Fuel Trims with 550 inject and a revtronix stage 2

[LucyFord]

Hey guys,

I have been searching the forum and can't find my answer.

What should my long term fuel trims look like with 550 injectors and a rectronix stage 2 chip?

Currently they're all around +12%. At the time i thought this was just due to the 550s. But I noticed a hesitation after shifting during heavy throttle maneuvers and now think there might some unmetered air (ie leak pre turbo) getting in, that or my BPV is leaking.


Thanks!

[LucyFord]

Now that i think about it....+15% doesnt make sense for larger injectors. -15% would....

[Legacy777]

Is the stage 2 chip supposed to use the 550's?

What are your AFR's like?

[LucyFord]

I believe that the stage 2 is suppose to use 550s..


I dont have a wide band so i cannot share AFRs. Though if i did I would much rather give it to you in equivalence ratio

[BSOD2600]

Stage 2 chips could use 440cc, 550cc, or whatever the original owner specified in the order. Assuming 550cc is a bad idea (for example I got mine with 440cc). There is no way to check what it was tuned for either. There is no way to check what revision of a chip you have.

Scan through http://bbs.legacycentral.org/viewtopic.php?f=19&t=43958. The Stage2 v3 chip increased the fuel trim learning limits. I forget what % they max out on without that feature, but I think it was +14.8/-25%. The closer the trims are to 0%, that means the ECU is closer to the tuned specs for the specified injector flow rate. The further the numbers increase/decrease, means the ECU has had to learn and compensate.

[ciper]

Did you use the wrong MAF?

[LucyFord]

I must have been sleep deprived when i read those fuel trim numbers because they are only 3%. I confirmed my chip is for the 550s and I am running JECS MAF..

I did set a 49 MAF code but i am not sure how. I cleared it and it hasn't came back (which is scary because i know it will at the worst time possible).