Bad Idle after Injector Change

[TheStigP11GT]

I have built a brand new SR20VEN1 build, I have now ran in the engine using a Map from the old engine, and increased the fuelling throughout the rev range to bring the AFR's between 12-13:1. The map ran 333cc Side Feed Injectors. and I had the engine running good although it did drink the fuel, but I know it does need a remap - I just do the base map to make it safe.

I have installed a set of 370cc Deatschwerks Injectors. I went through the suggestions that it shows on the guides by resizing the Injectors. When this was done, I burned the changes, and the Started the car. The engine felt like it was badly misfiring, and AFR's showed as over 20:1 AFR's. I then re-uploaded the previous map and the engine started but AFR's were around 10:1. I changed the KCONSTANT to 300cc and AFR:s show around 13:1, I was able to adjust the fuelling and make the AFR's around 12-13:1. the main issue I have now is that the engine idles at around 1300-1700RPM which is too high for idle. Changing fuelling values and timing have no affect, I then changed the Latency from 600 (which it showed) to 1200, idles dropped by around 100 RPM, (including changing fuelling).

Nothing else was changed except the Injectors, so I am at a loss to what else to do. Any ideas?

I have another few modifications to do before remap, so professional remap wont be done till next year, but I want to at least make the car a little drivable.

[Matt]

I'm hoping you only adjusted the injector size once and then fine tuned with the injection multiplier afterwards?

If not then start over again with the factory maps, do the injector resize and then fine tune injection multliplier. Your other problem is that DW are drilled out injectors so they will never have the same spray pattern as a decent set of injectors