Good luck with the tuning , though complicated .....the 2.4 PCM sounds interesting to play with once all the tables are accessible .

 

You guys should of asked him if he ended up recalibrating the MAF, I bet its not only out of cal, but being run out of range.

I couldn't make it today, I got stuck in Willard in a hotel, won't be back till tomorrow, but if you guys need any help, you all have my number.

 

Check with boostedsol from the solsticeforums. He's used the LS2 to edit his turbo set-up, althought he's running an extra set of injectors so that might not help much with the fueling problems since you just went with bigger injectors.

 

thats a good point, maybe on the next tuning session you could come with us and see whats up

also, my installer couldnt seem to locate and 2 step colder plugs for me to run, would any of you know exactly what plugs work for the 2.4 that would be 2 steps colder

 

I assumed plugs for the 2.0 would work with the 2.4. But assuming isnt always right.

 

Al..I was voicing my opinion on the MAF too. Tuner dismissed it right away. I still think its a MAF related issue. Gotta be!

 

Not bad, not bad... should be pretty quick once you get the lean issue ironed out. I'm interested to see what kind of quarter-mile times it turns, keep us posted on when you plan on going to PRP this summer.

 

well if this is solved by the 22nd ill be racing that day

got my cel codes read here they go:

P0121
The PCM has determined that the actual input from the
throttle position sensor does not match the calculated
input for the throttle position sensor derived from
the input gathered from the other sensors ie: manifold
absolute pressure sensor, idle air control motor
position, ECT.


P0172
The PCM has determined that dring testing, the fuel
system for bank 1 was too rich. (Bank 1 identifies the
location of cylinder #1, while bank 2 identifies the
cylinders on the opposite bank)

also, i wanna report that my coolant temps are up by about 5 degrees into 203 even though i am staying in vacuum

 

how did you run the maf? pull through or blow through



You'll never be faster than the ss/sc




that was just a joke people to keep you on your toes

 

maf is before the turbo

 

Pull through... MAF sensor is before the turbo.

I got the joke.

 

good job Celica, you make me proud.

 

man, it always takes someone to lead the pack, and thats what ur doin! once u get these issues figured out, u'll have **** loads of fun, you have some very big ***** to take this on!!!.......good luck! i cant wait to see this finished

 

See above.

My 2.4 on the dyno shows that same drop in HP and torque at 3750, then a sharper rise in both than before the drop. I don't think your lean spike is causing the drop, I think the drop is causing the lean spike. The reason I say that is because mine doesn't exhibit that lean spike, but does show that drop at 3750. We assume that 3750 is the switch point for the cam. As the cam advances, there is some drop in HP and torque as overlap goes up, and then it picks up better than before as the revs rise. I think GM may have put the switch point just a hair early, or it's done on purpose so the switch doesn't cause a HP spike if switched later.

Anyway, bottom line is that stock 2.4's show this little dip at 3750. What it doesn't show is that earlier spike, which I assume is where boost comes up. It would be beneficial to add a plot line for boost to this so you can see if boost rise is causing the lean spike.

Keep it in mind as you tune.

Are you monitoring the knock sensor? If you're not getting knock retard, then it might not be too lean (but it looks REALLY close!).

 

The first code is gonna have to be disabled, your VE table isn't setup to see boost, and won't be able to until cam phasing can be locked and logged. The p0172 code is because the MAF is out of calibration.

 

that is sweet, good luck with tuning

 

dude im so impress have fun!!!!!!!

 

i can't wait to see the end result of this! i've been waiting for someone to do this to their 2.4, considering i have one as well

(don't let the sig fool ya... i'm ss/na)

 

then fix your sig! its soo misleading...

 

I agree..I also didn't hear a vac leak. But that doesn't mean anything my ears are shot.

 

MAF, or MAP? If MAF, then is it because of too much air flow? I could understand MAP being out of cal under boost, since it will swing over to positive.

I don't see how cam phasing will have any effect on any of the parameters that need to be logged/changed for boost (namely, fuel flow and ignition retard).

 

Cobalt PCMs fuel exclusively from the MAF readings and only use MAP for correlation checks and MAF failure.

Because the VE table is based partly on cam phasing, changing any values would be always incorrect since cam phasing will always occur as preset values that cannot be changed or even logged.

 

I strongly agree with witt on this. you need someone to calibrate the maf and then tune your PE... i hate to say it but the guy you had to tune doesnt seem like the best choice...

as for the codes, dont freak out those are typical codes you'll need to disable. your only boosting 10psi, you shouldnt need to replace the map.

It does suprise me tho that the maf is on the turbo inlet, just changing to this location alone will require alot of maf calibrations. just find someone with hpt-EIO and a wideband... these issues are simple to fix.

 

Thanks!

I always learn from your answers - that's why I ask!

Are you suggesting putting the MAF between the turbo and the throttle body (in the pressurized intake stream)?

 

I'm learning about them just as much as anyone, I just benefit from the fact that I have redline dan (djt81185) and a few others (WSFrazier, PpAzZ1101, etc) as drinking buddies as they are tuning geniouses.

Edit: My opinion on putting the MAF after the turbo (blow through) may be one way to get around having to upgrade to a larger MAF, but will detract from the sensor's precision. all imo tho.