Hi everyone, I’m having trouble with my RX-8 192hp (4-port) after replacing all injectors (primary and secondary) with OEM Denso 540cc “blue” injectors – the same ones that are normally used as secondaries.
Here’s what I did and what’s happening:
My setup:
Engine: RX-8 192HP 4-port
Injectors: 4x Denso 195500-4450 (blue), approximately 540cc @ 3 bar (~626cc @ 4 bar)
What I’ve already done:
• Set Injector Scaling to 626
• Copied Injector Latency 2 to Injector Latency 1 (so both are using OEM Denso latency values)
• Reduced Cranking Injection Pulsewidth by about 50 percent
• AFR base set to 0.98 for open loop starting
• Closed loop is active (still enabled)
The problem:
Even with these changes, the car cranks but doesn’t want to start without throttle.
Fuel injection pulse width reaches 18–21 milliseconds during cranking.
AFR drops to around 9.0 or even lower.
Once it starts, it runs very rich for a while.
My questions:
1. Why is the ECU still injecting so much fuel despite reduced cranking pulsewidth and correct scaling/latency?
2. Could there be hidden enrichments like “Startup Enrichment” or “Warmup Fuel Correction” that need to be reduced?
3. Should I delay closed loop activation (O2 feedback) to prevent over-correction?
4. Could voltage compensation in latency be wrong? The battery drops to around 10.8V during cranking.
Any help would be appreciated. I can provide logs, screenshots, or tables if needed.
Thanks in advance.