View Full Version : Need some help tuning

September 23rd, 2019, 05:31 PM
Long time reader first post. I have a 2005 Isuzu ascender that i just bought for $300 that needed coils (was running on 3 cylinders) i have got them replaced and would like to play with tuning, and help would be appreciated, i am thinking i need to do the following but i am not sure where to start:

Torque Management
Transmission line pressure
Transmission Shift Points
DFCO (not sure where to start with this or why it helps get better milage)
Want to bump the timing (but would like to use the 85 octane we have here in utah)
Smooth Out Spark Tables (I read this helps alot)
Anything else I am missing
Looking for max power but would like to get the best mileage I can.

I Work For Diesel Company and have played with Cummins Tuning but woudl like to get this nailed down.

Here is My 2005 Isuzu Ascender 4.2L 4x4 7seater stock file

September 25th, 2019, 06:29 AM
Hey Lonnon, just replied to your email as well.

Transmission and shift pressures are fairly subjective and you'll want to play around with them a bit. The I6 has lots of TM that can be removed, I've had good luck running minimal/none as the 60E can handle the ~275hp/tq.

Timing- expect to pull a bunch out of all tables, with the 87 we have now vs when these trucks were built, they knock. Using 85 will make it even more knock-prone, so best results are going to be by pulling timing out so the PCM doesnt try to increase timing, knock, and pull timing. Smoothing them out a bit helps too.

Max power will come with 91+ octane simply because it won't burn as quickly like 85/87, if you want to only run 85 then you won't be able to make maximum power.

September 25th, 2019, 04:51 PM

Thanks for the reply i have started playing with my tune, and have been looking at some of the other tunes in the forum and comparing to what i have changed i will keep you and others updated on my progress even though this LL* forum seems to be dead i think i am the first one to post in months.