Chrysler/Jeep 4.0L Tuning Thread

[The_Magic_SpoolBus]

Hello everyone, I am hoping that by starting this thread I might inspire you, or others to embark on the journey of figuring out the beloved 4.0L engine with me. The past 6 years I?ve spend a massive amount of my time and money on everything from XJs, ZJs, WJs and even a few TJs, all of them having the bulletproof 4.0L engine.

The 4.0L is a well built and naturally balanced engine, that doesn?t exactly make higher horsepower and torque numbers. I recently over the last 3 years was working on a home brew turbo setup on a 4.0 and stumbled upon HPTuners. I bought my dongle and got to work. I?ve started getting fairly knowledgeable with making changes but I am still very far behind. I was hoping that I could find some people that may have a little more documentation than I have already sourced up.

So far I?ve managed to find the ECU operating strategy and what sort of factors are actually in play with these computers, and with that I would like if someone would be willing to work with me and help me develop a full blown guide and explanation sheet for those that may come after us. Someone has to do the legwork for this all to be easily accessible for everyone. I?m willing to start that process.

I have tons of tune files and documents from Mopar that I?d be willing to share with anyone who may want to help, just shoot me a DM, or post here. I?ll add all my tune files and documentation below as well.

[jfabrication]

I sent you a DM

[Geeknahalf]

Hi folks, any update?

I have invested heavily into many go fast goodies for my TJ, and would LOVE to get involved in this as well. I have it tuned, however, the tuner locked the tune to protect his intellectual property that I paid for. So, I am basically hostage to him if i make any changes and at ~$500 or more a pop, it adds to my build price exponentially anytime a make a moderate change. I plan to make many, many changes; this is a never ending project.

Please let me know!

[Geeknahalf]

Have any tuning walk thrus for 2004 Jeep TJ 4.0 w auto trans?

[hyperbolecubed]

Have any tuning walk thrus for 2004 Jeep TJ 4.0 w auto trans?

Whats your build? You generally want a wideband to dial in your fuel map and a knock sensor to dial in timing.

[Geeknahalf]

Hey Hyperbolecubed,

Any recommendations on a knock sensor?

Here's my build sheet:

Engine/Trans:
Clegg Engs. stage 2 4.6 stroker kit w/ chromoly rings, forged rod n pistons, ARP rod bolts
Eddy head, stock valve size
Compression about 10.1
Banks header
New Hi Flow exhaust w flowmaster d40 muffler
Harland Sharp roller rocker 1.75
HiFlow water pump
Comp Cams 163-301-5
ATI Harmonic Balancer
Arp Head Bolts
Hi Flow oil pump
BBK 62mm TB
ATS 900RPM Stall Torque Converter
ATS Valve body w/shift kit
4 core alum radiator
AEM 10-0334 Wideband O2
Trans temp gauge
Mech Oil press gauge
viper coil upgrade
265LPH Fuel Pump
19 row stacked plate trans cooler
6AN Black Flexible PTFE Transmission Cooler Hose Lines & Fitting


Suspension:
Zone 3.75" Lift Kit
Dana HP 30 Front
Dana 35 Limited Slip (Factory but worth mentioning)
SYE Kit JB (Conversions)
B&M TC Cable Conversion Kit
Tom Woods Rear Driveshaft
33x10.5R15 tires

I've got the MPVI 3, but no idea how to tune. Right now it has 85 octane tune that's locked so tuner can protect his intellectual property. It runs great but not taking advantage of the go-fast goodies I have. I plan on making many more mods, and don't want to shell out $500 min each time for tune.

[hyperbolecubed]

Hey Hyperbolecubed,

Any recommendations on a knock sensor?

Here's my build sheet:

Engine/Trans:
Clegg Engs. stage 2 4.6 stroker kit w/ chromoly rings, forged rod n pistons, ARP rod bolts
Eddy head, stock valve size
Compression about 10.1
Banks header
New Hi Flow exhaust w flowmaster d40 muffler
Harland Sharp roller rocker 1.75
HiFlow water pump
Comp Cams 163-301-5
ATI Harmonic Balancer
Arp Head Bolts
Hi Flow oil pump
BBK 62mm TB
ATS 900RPM Stall Torque Converter
ATS Valve body w/shift kit
4 core alum radiator
AEM 10-0334 Wideband O2
Trans temp gauge
Mech Oil press gauge
viper coil upgrade
265LPH Fuel Pump
19 row stacked plate trans cooler
6AN Black Flexible PTFE Transmission Cooler Hose Lines & Fitting


Suspension:
Zone 3.75" Lift Kit
Dana HP 30 Front
Dana 35 Limited Slip (Factory but worth mentioning)
SYE Kit JB (Conversions)
B&M TC Cable Conversion Kit
Tom Woods Rear Driveshaft
33x10.5R15 tires

I've got the MPVI 3, but no idea how to tune. Right now it has 85 octane tune that's locked so tuner can protect his intellectual property. It runs great but not taking advantage of the go-fast goodies I have. I plan on making many more mods, and don't want to shell out $500 min each time for tune.

https://viatrack.ca/ thats what i use. On rockauto you can buy a knock sensor mount for your jeep that fits a threaded hole in the block already. I have the prolink + and have the knock sensor connected to that. when it detects knock the readings dip down below 1 volt and goes back up to around 4.5 volts when there's no knock. You'll want to tune AFR first in open loop from what I've gathered. once that's done turn on closed loop and adjust timing in 2 degree increments and watch for knock and back off 2 degrees once knock is reached. I added a supercharger to my jeep 4.0 and now getting bigger injectors suggested by my tuner.

[Geeknahalf]

I was looking at that earlier this week. You connected to prolink + and configured in scanner as analog 2? Do you have schematics of how you connected everything you can send my way?
Thx!