Engine misfiring

Hello,

This happens when the MAP sensor gets a little off but not enough to trigger a light. Here is a diagram below so you can perform the replacement.

Please check out this guide

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Check out the diagrams (below). Please let us know if you need anything else to get the problem fixed.

Thanks you so much! I did this and it worked perfect for my car never ran better. I love this site. :)

Hi. I have a troubleshooting and nobody could help me about it. It has a misfire detection on scanner, but I changed the ignition coils, spark plug and does not work. Every time is shaking. I do not like that, because is a great car. Please I need your help. I went to the mechanic but he only wants my money and cannot help me.

Thanks

You also have to consider fuel and compression, especially at the mileage you listed. The fault code should specify which cylinder is misfiring. Swap that injector with one of the other ones and see if the misfire moves to the other cylinder.

Do a compression test.

https://www.2carpros.com/articles/how-to-test-engine-compression

2003 Acura TL - Hesitates between 20-30 miles/hr (rarely higher speeds) and can **** you around until car seems to grab hold and go. Giving it more gas sometimes helps. Doesn't always do this. Seems to be worse in warmer weather. Was told it was my EGR valve by Acura. Replaced, but did not fix the problem.

Has the check engine light come on? Have you checked fuel pump pressure?

No and no.

Any of you guys run into a low speed miss on 2003TL? It started 2-3 mos. ago
.. First occasionally, now everyday. At about 20-35 mph and light throttle,
the car starts to buck until you change throttle positon, then it responds
normal. It runs fine at full throttle at least to 115 mph and idles smooth,
Avg. mileage around 25 mpg, same as always. Has 84K mi. on it. Gonna pull
the plugs and go from there. Thanks!

I might suggest a plug look as well. See if there is any oil in the plug holes. I might look at replacing the wires.

[quote:39048dbe12="arod1682000"]Any of you guys run into a low speed miss on 2003TL? It started 2-3 mos. ago
.. First occasionally, now everyday. At about 20-35 mph and light throttle,
the car starts to buck until you change throttle positon, then it responds
normal. It runs fine at full throttle at least to 115 mph and idles smooth,
Avg. mileage around 25 mpg, same as always. Has 84K mi. on it. Gonna pull
the plugs and go from there. Thanks![/quote:39048dbe12]

The problem it may be a clogged EGR ports
Are you getting a misfire codes
You should check if you have any codes
I will look for the bulletin and will post it

The problem it may be a clogged EGR ports Are you getting a misfire codes You should check if you have any codes I will look for the bulletin and will post it[/quote:96be84263f]

Hello I have a 2001 Acura Tl and after I have driven it for awhile then let it sit for an hour or so or sometimes just shutting it off then starting it back up,it will run a bit rough so in order to straighten it up I have to rev the engine up to get it to smooth back up and sometimes it throws a code. I have taken it to autozone and had them run a diagnostic on it and it comes up with cylinder 1 and 2 misfire. It doesn't do this that often but when it does the check engine light will come on but will shut of pretty quickly after coming on Thanks for any help ;)

Hi FUNGUY4,

Misfiring can be due to the ignition, fuel system or engine mechanicals.

Most common would be the ignition system concerning the spark plugs and related parts. Have them checked and repair as necessary.

If it is fuel related, it could be the injectors or fuel pressure.

Do you have any overheating or coolant losses issues?

HI, no I have no issues with overheating or any of the such so I think I have ruled out any head gasket issue. I bought the car when it had 108,000k, and in the maintenance records I have found no reciepts for a tune up so I am going to try to do a tune-up anyway since it probably needs one and see if that fixes the issue then I will go from there if not. Thanks for your help KHLow2008

Engine Performance problem
2001 Acura TL 6 cyl Front Wheel Drive 153000 miles

my tl has all 6 cylnders misfiring and is sluggish as hell. takes almost 30 seconds to get to 50 mph. i dont want to get burned by a mechanic so was looking for some info on what may be the problem. thanks for everyones time

if all cylinders are misfiring then there could be damage to the cylinder head. you will need to have a leakdown and compression test performed on the cylinders.

i recently took my tl for a tuneup and 3 days after it was done my car started shaking and the codes told me most of my cylinders were misfiring.Do you think the mechanic messed up the tuneup and caused this?

