High deadtime, What is going on?
 

I recently moved from a set of the RX-7 injectors to a new set of yellow top RX-8 injectors (460cc to 435cc)

Am doing the procedure where you switch between "Squirts Per Engine Cycle" from 2 to 4 back and forth until the AF ratio is the same, holding it at 4k rpm to make sure the injectors are not in their low speed non-linier zone

I had this same thing with the RX7 injectors too, but the deadtime needed is almost double what I see other people running

I have seen Braineack running 1.2 with the RX7 injectors I was getting 1.7ms using the above method

With these new RX-8 injectors, this thread suggested 0.75, but I am getting 2.0 with the above squirt be engine cycle method.

It is making it so I get to use the entire resolution of my fuel table, am idling in the single digits, have to do a couple more bits of math to find the needed Req Fuel to let it go up to 230 or so on the fuel table now though, but car is running fine, just I am wondering if anyone has any idea on why I am getting double+ on my deadtimes

I thought rx8 injectors were 550cc, or was that the rx7 turbo injectors?

.75 is ridiculous for an ev6 and certainly incorrect.

Many rx8 injectors are counterfeit and don't flow what they are supposed to flow.

Yellow RX8 are 425. 0.9 to 1.2mS is the general range of dead times. My actual setting was .85, which I admit was on the low side. I think I had some Non-linearity correction on top of that, however. Low end nonlinearity is severe, but difficult to dial in, at least it was for me. Changes so much with heat soak (hot re-start), that, in the end, you have to accommodate with EGO anyway.

2.0 is too much. IIRC, my car idled at about 1.83 total on time with those injectors, so you will never get there. This was for 14.7 AFR.

Honestly, going 4 squirts with those injectors is not advisable. Are you trying to get EAE to work? You can do it with 2 squirts.

No, was just using the procedure to change from 2 to 4 squirts and adjust the injector deadtimes watching the AFRatio until when you change between the two it stays the same. This was my understanding on how to fine tune and find the deadtime on injector if you do not have an oscilloscope or a way to test them outside the car.

When done, yeah, it is set to 2 squirts, but my entire issue is that in doing this, both for the new RX8 injectors and the older RX7 injectors, my deadtimes seem to be double what anyone else has gotten for both types.

Brain was getting 1.2 for their RX7 injectors, I was getting 1.7

Other page says that the new RX8 ones were 1.0, I am getting 2.0

Car is running ok, I am just purplexed why why these are so far off.

I am almost wondering, since this is a Rev built ECU, and since I broke a pin on the ECU and had to buy a new one when I had taken it apart to change to a different MAP sensor to add in barometric correction, he still never game me his unit specific proprietary code for it, and is a side effect.

i dont think 1.2ms was correct. for those injectors 1.6-1.7ms seems more accurate.

rx8 injectors should be closer to 1.2ms.