Fan "ON" is a "Ground Signal".
0411 four cylinder.jpg
I'm wondering if maybe the '0411 Four Cylinder Coil-On-Plug Ignition System will work without a Cam Position Sensor . . . Post #3 in this tread.
Likely the .bin file will still need Eight Cylinders and a Cylinder Volume equivalent to the Four Cylinder Volume?
dave w
Once I get things straight on this thing I plan to play with it.
I'm looking at it like this.
I have a 2.5L engine, I'm running it on a PCM that thinks it's running a 5.3L engine.
The 2.5L is half of the 5.3L (about). I'm using 1/2 of the injectors and 1/2 the ignition.
Each O2 sensor is getting 2.5L of exhaust (both are in the same pipe could lead to issues ???)
Cylinder volume is the same in both engines (close). It's going to put the same amount of fuel to each cylinder.
The biggest issue I foresee is the MAF will be looking for twice the air flow it's going to get. And I haven't figured out how to delete it yet.
I know it can be done, so I've got to learn how.
Perhaps adjusting the MAF Tables for 2.5 Liter is an option? Possibly "half" the grams per second V8 vs. Four Cylinder?
Perhaps check timing with a timing light that has a "dial indicator" for degrees of advance? The '0411 spark table is Grams Cylinder vs. RPM (MAF vs. RPM)
From EFI Live Tutorial:
Going MAFless
When fitting a 2 or 3-bar MAP sensor you must disable the MAF sensor. It is possible to leave the MAF sensor in place. This will need to be done on the 85mm MAF as the Intake Temp Sensor is located in the MAF housing. Alternatively, you could relocate the IAT using on older style IAT sensor. Even with the MAF still in place, the PCM must be forced to ignore the MAF signal.
To disable the MAF sensor:
Set the Engine Diagnostics->Engine Diagnostics->MAF->Parameters:
{C2901} MAF High Frequency Fail 1: 1Hz
{C2902} MAF High Frequency Fail 2: 1Hz If calibration {C2902} is not available in the operating system that you are using, then ignore this step.
{C2903} MAF High Frequency Fail Limit: 1
{C2907} MAF Test Min Engine Speed: 300 RPM
{C2908} MAF Test Min Run Time: 0.1 seconds
Set the Engine Diagnostics->Engine DTC processing Enablers:
P0101 ‘C’ Non Emissions
P0102 ‘C’ Non Emissions
P0103 ‘C’ Non Emissions
Set the Engine Diagnostics->Engine DTC MIL Enablers:
P0101 ‘No MIL’
P0102 ‘No MIL’
P0103 ‘No MIL’
When going MAFless and/or boosted on vehicles with Electronic Throttle Control, you will most likely need to increase {C6101} ETC Predicted Airflow, by significant amounts to stop the PCM going into reduced power mode.
Set the Transmission Diagnostics->Transmission DTC Fault Max Pressure Enablers
P0101 ‘No’
P0102 ‘No’
P0103 ‘No’
Set the Transmission Diagnostics->Transmission Failsafe Enablers:
Set all airflow related enablers to ‘No’ to prevent the transmission from going into failsafe mode due to the MAF being disabled.
I given up on using the Jeep throttle body. I just can't get the IAC to work with the GM computer.
The lowest I can get it to idle is @1100 and it's always changing 100 -200 RPM.
I made an adaptor for the throttle body I have from a 2004 4.3L V6 and it works good so far.
It's idling at 650 -700 RPM just like it should be. I'll be installing my wide band and gauge tomorrow so I can start tuning it.
I've turned the MAF off for the moment. I've never done that before and just wanted to see how much it affects it.
After putting the GM throttle body on this engine and how it responded, I think I need to get another one for my 4.0L in my truck, that I'm running on a P59.
When I put the 7749 into my Toyota I grafted on the IAC adapter plate from a 4.0 TB. I ended up switching out the Jeep IAC for a GM IAC. You've already made your adapter but if you'd like I will see if I can find the number of the IAC I used.I given up on using the Jeep throttle body. I just can't get the IAC to work with the GM computer.
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