2011 2.5 160K, #2 misfire
#1
02-13-2022, 12:58 PM
2011 2.5 160K, #2 misfire
Hey all,
Well maintained,synth fluids,etc.2nd owner since 98K.
Mysterious misfire.
Bad miss -especially at 2K rpm's, hot or cold.
Replaced w/OE: plugs ,coils,injectors.
#2 comp is 15# lower than others; 1,3,4 =180.
Bore scope not definitive.
NO coolant/oil mixing.
Suggestions?
Thanks.
Well maintained,synth fluids,etc.2nd owner since 98K.
Mysterious misfire.
Bad miss -especially at 2K rpm's, hot or cold.
Replaced w/OE: plugs ,coils,injectors.
#2 comp is 15# lower than others; 1,3,4 =180.
Bore scope not definitive.
NO coolant/oil mixing.
Suggestions?
Thanks.
#2
02-13-2022, 06:27 PM
Do we know if there is a loss of power to either the coil or the injector?
If it will misfire at idle it should be easy to verify if coil is getting power and ground to fire.
Do you have any kind of test equip to use?
If it will misfire at idle it should be easy to verify if coil is getting power and ground to fire.
Do you have any kind of test equip to use?
#4
02-14-2022, 09:57 AM
Lets start with the simple test light.
Verify if you are getting continuous power to both the coil and injector.
Verify that you are getting a ground, when supposed to, to both coil and injector.. Do you know how to do that?
If you don't find anything wrong there , get back to us and we will continue.
Verify if you are getting continuous power to both the coil and injector.
Verify that you are getting a ground, when supposed to, to both coil and injector.. Do you know how to do that?
If you don't find anything wrong there , get back to us and we will continue.
#5
02-15-2022, 10:27 PM
Hanky, power to both coil and injector. Noid light verifies injector,injecting.
Coil - Guess I'll have to probe that tomorrow...
A mechanic friend, said that a "power balance" test, showed a 40% drop in power from #2.
He also stated: ALL injectors 'fire' at same time - ? > Coils?
I don't see how that's so, as they would all have same colored 'trigger' wire,no?
Jeff
Coil - Guess I'll have to probe that tomorrow...
A mechanic friend, said that a "power balance" test, showed a 40% drop in power from #2.
He also stated: ALL injectors 'fire' at same time - ? > Coils?
I don't see how that's so, as they would all have same colored 'trigger' wire,no?
Jeff
#6
02-16-2022, 07:00 AM
Hi Jeff,
To answer your question, older versions fired the whole bank of injectors , your vehicle has sequential injector firing, which means they fire individually. Therefore each injector would have it own trigger wire coming from the PCM. AND they are all different colors. Guys do manage to mix up the plugs , however, and create some unusual problems.
Going back to the misfire problem, you did verify the coil is getting its signal to fire and not sure if you verified that injector was getting its signal.
Compression can affect cyl output ,but I have seen lower readings not produce a hi speed miss.
Might be a good idea to have a leak down test done to isolate where the compression is going. Can you get this done? A valve spring problem can produce this type problem, but we always want to prove/verify what we suspect before taking things apart.
If you cannot find the cause for the misfire, and I would not do this unless all other tests came back good, and that is to remove the valve cover for that cyl and physically closely check the valve springs for that cyl. Sometimes they break down at the bottom were it is difficult to see unless you know what you are looking for.
Best to take one thing at a time.
To answer your question, older versions fired the whole bank of injectors , your vehicle has sequential injector firing, which means they fire individually. Therefore each injector would have it own trigger wire coming from the PCM. AND they are all different colors. Guys do manage to mix up the plugs , however, and create some unusual problems.
Going back to the misfire problem, you did verify the coil is getting its signal to fire and not sure if you verified that injector was getting its signal.
Compression can affect cyl output ,but I have seen lower readings not produce a hi speed miss.
Might be a good idea to have a leak down test done to isolate where the compression is going. Can you get this done? A valve spring problem can produce this type problem, but we always want to prove/verify what we suspect before taking things apart.
If you cannot find the cause for the misfire, and I would not do this unless all other tests came back good, and that is to remove the valve cover for that cyl and physically closely check the valve springs for that cyl. Sometimes they break down at the bottom were it is difficult to see unless you know what you are looking for.
Best to take one thing at a time.
#7
02-17-2022, 07:21 AM
misfire
Hi Jeff,
To answer your question, older versions fired the whole bank of injectors , your vehicle has sequential injector firing, which means they fire individually. Therefore each injector would have it own trigger wire coming from the PCM. AND they are all different colors. Guys do manage to mix up the plugs , however, and create some unusual problems.
Going back to the misfire problem, you did verify the coil is getting its signal to fire and not sure if you verified that injector was getting its signal.
Compression can affect cyl output ,but I have seen lower readings not produce a hi speed miss.
Might be a good idea to have a leak down test done to isolate where the compression is going. Can you get this done? A valve spring problem can produce this type problem, but we always want to prove/verify what we suspect before taking things apart.
If you cannot find the cause for the misfire, and I would not do this unless all other tests came back good, and that is to remove the valve cover for that cyl and physically closely check the valve springs for that cyl. Sometimes they break down at the bottom were it is difficult to see unless you know what you are looking for.
Best to take one thing at a time.
To answer your question, older versions fired the whole bank of injectors , your vehicle has sequential injector firing, which means they fire individually. Therefore each injector would have it own trigger wire coming from the PCM. AND they are all different colors. Guys do manage to mix up the plugs , however, and create some unusual problems.
Going back to the misfire problem, you did verify the coil is getting its signal to fire and not sure if you verified that injector was getting its signal.
Compression can affect cyl output ,but I have seen lower readings not produce a hi speed miss.
Might be a good idea to have a leak down test done to isolate where the compression is going. Can you get this done? A valve spring problem can produce this type problem, but we always want to prove/verify what we suspect before taking things apart.
If you cannot find the cause for the misfire, and I would not do this unless all other tests came back good, and that is to remove the valve cover for that cyl and physically closely check the valve springs for that cyl. Sometimes they break down at the bottom were it is difficult to see unless you know what you are looking for.
Best to take one thing at a time.
t bottom of stroke.? Albeit w/ piston at bottom of stroke.? Nothing according to him.
Noid light was firing at connector.
Coil: I'll check for power/ground.- If I pull plug/coil and lay on head, should show firing.?
V. Cover has been off,cannot see springs below cams and follower/shims.>> Was surprised to find these were NOT hydraulic.
>Online searches show more than a few people with similar problem. Turned out to be valve recession! Haven't come across any with a broken spring though,which is what I was leaning towards.
Keep you posted.
I'm outside in my drive,weather moving in.....
Jeff
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