Turbo 4 Liter

[Jezza]

I thought I would do a series of posts regarding the AEM Infinity install. I guess we can call this "Infinity Part 1".

As a bit of an overview the Infinity is used as a stand alone, but the factory PCM is kept to drive the gauges as well as the alternator, A/C and cruise control. The Infinity is used to control fuel injectors, coils, idle stepper and a few other things. The PCM is still in its original mounting position, and is connected to the Infinity by a jumper harness that separates the PCM items from the Infinity items and the shared items. The Infinity is mounted under the dash on the driver's side to the bottom of the steering column.

I'm going to start off with what I consider probably the most important aspect of stand alone computer integration, QR 0 the cam sensor, crank sensor and firing order. Without all of those items working properly together it will never start and run correctly. The AEM Infinity has an entire library of compatible cam and crank patterns. Unfortunately the Jeep 4.0 engine is not a supposed engine meaning there is no option to use the factory generated patterns. The Infinity does however have the ability to accept generic patterns. There are several options available for patterns, but I chose the 6 tooth hall effect sensor crank pattern with the 1 tooth hall effect sensor cam sensor. The cam sensor was easy for me as the 2002 has the pre-opda hall effect cam sensor. It uses a single tooth wheel and generates a single tooth pulse for every 720 degrees of crankshaft rotation. I know that the later opda units have several teeth on the cam sensor pickup wheel. Those would not work with the Infinity cam pickup without modifications. I simply tee'd into the cam sensor output and wired that to the Infinity.
For the crank sensor things are a bit more complicated. The 2002 uses a flywheel based crank pattern. The pattern is 3 sets of 4 teeth. I could have made some filler blocks to weld in and make the pattern 6 even spaced teeth, however I wanted to retain the factory crank pattern to drive the tachometer through the factory PCM. What I ended up doing was modifying the front crank pulley by cutting 6 even spaced teeth in the shell. I then added a sensor and bracket to the front of the engine that picks up the crankshaft position and sends the signal to the Infinity. Once that was done I could program the Infinity to use the 6 tooth crank and 1 tooth cam pattern. I then set the firing order to the factory Jeep 4.0 pattern. Next I set the option for wasted spark and assigned the coils. At this point I could crank the engine and check the timing. The Infinity has a setting for trigger offset. This setting allows you to set the degrees of separation between the cam and crank pattern theoretical TDC and actual mechanical cylinder #1 TDC. This is achieved by use of a wizard tool. Once setup correctly the timing displayed in the Infinity is equal to the actual timing advance at the engine. At that point cranking the engine results in the Infinity displaying RPM and sync status.

Images
1. Modified crank damper
2. Crank sensor mount
3. Factory PCM with jumper harness
4. Modified damper with sensor and bracket
5. Infinity mount under dash

 

[hosejockey69]

Now there's something you don't see every day!

 

[SkylinesSuck]

So you have a dizzy and not an OPDA thingy, right? And I'm assuming you fabbed the bracket for the hall sensor yourself?

 

[Jezza]

So you have a dizzy and not an OPDA thingy, right? And I'm assuming you fabbed the bracket for the hall sensor yourself?

I have a non-opda non-distributer model, used from 2000-2004 like this one.
The crank sensor bracket I fabbed myself.

 

[SkylinesSuck]

Oh, weird. Didn't know there was anything in-between. Roger.

 

[Brianj5600]

@Jezza Thank you for taking the time to document this.

 

[Jezza]

"Infinity Part 2"

I figured for the second part I would briefly discuss the inputs and sensors I am using. The Infinity uses several of the same sensors as the factory PCM. They can be configured in the software to report the proper values and these values are used by the internal firmware to calculate fuel and spark. I am just going to list the sensors I am using, however the Infinity can be configured to use other types of sensors as well.

Map sensor: I am using the GM 2 BAR sensor P/N 12615136 this sensor reports only to the Infinity and the factory PCM is blind to manifold pressure and throws the predictable codes for no sensor being connected.

Throttle position: I am using the stock TPS and the sensor output is shared between the Infinity and PCM.

Intake air temp: I am using the AEM 30-2010 sensor for the Infinity only. My AEM sensor is installed in the pipe post intercooler and pre-throttle body. The factory IAT is still in the intake manifold and still connected to the PCM.

Coolant temp sensor: I am using the factory coolant temp sensor in the factory location. The sensor output is shared between the Infinity and the PCM. This is a bit tricky because of the pull-up voltage on temp channels in both units, so voltage must be used in the Infinity. I had to set up a custom lookup table for the coolant sensor to report correctly.

Fuel pressure sensor: For fuel pressure I am using the AEM 30-2130-100 pressure sensor. It is plumbed to the schrader valve on the fuel rail. The fuel pressure is used by the Infinity only.