Hi acuratltrouble. Welcome to the forum. If it's the mechanic's fault, why did it run fine for three days? Every mechanic fears the "ever since" syndrome. That's where anything that goes wrong days or weeks after he touched the car is his fault. There is very little involved today in a tune-up compared to thirty years ago. That's not to say, however, the new problem couldn't be related to the recent service. First you need to find out what the cause of problem is before assigning blame. A new spark plug could have a cracked insulator. That's not really the mechanic's fault but it is something he will take care of. A vacuum hose could have been knocked off during the service. If the rubber is old and deteriorated, disturbing it while removing other parts could have loosened it and it took three days to become disconnected due to normal engine vibration. Again, this is something he will take care of but it's not fair to blame him for overlooking a hose that he didn't touch and wasn't causing a problem when he had the car. Too many people have the attitude "well, he SHOULD have seen it". That means he should have been psychic! We really aren't that good. :)

Your new problem falls into one of three categories. It could be totally unrelated to the recent service, it could be an unintended byproduct of the recent service, or it could be a result of the recent service. A reputable shop / mechanic will determine the cause of the problem and do everything possible to make it right because they want you to be happy and come back again, but they also have to look out for the business and not give away too much for free. It can be very hard for them to have to explain why the new problem is just that and it's something you'll have to pay for.

Next, if their work led to the new problem, reputable shops will apologize and fix it at their expense. New parts can be defective, and some less-expensive aftermarket parts just don't work as expected in some cars. In the words of one manufacturer's trainer, "we not only sell you new parts, we provide them pre-broken". When this is the case, most shops will not charge additional labor to replace a defective new part. They CAN legitimately charge if a new part is needed that wasn't previously installed.

If something was damaged or done incorrectly that led to the new problem, reputable shops will repair it at their expense and often do something extra for you such as offering a free oil change. The key is the cause of the problem has to be identified first. Even then, less-than-reputable shops can just as easily make up a story about why the new problem isn't their fault. Usually those shops are already well-known, but regardless, they are the ones that give the entire industry a bad name.

The first thing you should do is contact the shop that did the tune-up and explain what is happening. They will most likely offer to look at it as soon as possible. If they claim it is not their fault and it's going to be an expensive repair, the next thing would be to get a second opinion from a different shop. Most shops don't like to cut down their competitors because making a competitor look small doesn't make them look big. I'd suggest you don't even mention the name of the shop that did the tune-up. If that first one IS less than reputable, the second shop may be predisposed to looking extra hard for something to blame on them that really might not be deserved.

caradiodoc

I installed a new EGR valve, cleaned the intake manifold including the EGR port. Put SeaFoam in the gas, oil, and a little thru the vacume lines. I'm not getting any of the P0300 thru P0306 or P0401 DTCs anymore. BUT I'm still getting the P1399 DTC w/ a mild skip under load. The plugs are new Bosch 4428 +4 PLatinums What else could be causing the P1399? Or do I just need to let the SeaFoam work its" way thru the systems?

P1399 is a temporary code for misfiring and the misfiring code should be back sooner or later.

What is the plug gap setting?

Have you tested the coils?

The Bosch 4428s are the "NO-Gap" style plugs and I haven't messed w/ that. I was going to test the coils if I kept getting specific misfires (P0301-P0306), but those DTC(s) went away. Now it just the P1399. Is there a specific procedure to test the coil itself, other than faul isolating thru the wiring between the plug-connector and the ECM? I can do that, but didn't want to as there's no specific misfire to id which cylinder I should testing?

Additionally, someone told me to replace the Bosch w/ the NGK(s). I thought the Bosch were pretty good plugs. But if they're part of the problem, I'ss certainly replace them.

The gapping might not be as specified. I would try replacing them first to see if it solves the problem.

Have the compression tested if changing the plugs does not help.

