4.8L cos3 w/ 4l60e in Toyota. having trans pressure issues via the tune

[stroker97k1500]

Hello

I put a 4.8L LSX with 4l60e non Maf cos3 SD tune with 0411 ecm and i have the truck running pretty well except I have an issue with the pressure control solenoid not keeping pressure up (more amperage to solenoid) via the tune and causing slippage until something in the tune maxes out the psi to 90 and slippage stops. I have changed everything i know to stop this from happening but it still happens. I am clearly looking at something incorrectly. Btw the trans is newly overhauled with most all sonnax parts and Precision TC with 150 miles on it.
if anyone would care to offer suggestions I would GREATLY appreciate it.
My tune and the log is attached to this message also.
Thanks in advance
Robby

[joecar]

I'm looking thru your files...

[stroker97k1500]

Thank you Joe

[joecar]

Also log the pid GM.TRQENG.

[joecar]

Also fix this:


EFILive Custom Calibrations
{A0002} Octane Scaler Limiter, was out of range when loaded.

Set it to 99%, save file, exit, reopen tunetool, set it to 100%.

Also fix A0012, A0013 the same way.

[joecar]

Are you running with boost...?

I think your IFR is wrong... trucks usually have manifold referenced FPR, and your IFR table is sloped (i.e. for un-referenced FPR).

( BTW: if you are running boost, your IFR table is for very small injectors )


if your IFR is too low, then the VE table will have been tuned low, this causes the calculated engine torque to be low, this causes commanded PCS pressure to be low

( you're in SD, so airmass calculation will be from VE, and airmass calculation is one of the inputs into the engine torque calculation ).


( BTW: with a COS, the HO/LO adaptive spark still works, so you can make your LO lower for safety )

[joecar]

As an experiment, increase both IFR and VE by 30% and see what happens.

[stroker97k1500]

Are you running with boost...?

I think your IFR is wrong... trucks usually have manifold referenced FPR, and your IFR table is sloped (i.e. for un-referenced FPR).

( BTW: if you are running boost, your IFR table is for very small injectors )


if your IFR is too low, then the VE table will have been tuned low, this causes the calculated engine torque to be low, this causes commanded PCS pressure to be low

( you're in SD, so airmass calculation will be from VE, and airmass calculation is one of the inputs into the engine torque calculation ).


( BTW: with a COS, the HO/LO adaptive spark still works, so you can make your LO lower for safety )

I do appreciate you looking through my tune. I havent had the opportunity to log the truck again since i havent been home to do it yet.
I am using an ls1 intake manifold with the truck injectors and the ls1 fuel rail cut down and re welded to fit. I am also using the corvette fuel filter with internal presssure regulator and zero boost and the speed density tune (no MAF). I used my best guess as to the fuel flow and I

[joecar]

Ok, then sloped IFR is ok for Corvette filter/FPR.

[stroker97k1500]

Ok, then sloped IFR is ok for Corvette filter/FPR.

I am hoping to get there tomorrow and do some logging to share back here. I did do one log from memory with the added pid you requested but it was already after the ECM commanded all the time 90psi to stop the slipping. I was wondering if anyone you know has a cos3 /4l60e tune where I can swap the trans segment and see what may or may not happen as well. If not I can try the 30% on ve and ifr tables to see what happens and also will log the torque pid from cold. I have another truck tune I can convert to cos3 and then try to swap the segment if you don't have one.
I'll post back tomorrow with a follow up
Thanks again
Robby

[stroker97k1500]

I happened to come back across this post from a while back. The whole issue was the new trans pump assembly didnt have the correct spring in it. once that was fixed everything worked as it should. Thank you for all the willingness to help.

[joecar]

Thanks for posting back.

~Moderator~