K24A Extremely Rich

[MK2MR2]

93 MR2
K24A w/Borg Warner S252 Turbo
1000cc Injectors / FPR @ 50psi
GM 4Bar MAP
KProV4
Dyno'd 11/1/18 - 334/300 @ 10psi

The issue is that it is running WAY too rich at idle and low RPM. It was pretty rich when it was tuned, for safety, but it's gotten ridiculously richer. AFRs are deep in the 9s at idle, absolutely killing my mileage and literally pouring fuel out of the exhaust. The only change I made to the car after the dyno was the fuel tank...went from stock tank to fuel cell, pump and pressure remained the same; nothing else was changed.

My tuner is not available for a few more weeks, but wanted to post the calibration to see if maybe there is a more obvious problem with the fueling at idle. I will get it properly re-tuned soon, but in this shape the car fouls plugs faster than I can drive the car to him. Any help would be greatly appreciated.

[Spunkster]

Without the a datalog showing the issue it is hard to say what might be happening.

[Hondata]

Injector dead times are for 310cc injectors not 1000cc injectors, so a minor change in temperature or voltage is going to throw off the fuel at low openings.

[MK2MR2]

Injector dead times are for 310cc injectors not 1000cc injectors, so a minor change in temperature or voltage is going to throw off the fuel at low openings.

Really? Hmmm I input the dead times for the injectors I got according to voltage. That's how it's always been too.

[Hondata]

Dead times in your calibration are 1ms @ 14V, whereas 1000cc injectors are close to 1.2ms at that voltage.

[MK2MR2]

That is interesting. Going to check this out today and maybe shoot the injector vendor a message about these dead times.

[MK2MR2]

Ok so I got the attached sheet for the dead times, although they match what I have in there now. Is this just bad data altogether?

Also, checked my FPR and reset base pressure to 43 and that helped some...still sits around 10.5 at idle though.

[Hondata]

First check your voltage is stable before doing anything else.

What injectors are these? Some manufactures use electrical testing to determine the dead times rather than empirical testing, so the times are too low. Probably the ID1000 will work for you, but if you change the dead times you'll have to re-tune.

[MK2MR2]

That's a good idea, will check voltage to each one today.

These are from a local Vegas racing company, DIYTuning702. Guess deciding to support a local business kinda bit me in the ass :/

The fuel pressure decrease and some adjustments to the dead times might be enough to get it to my tuner in a few weeks.

[MK2MR2]

Just a follow up.

Injectors and their voltage checks out, dead times were cleared and reset to what the manufacturer recommended.

Car still runs pig rich, reduced overall fuel trim from 30% to 10% and it did help some. I managed to fix the Analog Input from the AFR gauge as well, I grounded it to the ECU's Analog ground versus the one I was using before...the response time on the ECU to match what the gauge reads is a tiny bit off. If I had to guess, maybe 1/3 of a second, but it does read really close. (ie. Gauge reads 10.5, ECU reads 10.45/10.55)

So now I can datalog with pretty accurate AFR readings. I will retune the car soon and post up my findings again.

[Hondata]

I'm not sure I was clear earlier; if the manufacturer supplied dead times are not around 1.2ms @ 14v then they are not going to work well.