FBO Coupe Breaks Up Around 3200RPM

[NoKz]

More than likely. My s.trim was doing the same thing in my logs while driving especially at super light throttle. Very little throttle tip in at high vacuum. Thought it was something to do with rev hang/fuel overrun settings but always felt it was not right because it only happened toward the end of 20k miles. Turned out my injectors were progressively failing. There is a "reduction" that is applied normally in this area by the computer....when it cant reduce enough directly it has no choice once the rich mixture hits the o2s the trim will react. If you have access to try I would see if an induction service makes any improvement (i doubt it but would be something to try).

edit: actually my step one if it was my car would be straight 93 with a new tune file and see if there are any changes. ethanol can cause black goo/tar buildup in the tip of the injector with heavy use (sugar in the ethanol falls out of suspension at the tip of the injector when exposed to the heat allegedly). This is normally resolved as soon as pump gas is applied to this goo it usually dissolves. Like if you had an injector held in your hand that had this issue and dipped the tip in a small jar of 93 it would almost instantly dissolve to brand new condition....that's how "reactive" it is.

Funny you mention that; my car is around 28K right now. Since the issue started, I've only ran 91 with the hopes of clearing any blockages. However, the problem still persists. I'm probably going to swap injectors with my wife and see how that goes. Did you end up replacing yours?

E85 seems to be a culprit in some of these injector issues, no?

Yeah. However, my buddy works at Honda and they've been replacing injectors on stock Accords and Civics due to failing issues. So it could be a combination of both.

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[PowerPerLiter]

E85 seems to be a culprit in some of these injector issues, no?

More often than not although there are also alot of reported cases with factory cars at the dealer level as the op mentioned. Mine was coincidentally within a week of converting my "powerperliter" map over to an e20 and e30 map.

 

[PowerPerLiter]

Funny you mention that; my car is around 28K right now. Since the issue started, I've only ran 91 with the hopes of clearing any blockages. However, the problem still persists. I'm probably going to swap injectors with my wife and see how that goes. Did you end up replacing yours?


Yeah. However, my buddy works at Honda and they've been replacing injectors on stock Accords and Civics due to failing issues. So it could be a combination of both.

Haha yup right at that mileage. I ended up trading the car in early with the issue and got my '20 (I was at liberty to with my connections). The tech that worked on it to certify it kept me in the loop and ultimately replaced the injectors and went on the lot. Sold about a week later. The injectors were visably clogged with shit on cylinder 2-3 (3 being the worst....which looking at your logs looks to be your most misfired cylinder.....

I will see if I can find the picture he sent me.

This is where I think the "tuning abilities" we have over the cars exacerbate or create this problem. All the rev hang settings etc are timed and created to avoid carbon buildup along with the engineers other reasoning. Hondata ( I say them specifically cause I dont know if this is the same with ktuner) also does not do anything by default with the fuel overrun injector timing when you "disable rev hang".....this prevents the throttle plate movement but leaves the injectors on the same amount of time as stock while the throttle blade is closed. I asked about if we should lower the fuel overrun settings when disabling rev hang and the answer I received was "you can if you want to". Common sense would tell most people long term this can create multiple issues (cat damage, carbon buildup etc)......just like all this advanced vsa stuff....reducing timing like it does will add to carbon and egt rise. They say the advanced vsa works so quickly that this is not the case. I call bull. You cant tell me one of these cars on street tires with the power to "need" advanced vsa will not be in timing reduction at least through the first 2 gears. Think of how many combustion events are happening in that time with way too low timing. Especially as sensitive as these cars are to timing changes.

They know these things but let the uneducated find out on their own.

MoAR FeAtUrEs PLeaSE!!!!

 

[PowerPerLiter]

edit: of course all this is assuming it is the injectors.

I also want to add because in this case our cars/symptoms were so similar; moving forward I would altogether avoid the long warm up. I did this too as I have always been so overly anal about making sure the car is significantly warmer than dead cold. I will not or have not waited with my new car anywhere near as long. As soon as the idle touches 1200 or less I am driving. I suspect long idle time during warm up added to the issue I had.

 

[Hollywoo0220]

With a Catless DP you ALWAYS want a custom tune.

 

[JO3L]

You said you put in new plugs, but did you close the gap on them?

When running more boost than stock you want the gap to be around 0.026-0.028".

 

[Hollywoo0220]

You said you put in new plugs, but did you close the gap on them?

When running more boost than stock you want the gap to be around 0.026-0.028".

That's really not going to make or break a Stage 2 or TSP tune.
What he has is a "Catless DP" and he is more likely creating boost creep and restricting the Electronic WG.

 

[gtman]

Common sense would tell most people long term this can create multiple issues (cat damage, carbon buildup etc)......just like all this advanced vsa stuff....reducing timing like it does will add to carbon and egt rise. They say the advanced vsa works so quickly that this is not the case. I call bullshit. You cant tell me one of these cars on street tires with the power to "need" advanced vsa will not be in timing reduction at least through the first 2 gears. Think of how many combustion events are happening in that time with way too low timing. Especially as sensitive as these cars are to timing changes.

Which is honestly why I haven't even tried Advanced VSA. JR says "it could be a problem (the timing retard) if used too often". "Too often" being a little too vague for me. Plus the stock tires suck and I drive in rain and snow. I control my traction with my foot.

 

[Hollywoo0220]

Which is honestly why I haven't even tried Advanced VSA. JR says "it could be a problem (the timing retard) if used too often". "Too often" being a little too vague for me. Plus the stock tires suck and I drive in rain and snow. I control my traction with my foot.

If you select the "Light Ignition Pullback"; shouldn't have any issues.

 

[shibles]

You said you put in new plugs, but did you close the gap on them?

When running more boost than stock you want the gap to be around 0.026-0.028".

Source? Just curious, I haven't heard of adjusting spark when altering boost and thus have not done so.

 

[PowerPerLiter]

That could be all it is...I had assumed with the ethanol use that the op had done this already especially if they had them out.

Maybe a super easy fix then!

 

[PowerPerLiter]

Can't hurt to try it anyway. Ethanol puts an increased load on all ignition systems and that is the first resolve usually for most.

 

[shibles]

Again I shall ask, when are we getting some freaking aftermarket injector options for Si??? I've been teetering the last few months between waiting for injector options or removing flex fuel and getting PRL Cobra CAI Race MAF + TSP Stage 1 tune for it (only been running 93 octane for a long while now)

 

[REBELXSi]

I have no productive information to provide but I just want to say how funny it is to specify that it's a coupe

 

[JO3L]

@shibles

Source PRL

https://www.civicx.com/threads/lets-talk-spark-plugs.38367/#post-638001

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