they all read the same. I then checked the voltage on each connector, and none of them read 12 volts. I began thinking it was leading me to the harness or computer. I JUST found your video, and now I have hope! I’m going to order the injectors from eBay, change all 4, and hope and pray this fixes the problem! Thanks for the great video!

[@robertscottII]

Well I hope it works out. I know that feeling of chasing an issue over and over.

[@peguerordchannel3234]

How did it go?

[@gp185]

Replaced fuel injector #3, and everything was fine for about a week, then the poor idle returned, but this time code P0301 which is misfire on cylinder #1. Checked the fuel injector, and determined it was operating intermittently. Replaced the #1 injector, and car has been running fine ever since! (To check injector operation, start the car, using a long screwdriver, place the tip on the fuel injector, then place your ear near the handle and listen for a clicking sound, if no sound, then it’s likely that injector is not working, has poor connection, etc…just to be sure, I got a fuel injector from a vehicle in the salvage yard, and confirmed this was the issue, and it solved the problem). Are you also having an idle issue, misfire trouble codes P0301, 02, 03, or 04, and maybe P1399 (which is multiple misfiring)?

[@ohitselii]

Had these same codes. Turned out to be that the plugs were gapped to .050, distributor cap and rotor were completely burnt out and the wires were cracking at the boots. Still has original injectors at 319k miles

[@peguerordchannel3234]

Hello, can you tell me the part number and type of injectors that that car carries?

[@crazycookfyrelomenot]

going thru this now, getting p030X where X is 1-6. somehow 6 cyl misfire plus p1399. never see evidence of this except on low rough idle, dumped bg44k into my tank to clean that shit. replacing sensors as per BundyGarage video ( the other cause of this is heat soak issue due to dead sensors) hope its not my injectors...great video tho

[@sergiovalles8643]

Where you got the shop ?

[@capharlock1]

Did you calibrate de map sensor or you dont need to do that,thanks

[@robertscottII]

I did not.

[@Fred-xo3ku]

Why would you replace the plug wires if they are in spec from your meter readings? 🤔

[@robertscottII]

Cheap reliability. Plugs have 200,000 miles, and I was also concerned they could have an intermittent break.

[@sergiovalles8643]

I need help where you at?

[@markoivanovic2308]

did you fix it, what was the problem?

[@robertscottII]

Skip to injector chapter. Injector 3 was intermittently failing. Been driving for months without issue.

[@gp185]

This is one heck of a video! My 99 is doing exactly the same thing with the engine code P0303 which is the misfire on #3 and funky idle. Every blue moon, the idle will straighten itself out and the car runs like brand new…but we haven’t had a blue moon in about a month now…(lol). I changed the cap, rotor, coil, wires, spark plugs, and still had a poor idle with the flashing engine light. I haven’t done the compression test, but did listen to each injector for the “clicking” noise, and all were clicking except #3. I checked the resistance readings for each injector, and they all read the same. I then checked the voltage on each connector, and none of them read 12 volts. I began thinking it was leading me to the harness or computer. I JUST found your video, and now I have hope! I’m going to order the injectors from eBay, change all 4, and hope and pray this fixes the problem! Thanks for the great video!

[@mikebido3139]

@@gp185 did new injectors fix your problem?

[@gp185]

Yes, the fuel injector fixed the problem. I believe #3 and #1 were working intermittently. #1 would fool me because it would work most of the time. #3 would choose to stop working for weeks at a time, work for a day or two, then stop for weeks. Initially I had engine codes P0301, 0303, and 1399 with a blinking engine light. None of my ohmmeter checks came out exact (or even close) for the internal distributor components. So I replaced the coil, and no fix. Changed the distributor cap, rotor, wires and plugs, no fix, but when I cleared the codes, started the car, it only had engine code P0303. Extending my search further, I checked each injector with the engine started and listening using a long screwdriver. I heard the “clicking” sound on 1, 2, 4, but nothing from #3. I then went a little further and checked each injector and connector with the ohmmeter, but NONE of the readings were what they should’ve been. At that point I was floored, and thinking the computer wasn’t sending the correct voltage (P1399 is multiple misfire code). At this point, since I still wasn’t sure of the cause, I decided to get a fuel injector from the salvage yard to see if this would help (I had already spent about $175 on the other parts). I replaced the #3 injector, and it fixed the poor idle problem. I cleared the code, and everything was fine…for about a week, before the poor idle and blinking engine light returned. I checked the engine code, and it showed P0301 (a #1issue). I then took out my long screwdriver and checked each fuel injector, and #1 had no “clicking” sound. I then had someone else listen, and strangely enough, #1 was clicking again! At that point, I knew that my slight “tap” on the injector had helped it start working again. That was about two weeks ago, it’s still working, but the engine light just came on two days ago, but it’s not blinking, and the idle is still good. My intention is to replace all four injectors, but haven’t had the time to work on it. I hope this helps. And just for informational purposes, I did a lot of research and watched a lot of videos before I found this KZbin video, which helped the most!! (Time is going by so fast, that I may not have the correct day or week information correct in this post 🤣)

[@yoshiterumaeda3041]

Mine was cracked injector o-ring…

[@allornothingang]

I HAVE A 1999 HONDA ACCORD LX 6 CYLINDER AND I HAD SOMEONE CHANGE THE SPARK PLUGS AND SPARK PLUG WIRES AND NOW MY CAR WONT START AND I REALLY NEED MY CAR FOR WORK, CAN YOU PLEASE LET ME KNOW WHAT THE PERSON DID WRONG?

[@robertscottII]

Hard to say. Maybe got plug wires crossed.

[@allornothingang]

@@robertscottII THANK YOU SO MUCH, I REPLACED THE SPARK PLUGS AND SPARK PLUG WIRES AND IT RUNS WAY BETTER THAN BEFORE BUT IT STILL SPUTTERS, CAN YOU GIVE ME AN IDEA OF WHAT YOU THINK ALSO CAN BE THE PROBLEM?

[@robertscottII]

@@allornothingang any codes?

[@cmajic5968]

vale adjustment