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I have a good quality aftermarket fuel pressure regulator, and I can monitor the fuel pressure with my Haltech ecu.
Here is my current theory:
I was led to believe that the normal flow rate for these injectors is 230cc/minute. When I first had them serviced, they ran solvent through the injectors on the bench until they flowed close to that rate.
Widespread current thinking is that these injectors should flow at 265 cc/ minute. So they may have still been a little clogged when I first tuned the car. Fast forward two years and lots of track days, the injectors have cleaned themselves out so that they flow a lot better, causing a rich condition.
I'm going to reinstall them, adjust my fuel map, and see how it runs. If it runs a lot better, I will install a new o2 sensor and check my air/fuel ratio at higher rpms compared to the target table.
I don't have time to aquire new injectors before Thursday's track event.
thanks again for everyone's input

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book 4AGE build, Supra W58 transmission, Corolla GTS live axle

9 out 10 fuel pumps, out of the box, will go A LOT higher than the spec for the injector PSI. Verify that the low and high vacuum functions of the FPR, is reducing line pressure. The vacuum comes into play at low RPM low load, high vacuum to reduce fuel pressure. If the FPR is proven to have taken a $hit, I would look into the option of an adjustable unit that can be set near the factory PSI for your injectors.

Thanks for the reply Dave. I do have a good quality aftermarket adjustable fuel pressure regulator. Static, the fuel pressure is set to 45 psi. At idle, it drops to about 40, going higher and higher with more throttle.
I am not concerned that my vacuum at idle is only 10. It's due to a combination of agressive cams and independant throttle bodies. I have tested for vacuum leaks. Also, the vacuum goes to -17" when decelerating. These Denso injectors are made to run at 45 psi, so that's where I got the target from.

I'll know in a day or two if tweaking the fuel map has made any improvement or not.

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book 4AGE build, Supra W58 transmission, Corolla GTS live axle

Those (tan) injectors should average around 268cc at 43.5psi. They are perfectly fine to run at that pressure, you'll just need to accommodate with your tune. I have a set of four that I just pulled off my car that I'll make you a smokin deal on if you're interested in an extra set. They're about a year old with roughly 2400 miles on them.

I'm curious, you said your ECU monitors fuel pressure. Is it just for datalogging purposes or is the ECU making adjustments on that input?

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Regards, Ron

Hi Ron
I might take you up on your injectors, let's see how it goes when I get the car on the road again.

I added a fuel pressure sensor to the car when I first went from bike carbs to fuel injection. The car would start, then die right away. Turned out that the ecu did not turn the fuel pump on soon enough after starting to keep running. Haltech never did figure it why. I gave up on them, it's a long way from Canada to Australia. I just went back to energizing the fuel pump relay when the ignition is on, and it ran perfectly.

The ecu doen't use the data from the fuel pressure for anything.
cheers
Doug

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book 4AGE build, Supra W58 transmission, Corolla GTS live axle

I would advise against adjusting any fuel trims without having an operational wideband hooked up.

I trimmed the fuel by 25%, installed a new o2 sensor for the wideband.
The car still runs rich, especially at certain part throttle conditions. Rather than just tuning, it think I will replace the injectors first.
I just have to decide if I want the exact same ones, or go for some newer technology.

The good news is that I made it to my track event last night, and I ran pretty well, and my misfire is finally gone.
thanks everyone for your input.

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book 4AGE build, Supra W58 transmission, Corolla GTS live axle