Lady Redhawk

iTrader: (6)

If there is no answer to this: https://ls1tech.com/forums/pcm-diagnostics-tuning/426348-full-line-pressure-a4-sd-tune.html and line pressure is being effect uncontrollabley, we need to rethink SD tune in A4!

Brains

iTrader: (7)

Its more a problem with the 98's I believe. I haven't had this issue with the 99+ cars at all.

Lady Redhawk

iTrader: (6)

I've had this problem in my 2001 F-body A4 and in a 01 C5.

jmm98LS1

iTrader: (28)

If you're using HPTuners, email them your .bin file and they will fix it. I just did it yesterday and the problem is fixed. Don't know what they do, but it works. If you're using something other than HPT, dunno what the answer is.

foff667

iTrader: (2)

hmmm i was told this is only in 98-00 code...wonder why this happend to those cars :shrug:

Lady Redhawk

iTrader: (6)

The Vettes are really a different issue than the f-bodies. They go into a reduced power mode that would also lock them into 3rd gear, but that can be tuned out. It's the line pressure issue that is disturbing. Among other perimeters and calculations the pcm uses to determined line pressure at any given area, it also uses torque and load calculations that comes partly from the MAF.

If the line pressure has already been turned up mechanically (turned screw 1/4 turn or so...) and/or tuning, Need to keep close watch on the line pressure in SD mode.

chrisj6

I havent had any issues with this in my 99 truck, although I have an 01 pcm and OS.

Chris

ToplessTexan

A setup warranting SD might well also benefit from conversion to a vaccuum modulator. Just a thought...

Runn

I have this problem on my car and now i have tuned in my VE is there any way to calibrate the MAF after the new VE... But will the new MAF values change the PCM load calculations?