Coils can be tested for resistance but if it is misfiring on all cylinders, the likelyood of all coils failing at the same time is almost zero.

Apart from compression, check the fuel pressure and exhaust system.

Thnx-a-million. I'll put new NGK(s) in and see.

You're welcome.

Good luck and have a nice day.

Put in new NGK Platinum plugs gapped to .44, but still getting multiple misfires. Can't do compression check myself and not getting any codes for fuel delivery system errors. So I gotta go to my pro I guess. Thnx for all the help guys!

The car has no power and idles rough. What would cause this misfire problem on all cylinders?
Thanks

P0300 Random misfire/P0306 no. 6 cyl

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

Did you check the fuel pressure?

No. But a mech friend said if one Coil/boot causes a misfire it sometimes confuses the computer & reports multiple cylinders. He suggested unplugging coils 1-@-a-time while idling to see if I can isolate the skip to a single cylinder. Duh! I should've thought of that istead of relying on the DTC to try and isolate. Thnx.

That was it! Unplugged #2 cyl w/ eng idling and got no chnge. All others RPM(s) dropped. Swapped coil w/ #5. Now no change in RPM when #5 unplugged. replaced coil. skip gone! So... EGR fixed, intk mnifld cleaned. EGR prt cleaned out. good NGK plugs. Skip GONE! Runs like a new Singer Sewing Machine!! Thnx for all the help!!

You're welcome.

Glad to know you have fixed the problem.

Have a nice day.

I replaced my O2 (bank 1) sensor and a week later my vehicle began misfiring on all cylinders. I ran the codes and it said P0301, P0302, P0303, P0304, P0305, and P0306 - all cylinders misfiring - as well as the Multiple Misifre code of course. It also registered P1399 - Manufacturer Control Ignition System or Misfire - which is not an acura trouble code. I therefore replaced all my spark plugs, my EGR Valve, and one Coil Pack that had a hairline fracture. I cleaned my EGR Valve Ports using Sea Foam twice and used MAF Sensor cleaner to clean the MAP Sensor. The vehicle still registered P1399. Shortly after, P0305 registered followed by the remaining P030's. The vehicle feels like it's misfiring. My catalytic converter needs replaced soon. What can be the cause of the misfire? And what would cause the P1399 trouble code?

check/clean/replace also check the wiring

CKP Sensor......Behind crankshaft pulley, attached to oil pump.
Crankshaft Position (CKP) Sensor
Sensor detects speed and position of crankshaft. Used for fuel injection timing and ignition timing.

Check freeze frame data. Perform PCM reset procedure and clear freeze frame data (if present) and DTC(s). See PCM RESET PROCEDURE/CLEARING CODES under SELF-DIAGNOSTIC SYSTEM. Exchange spark plug from suspect cylinder with one from another cylinder. Connect SCS service connector. See Fig. 1. Test drive vehicle several times in freeze frame data range. If there is no freeze frame data of misfiring, test drive vehicle under various conditions and try to duplicate malfunction. If DTCs P0301, P0302, P0303, P0304, P0305, P0306 or temporary DTC P1399 are set, go to next step. If DTCs P0301, P0302, P0303, P0304, P0305, P0306 or temporary DTC P1399 are not set, problem is intermittent, possibly due to fouling spark plug. Misfire is not detected at this time. If misfire follows spark plug to different cylinder, replace spark plug. If misfire remains in same cylinder, go to next step.
Exchange fuel injector from suspect cylinder with one from another cylinder. Let engine idle for 2 minutes. Test drive vehicle several times in freeze frame data range. If there is no freeze frame data of misfiring, test drive vehicle under various conditions and try to duplicate malfunction.
If DTC P0301, P0302, P0303, P0304, P0305 or P0306 is not indicated, misfire condition is not detected at this time. Possible intermittent fuel injector poor connection. If misfire follows injector to another cylinder, replace faulty fuel injector. If misfire remains in same cylinder check valve adjustment, cylinder leak down, engine compression and Crankshaft Position (CKP) sensor. Repair as necessary.