Missing Injector Data

Hi All,

I am just about to do an ECU swap to a Link G4+ plugin on my Evo 8MR. I have hit a bit of a hurdle with my injectors.

DISCLAIMER: I am very green so dont assume anything. ;)

I got the car second-hand last year and it has a set of FIC1050 Low-Z injectors (FIC-IS126-1050) in it. The problem I am facing, is that going to the new ECU, I have absolutely no data on the injectors such as dead time, voltage offsets, etc.. These injectors, from what I have read, initially came with a data sheet but that has been lost to the ages and was not given to me.

My question to the board is, what kind of values do I use when configuring the ECU when I have no data on the injectors?! I am sure that I am not the first person thats had to tune a car with no injector data other than flow rate, but because its my first time down the rabbit hole I dont know how to approach it. Asking for some more seasoned experience (or for someone to pull a white rabbit and have the data sheet for the same kind of injectors sitting around).

Cheers

You could try emailing FIC with the serial number of the injectors and see if they can dig up the data. They should at least be able to give you a starting point.

In the absence of that you can follow a logical method to dial then in. I put the ECU in open loop and usually start with a smaller injector size than what I know or think them to be. Dont worry if it idles rich as long as it is not ridiculously rich. Set your boost low and carry it into boost and see how the AFRs match the AFR table in the ECU. Adjust your injector size until you get a good match. Then go back to the low load areas and adjust the latency until your low load AFRs are a good match also. Latencies have significant effect at low injector pulse widths and very little effect at high pulse widths (because for a given battery voltage the latency is a fixed pulse width value so it will be a significant contributor to the total pulse width at low load and only contribute a small percent at high loads where the fuel demand is high).

You may then need to tweak your VE table a bit also. You can then re-enable closed loop and you will be good.

Hope you can follow what I have said.

Hi HS Engineering,

Thanks very much for your post! For the record, I did get onto FIC and they were very helpful and provided me with some data for my injectors very quickly. Definitely impressed with their customer service.

With that said, I dont want to diminish your assistance. This is the kind of strategy that doesn't come to mind as a newbie to this stuff. It sounds like a great way of going about it when you have nothing to work with which will no doubt come up sometime in the future for me. Your post has been incredibly helpful and educational.

Cheers!