LSJ injectors in the "untunable" 2.2? - GM Performance Tuning

bc3tech · #1 (**permalink**) 03-29-2007, 03:36 PM

A'ight guys I just tried to put the LSJ Injectors in my 2.2L Ion (untunable e16a ECM) and had mixed results.

During the process i unplugged the battery and when all was done and injectors were verified leak-free I started the car. Obviously idle was rough but eventually long term trim took over and got my idle to 14.7:1.

The problem I have is when i get out on the road. 1st gear is fine, then i shift into second and the ECM is just dumping fuel into the chamber. It's caused a p0300 (random piston misfire) the few times I've tried it and i ended up w/ absolutely drenched plugs.

I'm wondering if anybody's done this successfully in the 2.2L ion w/ minimal (if any) tuning? I've got the SAFC but of course it can't do anything in closed loop. Once I got WOT on the car and the plugs get cleaned off by the leaner mixture, she shapes up as the SAFC starts to run things.

the ECM on these things seems VERY intelligent... I just think i'm in a catch 22. I think the long-term trim would learn where it needs to be if i drove the car around, but i can'd drive the car around cuz the trim's wrong and soaks the plugs :(

i'm watching the short & long trim and it's not hitting the long trim's limit (at idle long trim is -21.9% and short is -47.8%) so it can definitely handle them...
i am wondering if anybody's got a solution that'd work? I used the unplugging of the battery in conjunction w/ resetting the fuel trims via my DashHawk unit to set everything back to 0%. As stated earlier the car learned its idle spot pretty quickly - the problem seems to be getting it to learn driving spots w/o soaking the injectors and resulting in misfiring :(

Any input would be very welcome.

Nels996 · #2 (**permalink**) 03-29-2007, 07:47 PM

What size are the injectors? Did you install a power adder?

Nels

bc3tech · #3 (**permalink**) 03-30-2007, 09:28 AM

injectors are 32#

I have a procharger c-1 pushing 10psi on the engine. intercooled.

the setup was doing well but fuel was not as manageable as i'd have liked it to have been so i put an SAFC on the engine and found out quickly that using an AFC to control the injectors was only so good, as the injectors were maxing out. so larger injectors were in order, however, as you can see they caused problems.

prior to the SAFC, i was using a DFMU w/ external fuel pump to just increase the fuel pressure in the rail so the injectors wouldn't increase their duty cycle, however this method was less than precise for optimal performance.

Matt95GT · #4 (**permalink**) 03-30-2007, 01:14 PM

How much bigger than stock are those LSJ injectors?

Bigger injectors + FMU + S-AFC works well, but only if injectors aren't huge compared to the stock ones. The S-AFCII on my Quad 4 has been working quite well for tuning. I initially had your problem with just the larger injectors and FMU (Cartech/BEGI adjustable FMU). Did you remove your FMU once installing the S-AFC?

Nels996 · #5 (**permalink**) 03-30-2007, 03:46 PM

I believe that the 2.2L code F engine in your Ion has a MAF sensor. Did you have the MAF rescaled? You state that your system is producing 10psi. What is the CFM of your compressor? You need to data log your MAF voltage as well volume, and look at your readings. The problem that you may have is that, there is more air being drawn through the MAF at idle and the PCM thinks you are at part throttle. I had a similar problem when I was tuning my car.

Nels

Matt95GT · #6 (**permalink**) 03-30-2007, 04:03 PM

^Ahh... I keep forgetting the ecotecs aren't speed-density only. In that case, yes the MAF will complicate things.

bc3tech · #7 (**permalink**) 03-30-2007, 04:13 PM

Quote:

Originally Posted by Matt95GT

How much bigger than stock are those LSJ injectors?

Bigger injectors + FMU + S-AFC works well, but only if injectors aren't huge compared to the stock ones. The S-AFCII on my Quad 4 has been working quite well for tuning. I initially had your problem with just the larger injectors and FMU (Cartech/BEGI adjustable FMU). Did you remove your FMU once installing the S-AFC?

i disconnected the DFMU, yes... the problem i seemed to have is that the long term fuel trim was set for the 24# injectors, and wasn't adjusting "fast enough" when it was learning as i drove. it would stay at its old value, and drench the plugs before it got a chance to learn NOT to do that!
i disconnected the battery and reset the fuel trim w/ my Dashhawk unit, and that didn't help. the fuel trim on the 24's was about -4 to -5%, while once reset it was at 0%, even richer... so yeah.

Quote:

Originally Posted by Nels996

I believe that the 2.2L code F engine in your Ion has a MAF sensor. Did you have the MAF rescaled? You state that your system is producing 10psi. What is the CFM of your compressor? You need to data log your MAF voltage as well volume, and look at your readings. The problem that you may have is that, there is more air being drawn through the MAF at idle and the PCM thinks you are at part throttle. I had a similar problem when I was tuning my car.

Nels

The 2004 Ion 2.2L L61 engine has a MAP sensor - speed-density.

Quote:

Originally Posted by Matt95GT

^Ahh... I keep forgetting the ecotecs aren't speed-density only. In that case, yes the MAF will complicate things.

see above.