Hello!

I have an Opel Astra J with the A16LET engine being controlled by the DELCO E83 ECU. I recently fitted larger Bosch injectors (395 cc vs the stock 310 cc) and successfully scaled them using WinOLS software. My trims at idle are (-1.76 to 0) and constant 0 at part throttle. However, my main issue is power enrichment, I can't seem to get my desired equivalence ratio. Any mods I do to the power enrichment table I end up either 0.64 or 0.69. I managed to get 0.76, through fiddling with what is called "indicated peak torque" table, but it's still a bit rich at 11.1 AFR. Goes down to 10.7 at 5500 RPM. I would like to know if there is anyone with experience as to what this engine like to see regarding AFR, I am shooting towards 0.78-0.80 equivalence ratio, and how to exactly reach this target.

Furthermore, the values in WinOLS is very confusing, PE table has values of 1147 and I modified it to 1247 to get my 0.76 Eq. ratio, however any value else I get back to 0.64-0.69. And it is not 1.147 as in 14.7/1.147= 12.81 AFR, because 1247 gave me LEANER AFR value and higher eq. ratio of course.

Indicated peak torque table has values that are large, like 700 at low rpm and 1475 at 5850.

Any help?

Any chance it read leaner due to rich misfiring? What happens if you change the 1147 to about 1111? Does it get about 3% leaner?

Eq ratio is the inverse of Lambda. Larger Eq ratios are richer, and Larger Lambda values are leaner. So an Eq ratio of 1.11 is about Lambda 0.90. A good target EQ ratio is about 1.11 to 1.14 for max power. The targets you describe (0.78 - 0.80) seem like rich Lambda values - Eq would be 1.28 - 1.25 for those lambda values.

You also throw in AFR. The Air-Fuel Ratio will be leaner with larger values (like Lambda).

Dear David, Appreciate your helpful response.

The AFR at 1147 PE gave me 9.4. Which corresponds to 0.64 Eq. ratio, logged by the diagnostic scanner. So, 0.64 X 14.7 = 9.4 AFR. However, when I changed it to 1247**,** AFR is now 11.1 which corresponds to 0.76 Eq. ratio.

I haven't tried to reduce the number as at the very beginning of the PE table, first 4 coloumn are a constant values of 1024 then it increases to 1147 and remain constant over the entire range.

Do you reccomend I reduce the PE from 1247 to 1111? I'm afraid it may go even richer and register 8.8 AFR.

To be clear, and AFR of 9.4 is a Lambda value of 0.64 (for Gasoline 9.4/14.7), and an Eq Ratio of 1.56 (for Gasoline 14.7/9.4). All of these are very rich values, and i would expect to see black smoke from the tail pipe when running this rich.

Yes, I recommend you change it by at least 5% (so 1184 or less) and see what happens.

Great. I will adjust my PE table with a value of 1184 and log the AFR.

For this engine, do you recommend an AFR vaue of 11.5? Or higher or lower?

Okay. Changed the PE table to 1184 and to my surprise nothing seems to change the commanded Lambda of 0.76. No matter what I do with the PE table, lambda 0.76 is always what is commanded. Seems like it is locked or something.

My commanded lambdas I have managed to get before were 0.64, 0.69 and 0.76. All of them are not what I desire. 0.78-0.8 is what I am aiming for as it is turbocharged.

What could possibly be wrong?