Wideband air/fuel sensor: I am using the AEM 30-4900 failsafe gauge. This has a Bosch LSU 4.2 wideband sensor. It outputs a 0-5v signal that I have input into the Infinity where the voltage is converted into actual air/fuel ratio. The wideband is for the Infinity only, however the factory O2 sensors are still installed and connected to the PCM.

Knock sensor: I am using a factory Mopar 05033316AB sensor from a Ram 1500 V8. This signal is used by the Infinity only.

Vehicle speed sensor: I am still using the factory sensor in the transfer case output. The signal is sent directly to the Infinity and processed through the software where it is changed to match the tire size. The software has the ability to modify the signal properly for any tire size that will fit a Jeep. The modified signal is then output to the PCM where it sends data to the dash cluster.

Barometric pressure: I am using the factory Jeep 4.0 MAP sensor to read barometric pressure. I was able to find the calibration data for the factory sensor and use it to report baro data. This data is only used by the Infinity and is surprisingly accurate. I have an altitude channel in the software that reports within a few hundred feet on a day with no weather going on.

Oil pressure: I am using the factory oil pressure sensor to input data to the Infinity as well as the PCM. The Infinity has a calibration for the HEMI engines that is spot on for the Jeep sensor. The factory oil pressure sensor is surprisingly accurate and is quite responsive.

Driver switch: I have a 4 position switch I have going to the Infinity. I use this switch for boost control as well as rev limit control. Infinity input only.

Extended idle switch: I have a simple on-off switch to enable the high idle in the Infinity. Infinity input only.

Intercooler water temp: I am using the GM 12146312 sensor to report the intercooler water temp to the Infinity.

I think that pretty much covers the input sensors I am using. I tried to use as many of the factory sensor as I could to reduce cost. This caused me a bit of extra work, but I feel like it makes for a cleaner install that is more easily reversed. It also saves on running extra wires and connectors.

 

[SkylinesSuck]

This info is gold. I am a bit curious how well the knock sensor works i.e. how specifically it's calibrated to a ram v8 vs the noises the I6 puts out. Where did you mount it?

 

[Jezza]

This info is gold. I am a bit curious how well the knock sensor works i.e. how specifically it's calibrated to a ram v8 vs the noises the I6 puts out. Where did you mount it?

The sensor is pretty universal. That part number is used on several other Dodge platforms including the Viper V10 and the minivan V6. It has a frequency around 9KHz. Then the AEM has a built in amplifier to gain the signal enough to log. Once I had it set up I forced knocked the engine to test the setup. It is quite obvious when knock is present. I have it mounted high on the block toward the back.

 

[Jezza]

I thought I would finish up the AEM posts by discussing some of the options and features that I have found useful in the AEM vs HP Tuners. The first and probably biggest advantage of a stand alone to a flash software is the ability to have full control. Software like HP Tuners gives you access to the tables and information that they have been able to crack and reverse engineer. The problem is many times there are tables in the background that have not been unlocked and affect the tune usually in adverse and unpredictable ways. With full stand alone units like the AEM you have access to most if not all of the tables that drive the tune. The other big advantage is being able to set up the software to suit your application. Options are available to run different fuel and spark models like 1, 2 or more BAR MAP sensors and scale the maps to match the sensor being used, or use a TPS based model that does not use a MAP sensor. Then there is the engine protection tables. Settings are available to set limits and actions when certain undesired engine conditions occur. Right now I am using the oil pressure, coolant temp, boost maximum and the lambda protection tables. They allow the user to set high and low limits for different conditions and can display an alarm or turn on a RPM limit if values deviate from the desired range. Another feature is the ability to have user based outputs. The only ones I am currently using is the boost solenoid, speedometer and a engine warning light. Other useful outputs might be a cooling fan, AC, fuel pump etc. So far everything is working very well. The idle stepper motor has taken a bit of tuning to get working correctly but seems to be working well now. The driveablity is much better than Hp ever was.

 

[Irun]

This is impressive work!

 

[Jezza]

Getting a little bit of work done here and there between working every day for the last month. Rear end is still at powder coat, but should be done any day. I have an ARB air locker for the rear along with chromoly shafts and a new 4.56 gear set. In the process of putting in the tummy tuck and raising the engine up more I found my exhaust doesn't fit anymore. I realized that before I refit the exhaust I should probably install the Genright inner fenders in the case that the turbo or piping doesn't fit with the new inners. After test fitting the fenders and inners everything fits fine. I will have to remake my intercooler water tank and either make or relocate the washer fluid tank. They don't fit at all with the inners.

 

[NashvilleTJ]

Nice work.

