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Hello all. I'd like a little help understand my fuel flow rate/injector pulse widths, and the associated settings in tunerstudio. There seems to be an odd jump in injector PW from ~7 to ~11 that occurs around 6000 RPM, that I would like help understanding specifically.
I grabbed a log in which I had a constant ~75% tps from 5-7k RPM, which you can see from 2.3s - 6s. As you can see, the injector PW jumps around 6k RPM. The odd thing to me, is that shouldn't my AFRs go much richer if I start flowing twice the amount of fuel? Interesting how they lean out in this instance. The MAP was not affected at this time.
Anyway I would appreciate any insight. Attached are the log in question, and my current tune in case that is helpful. The car was completely gutless up until 6k RPM, on the order of struggling to get up a hill, but from 6-7k was like hitting boost (the car is naturally aspirated and VVT is disabled). It was great and I want more of it. I first discovered this when I went to pass someone with fingers crossed on one lane rural highway. Decided to run the revs out and was left wondering WTF happened when the car magically had power around 6k RPM.
Your AFRs are a little all over the place, but they're 10-11s below 5500rpm, and you don't actually get to your 75% throttle until 5500rpm. You have a 150hp, maybe, stop being a ***** and smash the throttle. But typically any time your AFR error is -4.0, it's not going to run great.
Looking at your tune, your fuel table VE is going from 45 to 94 right at 6100, so that may have something to do with it to. That is quite possibly one of the worst fuel tables I've ever seen. Your spark table also screams "blow me up".
The spark table is pulled from the trubokitty base tune, apart from me reducing the timing advance near idle. I'm definitely hesitant to mess with it, and was planning on leaving that to the professionals. Unfortunately the dyno is booked through the fall, which doesn't last long where I am. What is a more appropriate safe timing range for a naturally aspirated application? What I'm able to do will likely have to stick until next summer. Although boost is planned for the future, that's definitely a distant future at this point.
I'm fully aware the VE table is a mess, and very much "in progress," but also that I don't really know what I'm doing, and I'm very much a learn by doing type of person. Not that I haven't spent way too many hours reading and watching videos. Not sure why I didn't see the bump in VE right where I was looking, though. I appreciate your advice there. I'll adjust and see how it feels.
I did see the TPS reading was not quite 100%. I very much am still a ***** behind the wheel, but normally am not afraid to use all of the pedal. I did go out and take some logs up a long hill at WOT to be sure that wasn't throwing things off, but they netted the exact same result. Made sure to check the TPS calibration as a sanity check as well.
Previous questions still apply, but as an update I went and started from square 1 again with the MSPNP base tune, and the results after 8 pulls up a hill are leading me in the same direction. The car wants a big bump in VE right around that 6k mark. Up until that point I run very rich, but if my VE numbers stay consistent I lean out significantly. Attached are the tune and log from my last run. To be clear I'm not happy with the point I left it, but the rain has come so I'm leaving it for a little bit.
Also, I pulled timing at the top end in response to your comment.
Not sure how to describe it, but it really feels like the cam profile or something is changing around 6k. Seriously sounds like it is hitting VTEC. This is a VVT engine, but the actuator harness is disconnected and the setting is disabled in the tune.
Is it a stock 01-05 intake manifold? I saw you’re controlling what appears to be a 99-00 VICs manifold, so if you’re not opening the 01-05 VCTS valves till 5500, you’ll get exactly your symptoms.
take that RPM in the programmable outputs and set it to 5rpm instead of 5500. I think it was injector I?
I think you might have it. I reverted the VE table to the base map again, and will go log some pulls as soon as I am able. Will report back.
The car is a 99 and I have a stock VVT swapped into it, including an 01+ manifold. So indeed VICs was likely enabled but not present. I never would have looked there so thank you for that.
Went from "my brother's prius has more power than this" to actually being pretty quick.
Although I've heard of other people having this problem before, I absolutely never would have found it on my own. Thank you very much for your help. Now that this completely invalidates all the tuning I've done up to this point, I've got some work to do.
I've attached a log if you're curious/bored of a 1st - 3rd pull.
Had you said it was a 99 with a 01 motor in it, I would have found it earlier. Solenoid is in exactly the same place, and is the exact same solenoid, so you wouldn’t have thought twice about plugging it in.
if you still have your 99 motor, put that intake manifold on for a decent bump in higher rpm power. And then you can properly control VICs.
That's a good idea, I might try that. I bought the car just a few months ago after the previous owner added some viewing ports to their bottom end, so the original engine and head are scrap. I do however have the manifold et al from the 99 motor. Looking at how I have everything now, the VICs solenoid is plumbed and wired, since I used the 99's wiring harness with the necessary modifications to run the VVT engine.
08-23-2021, 02:32 PM
Understanding fuel flow rate N/A
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