4l60e

[lbheart]

Hi folks,

I'm from in australia and i have an australian ss commodore. its our version of chevy
it has the ls1 ..... 5.7 litre ..... 350 chev and the 4l60e tansmission.

now third and fourth gear where slipping so i dropped the gearbox and took it in for reconditioning and i was told that it is a common problem and after reconditioning the gearbox i would need to have the computer reprogrammed to increase the line pressure because what supposedly happens is when on the highway if the MAF sensor is not at optimal working condition it can give poor reading and this causes the computer to drop the line pressures down and buggers the clutches.

I have efi live from when i did a custom install of a ls2, 6.2 litre chevy into my nissan patrol.

can anyone tell me how using efi live ( i think i have the first version) i can increase this line pressure???

thanks alot in advance/

[joecar]

Do you have any logs showing the pid TFMPRS...?

Post your tune file.

How many miles on the transmission before it failed...?

If MAF and VE are not correct then PCM can calculate low line pressure, it has to be monitored to see if it is correct.

[lbheart]

Hi mate
Thanks for replying

To be honest im not that fkuent with efi live.
I used it once to remove VATS in order to get a conversion up and running and take it down
Fir a dyno tune

I just wanna icrease it anyway to be sure.

Im replacing the MAF with a brand new one with tge new gearbox.
What does VE stand for?

Sorry about spelling using my phone

Ill plug it in tonight and see if I can save tune

[lbheart]

my tune is attached mate

i assume i just adjust the base pressure 3>4 and 2>3????


where do i find this pod business??

[joecar]

VE = Volumetric Efficiency table... which is in this case is actually cylinder airmass table (normalized for temperature and pressure).

PCM switches between VE and MAF tables depending on operating conditions.


PCM calculates base line pressure from engine torque which it calculates from cylinder airmass which it derives from VE and MAF tables.

If either VE or MAF tables are not correct, the commanded line pressure may be low (allows clutch/band slipping).

[joecar]

In the tables (reverse engineered) there are no base pressure tables... there are only shift pressure tables and adaptive pressure modification tables (defining how far PCM modifies/adapts a shift).

[joecar]

In scantool, goto PIDs tab, you will see a bunch of pids that you can log...

you want: VSS, RPM, MAF, MAP, DYNAIR, DYNCYLAIR, ECT, IAT, TFT, SPARKADV, GEAR, TCCMODE, ENGTRQ, TFMPRS and a few others... try VETABLE_DMA (your OS might not support it).

[lbheart]

mate I just wanna know how to increase the line pressures and maybe turn off torque converter lockup in third. like fucking short answer ya know?

I cant log all that until I have the new box in and all up and running and as I said earlier I don't wanna do that until I increase line pressure.

while I genuinely appreciate your help mate I don't need all the technical mumbo jumbo bullshit i'm just chasing the short answer.

cheers.

[joecar]

Line pressure can't be upped easily like that without messing with the VE and MAF tables

(there are no tables for base line pressure; there are tables for line pressure during a shift, you can try increasing these, but these only have effect during a shift... so your base line pressure will still be low).


Preventing TCC lockup in 3rd gear: set the apply curve to max value.


In truth there is no short answer because of interaction among the tables, I don't know what your tables contain.

To be able to talk about the concepts and tables we need some "mumbo-jumbo" terms... (just bump up the table for the "thingy" doesn't cut it)

[IJ.]

Would Force Motor do what he's after Joe?