2004 Jeep WJ 4.0L JTEC+ Engine & Transmission

[RTXLoki]

Hey everyone I am new to tuning and I am just trying to fix some Fule mapping and maybe change my transmission to get a bit firmer shifts. I have a mostly stock 2004 Jeep Grand Cherokee Laredo 4.0L 2WD and I am just wanting to get better performance. I installed 4 Hole Bosche Injectors that were a little larger than stock and I have no CATS in my exhust system. Where should I start and What should I be looking for. Also If anyone has a stock Tune File for 99-04 WJ with the 4.0L it would be very helpful I saved over mine by accident. I attached a copy of the Tune I have worked on so far for the past few days and I have a feeling many of my values are very wrong. Thank you all for any help!

[greg fricke]

[QUOTE=RTXLoki;777136]Hey everyone I am new to tuning and I am just trying to fix some Fule mapping and maybe change my transmission to get a bit firmer shifts. I have a mostly stock 2004 Jeep Grand Cherokee Laredo 4.0L 2WD and I am just wanting to get better performance. I installed 4 Hole Bosche Injectors that were a little larger than stock and I have no CATS in my exhust system. Where should I start and What should I be looking for. Also If anyone has a stock Tune File for 99-04 WJ with the 4.0L it would be very helpful I saved over mine by accident. I attached a copy of the Tune I have worked on so far for the past few days and I have a feeling many of my values are very wrong. Thank you all for any help![/QUOTE04jeep stockfile.hpt i think i sent ya my 04 jeep rubicon inline 6 stock tune

[greg fricke]

im new here too an im tuning my 04 jeep rubicon . im getting ready to install a turbo an switch to a 5 speed manual

[rfesu]

rtxloki i have done a 4.0 tune or two

there is no injector constant available in hptuners for that ecm, you need to fix your injectors first. so what you want to do is go ahead and do some datalogs for trims. for a starting point what i would do is take LTFT+STFT and kinda get an average of how much trimming is going on and for starters multiply your whole VE table by that. for example if your trims are kinda -10% then take your whole VE table and multiply by .90. then take more logs and fine tune it from there.

this ecm is really primitive and a bit finicky to tune

first thing is i found the stock calibration was like 9 degrees short of timing advance across the board. probably because it has no knock sensor. if you have consistent fuel go ahead and stuff a bunch more timing into it, it'll wake it up a bit.

shift points are definitely where you see the most gains

i have attached a stock HPT file from my 1999 WJ as requested. it is a canadian model single cat. i have also attached a tune with really aggressive shift tables and timing that i use on my WJ off road. i recommend copying the shift tables but nothing from the fuel/timing as your injectors and local fuel quality may differ

the other pain is this thing uses TPS voltage for shifting rather than scaled TPS to a percent so if your TPS is not identical to mine in every way it wont shift right with these tables.

hope this helps