Jazz 2015 ongoing misfire please HELP!

[emmas777]

Hey guys,

I need help for my Honda Jazz 2015 which has been misfiring on & off for some time now.

No error codes. Have done the following:
replaced petrol filter, battery, spark plugs & coils, intake manifold cleaned, fuel injectors cleaned & I attempted an ECU reset (not sure if I’ve done this properly though, would love some advice, removed 15a #20 fuse for 10mins).

Starts well, idles well, drives under power well. Misfires under light throttle between 13-1800RPMs. 200,000kms full service history. Can’t get it to fault when I take it to Honda service.

Any ideas what could be going on? Would love some advice. Thank you!

[Jocko]

Welcome. By intake manifold cleaned do you mean the EGR valve. If that is stuck open that could lead to a midfire.

[culzean]

Try fitfreaks in USA they often have answers

https://www.fitfreak.net

[emmas777]

Welcome. By intake manifold cleaned do you mean the EGR valve. If that is stuck open that could lead to a midfire.

Hey Jocko, thanks for that. No haven’t cleaned the EGR. Honda said they cleaned the “intake manifold” not quite sure what that is. I’m a mechanic but from decades ago, things are so different now, feel a bit lost at times. Just looking at how to clean the EGR now. Cheers!

[emmas777]

Try fitfreaks in USA they often have answers

https://www.fitfreak.net

Thanks mate, will check them out

[culzean]

Welcome. By intake manifold cleaned do you mean the EGR valve. If that is stuck open that could lead to a midfire.

Hey Jocko, thanks for that. No haven’t cleaned the EGR. Honda said they cleaned the “intake manifold” not quite sure what that is. I’m a mechanic but from decades ago, things are so different now, feel a bit lost at times. Just looking at how to clean the EGR now. Cheers!

EGR stands for exhaust gas recirculation and the valve should be closed below about 3000 revs,  it is there to allow a bleed of exhaust manifold gas into inlet manifold to cool combustion down to reduce nitrogen oxides in exhaust.  If it fails to close properly when it should it is like having an air leak in inlet manifold, which plays havoc with fuelling at lower revs.  Strangely the valve is more likely to stick on cars that do local mileage and never go above 3000 revs, if the valve is geting opened and closed regularly it keeps it in good shape.

Plenty of info on forum about EGR, do a search.

[TnTkr]

Try fitfreaks in USA they often have answers

https://www.fitfreak.net

Thanks mate, will check them out

There is lots of information in Fitfreak-forums, but it's good to remember that they only have 1.5 liter engine in North-America. There are differences between GK Jazz 1.3 and 1.5 engines, although both are L-series DOHC i-VTEC engines. For example 1.3 uses Atkinson-cycle in low rpms but 1.5 not.

[Jocko]

1.5 is common in Australia as well.

[ColinB]

Hey guys,

I need help for my Honda Jazz 2015 which has been misfiring on & off for some time now.

No error codes. Have done the following:
replaced petrol filter, battery, spark plugs & coils, intake manifold cleaned, fuel injectors cleaned & I attempted an ECU reset (not sure if I’ve done this properly though, would love some advice, removed 15a #20 fuse for 10mins).

Starts well, idles well, drives under power well. Misfires under light throttle between 13-1800RPMs. 200,000kms full service history. Can’t get it to fault when I take it to Honda service.

Any ideas what could be going on? Would love some advice. Thank you!

Just a thought, but are you sure it’s a misfire? There is another thread...
https://clubjazz.org/forum/index.php?topic=12326.0
... that describes a hesitation at about the rev range you describe. Best opinion there seems to be that it’s a consequence of how the engine is designed, and it’s more noticeable on some cars than others (or maybe some drivers are more sensitive to it than others).

[jazzaro]

Welcome. By intake manifold cleaned do you mean the EGR valve. If that is stuck open that could lead to a midfire.

Hey Jocko, thanks for that. No haven’t cleaned the EGR. Honda said they cleaned the “intake manifold” not quite sure what that is. I’m a mechanic but from decades ago, things are so different now, feel a bit lost at times. Just looking at how to clean the EGR now. Cheers!

EGR stands for exhaust gas recirculation and the valve should be closed below about 3000 revs,  it is there to allow a bleed of exhaust manifold gas into inlet manifold to cool combustion down to reduce nitrogen oxides in exhaust.  If it fails to close properly when it should it is like having an air leak in inlet manifold, which plays havoc with fuelling at lower revs.  Strangely the valve is more likely to stick on cars that do local mileage and never go above 3000 revs, if the valve is geting opened and closed regularly it keeps it in good shape.

Plenty of info on forum about EGR, do a search.