 

[SurfinLife]

I am having a new issue now though.. and after intense diagnostics, It's looking to be a crankcase pressure issue. Since this Jeep doesn't use a PVC system, did you install one? Part number?
I left my valve cover open to atmosphere, vs back into the manifold..... this needs to change because I am setup for more boost....was using only 4-5psi, and now I'm up to 7-8psi and anytime I come to a stop after wot and boost, I have a hard time idling... found out the engine will run lean. If I turn off the engine and wait 5 seconds before restarting, all is back to normal until I boost again....
Are you able to log your map sensor? Meaning, with HPTUNERS I setup a PID to record the barometric pressure side of the 2bar map, and I've never logged this before my issue so I have no reference....but I notice that the baro at start will be 102.3kpa as long as I start away from boost, throughout my drive. When I hit wot/boost, the baro will rise with the boost pressure and remain high, even after I return to idle. Is this normal? Just trying to see if that is throwing off my fuel map and making it lean, or if it's a side observation that's not related. I've replaced the map with a new one, same thing happens.

So, do you mind sharing your method of managing crankcase pressure? I see the valve cover air inlet to the intake pre turbo, but what about to the manifold?

Thanks.

Solved!
Fixed the crankcase pressure issue, and my idle after boost issue.

I'll be opening a HPT trouble ticket.

Looks like HPT did a firmware/software update. This would be fine if I was finished tuning the PCM, but I am not. So what I found out is the newest update REMOVED parameter option... in do so I lost menu options that I was using to tune and this corrupted my PCM.

The fix. Reinstalled the factory tune (full write), followed by retuning the factory file by manually entering data in the tables. Do not use the file comparison option to transfer data....this created other problems.

 

[Jezza]

Solved!
Fixed the crankcase pressure issue, and my idle after boost issue.

I'll be opening a HPT trouble ticket.

Looks like HPT did a firmware/software update. This would be fine if I was finished tuning the PCM, but I am not. So what I found out is the newest update REMOVED parameter option... in do so I lost menu options that I was using to tune and this corrupted my PCM.

The fix. Reinstalled the factory tune (full write), followed by retuning the factory file by manually entering data in the tables. Do not use the file comparison option to transfer data....this created other problems.

What was the crankcase pressure issue? Sorry to hear about the issues with HP. I am very hesitant to ever run updates on tuning software. I have been in some real nightmare situations in the past with dead customer cars because the software updated and bricked the PCM. SCT used to be the worst. It seemed that every time I went to use it the software would need an update. I actually need to look at my HP file again and do a bit of tweaking. It's that time of year again when the heep needs its annual emission inspection. I have to put it back on HP and drive cycle it to clear all the monitors.

 

[Jezza]

It's coming together slowly. I have almost finished the fender install. I was surprised at how much stuff mounts to the inner fenders. There's all kinds of garbage hanging on those wheel arches. I have a small list of items that need to be done before it's ready for the road. I went to put the rear end together yesterday and found out that I have the wrong ARB locker. I got a 117 instead of a 116. The 117 is for 3.73 and down ratios. The pinion and ring gear don't even touch when installed. New 116 is on the way, but in the meantime I'm going to run the old 3.73s for a bit. The housing was full of sand after powder coat. I blasted it out several times with a hot power washer and Purple Power. Then I scrubbed it with a wire brush and brake cleaner, but I wouldn't be surprised if there is still a little bit of sand in there. So I'm going to run it for a bit with the old gears to get all the sand out. Besides that all that is left is to do an alignment and fix up the rear section of the exhaust.

 

[Jezza]

Been driving it the last few days and all seems to be working well. Now I'm turning my attention to some of the little details. One of the things I would like to do is replace the GenRight fender vent panels with some custom cut panels. I have some carbon fiber plate that I want to machine the panels out of I just need to settle on a design. These are the top choices I came up with. Thoughts?

 

[cjindna]

Been driving it the last few days and all seems to be working well. Now I'm turning my attention to some of the little details. One of the things I would like to do is replace the GenRight fender vent panels with some custom cut panels. I have some carbon fiber plate that I want to machine the panels out of I just need to settle on a design. These are the top choices I came up with. Thoughts?

View attachment 271064

The slotted version would make for a nice continuation of both the grill and cowl.

 

[SkylinesSuck]

I'm drawn to bottom right for some reason.

 

[srimes]

Been driving it the last few days and all seems to be working well. Now I'm turning my attention to some of the little details. One of the things I would like to do is replace the GenRight fender vent panels with some custom cut panels. I have some carbon fiber plate that I want to machine the panels out of I just need to settle on a design. These are the top choices I came up with. Thoughts?

View attachment 271064

Could you do a diamond plate pattern to match the rocker guards?