Check your engine code, L15 engines can have direct or port injection, Otto or Atkinson cycle  depending from their market and box. In Europe GK Jazz have 1.3 port injection and Atkinson Cycle, 1.5 only direct Injection, in some other markets Jazz GK can have a 1.5 port injection.
Direct injection engines, such as the Jazz 1.5, can suffer about valve carbon buildup, https://clubjazz.org/forum/index.php?topic=12119.0 this can bring the engine to misfiring.

[emmas777]

Welcome. By intake manifold cleaned do you mean the EGR valve. If that is stuck open that could lead to a midfire.

Hey Jocko, thanks for that. No haven’t cleaned the EGR. Honda said they cleaned the “intake manifold” not quite sure what that is. I’m a mechanic but from decades ago, things are so different now, feel a bit lost at times. Just looking at how to clean the EGR now. Cheers!

EGR stands for exhaust gas recirculation and the valve should be closed below about 3000 revs,  it is there to allow a bleed of exhaust manifold gas into inlet manifold to cool combustion down to reduce nitrogen oxides in exhaust.  If it fails to close properly when it should it is like having an air leak in inlet manifold, which plays havoc with fuelling at lower revs.  Strangely the valve is more likely to stick on cars that do local mileage and never go above 3000 revs, if the valve is geting opened and closed regularly it keeps it in good shape.

Plenty of info on forum about EGR, do a search.

I’m a driving instructor so a lot of miles are done under 3000 revs, could be a thing, right? Hey, thanks for info & explanation on the EGR. I cleaned it out a couple times & surprisingly I’ve not had any misfires today. Sometimes it may do this for a day then return, however yesterday was pretty bad, so for it to stop completely is unusual. Stoked that you mentioned all this & that I may have a solution. Never seen mention of EGR on any Honda misfire google search so glad I found you guys!
It drives me nuts because I’m in the car for 10hrs a day so thanks for saving my sanity mate!

[emmas777]

Hey guys,

I need help for my Honda Jazz 2015 which has been misfiring on & off for some time now.

No error codes. Have done the following:
replaced petrol filter, battery, spark plugs & coils, intake manifold cleaned, fuel injectors cleaned & I attempted an ECU reset (not sure if I’ve done this properly though, would love some advice, removed 15a #20 fuse for 10mins).

Starts well, idles well, drives under power well. Misfires under light throttle between 13-1800RPMs. 200,000kms full service history. Can’t get it to fault when I take it to Honda service.

Any ideas what could be going on? Would love some advice. Thank you!

Just a thought, but are you sure it’s a misfire? There is another thread...
https://clubjazz.org/forum/index.php?topic=12326.0
... that describes a hesitation at about the rev range you describe. Best opinion there seems to be that it’s a consequence of how the engine is designed, and it’s more noticeable on some cars than others (or maybe some drivers are more sensitive to it than others).

This is interesting because I am a driving instructor & the kids often hover at low revs doing manoeuvres & drive erratically etc. I’ll check out the link, thanks!

[emmas777]

Welcome. By intake manifold cleaned do you mean the EGR valve. If that is stuck open that could lead to a midfire.

Hey Jocko, thanks for that. No haven’t cleaned the EGR. Honda said they cleaned the “intake manifold” not quite sure what that is. I’m a mechanic but from decades ago, things are so different now, feel a bit lost at times. Just looking at how to clean the EGR now. Cheers!

EGR stands for exhaust gas recirculation and the valve should be closed below about 3000 revs,  it is there to allow a bleed of exhaust manifold gas into inlet manifold to cool combustion down to reduce nitrogen oxides in exhaust.  If it fails to close properly when it should it is like having an air leak in inlet manifold, which plays havoc with fuelling at lower revs.  Strangely the valve is more likely to stick on cars that do local mileage and never go above 3000 revs, if the valve is geting opened and closed regularly it keeps it in good shape.

Plenty of info on forum about EGR, do a search.

Check your engine code, L15 engines can have direct or port injection, Otto or Atkinson cycle  depending from their market and box. In Europe GK Jazz have 1.3 port injection and Atkinson Cycle, 1.5 only direct Injection, in some other markets Jazz GK can have a 1.5 port injection.
Direct injection engines, such as the Jazz 1.5, can suffer about valve carbon buildup, https://clubjazz.org/forum/index.php?topic=12119.0 this can bring the engine to misfiring.

It is a 1.5. Seems I’m not the only one going through this.
Cheers mate!

[TnTkr]

Now when you have been reading all the stuff, are you expriencing misfiring or just hesitation typical to 1.5 engine?

[Jazzmeister]

[/quote]
There is lots of information in Fitfreak-forums, but it's good to remember that they only have 1.5 liter engine in North-America. There are differences between GK Jazz 1.3 and 1.5 engines, although both are L-series DOHC i-VTEC engines. For example 1.3 uses Atkinson-cycle in low rpms but 1.5 not.
[/quote]
What is the Atkinson-cycle exactly?
Would it be in the 2012 1.3 engine?