Help with Quadzilla 3 cylinder/6 cylinder box

[Ltk]

On 1/8/2025 at 5:45 PM, Mopar1973Man said:

Keep me posted please... 

Received the PCB board and new rotator switch. Installed it, still acts the same. When truck is running and I switch from off to 3 cyl I got a big idle surge and then nothing. Any thoughts?

Quadzilla has mailed me out a new harness so I'm still waiting for that right now.

[Royal Squire]

@LtkDoes the 6 cyl high idle work?

[Mopar1973Man]

12 hours ago, Royal Squire said:

@LtkDoes the 6 cyl high idle work?

Good question.

[Ltk]

49 minutes ago, Mopar1973Man said:

Good question.

 

13 hours ago, Royal Squire said:

@LtkDoes the 6 cyl high idle work?

Nope, 6 cyl does not work either. 

[Mopar1973Man]

Go back and check. 

 

6 cyl should show 26°F IAT and 123°F ECT

3 cyl should show 13°F IAT and normal coolant display.

 

Operation 

 

Turn switch to setting you wish. Start the engine. Then after high idle starts in 2 to 3 minutes you may turn it off again and high idle will continue till 170°F. 

 

NOTE: To slow of switch change could trigger only 3 cyl mode. If so turn the engine off and wait 10 seconds and restart to clear the previous 3 cylinder mode.

[Ltk]

17 minutes ago, Mopar1973Man said:

Go back and check. 

 

6 cyl should show 26°F IAT and 123°F ECT

3 cyl should show 13°F IAT and normal coolant display.

 

Operation 

 

Turn switch to setting you wish. Start the engine. Then after high idle starts in 2 to 3 minutes you may turn it off again and high idle will continue till 170°F. 

 

NOTE: To slow of switch change could trigger only 3 cyl mode. If so turn the engine off and wait 10 seconds and restart to clear the previous 3 cylinder mode.

 

Followed the exact startup procedure you described with the new PCB board Quadzilla sent me. Here’s the results after 5 minutes of idling; 6 cyl mode engaged on the switch, still at idle RPM. 

 

 

24 minutes ago, Mopar1973Man said:

Go back and check. 

 

6 cyl should show 26°F IAT and 123°F ECT

3 cyl should show 13°F IAT and normal coolant display.

 

Operation 

 

Turn switch to setting you wish. Start the engine. Then after high idle starts in 2 to 3 minutes you may turn it off again and high idle will continue till 170°F. 

 

NOTE: To slow of switch change could trigger only 3 cyl mode. If so turn the engine off and wait 10 seconds and restart to clear the previous 3 cylinder mode.

Here’s the exact same procedure that I described above , except 3 cylinder mode instead of 6 cylinder. 5 minutes of waiting after restart with 3 cyl enabled before start. No idle change, here’s the IAT and ECT temperatures. 

[Mopar1973Man]

Still something wrong. Wrong values for 3 cyl and 6 cyl is half right with 123°F coolant.

 

@Quadzilla Power

 

Edited January 19 by Mopar1973Man

[Ltk]

33 minutes ago, Mopar1973Man said:

Still something wrong. Wrong values for 3 cyl and 6 cyl is half right with 123°F coolant.

 

@Quadzilla Power

 

Is it possible that my IAT sensor is bad? Zero codes on the truck with the Quadzilla harness unhooked though. 

[Mopar1973Man]

No. Because in fooler mode the resistance is fixed to a particular value its like you have internal resistance differences or there is a malfunction some how.

• OFF - All normal values of IAT and ECT sensors. No fooling done.
• MPG - IAT sensor is disconnected and forced a value of 143℉.
• 6 CYL - IAT sensor is disconnected and forced a value of 26℉ and the ECT sensor is disconnected and forced a value 123℉
• 3 CYL - IAT sensor is disconnected and forced a value of 13℉.

If these values cannot be obtained then high idle system will not work properly. The key notes the IAT is the trigger to start the high idle and the ECT can prolong the high idle only if the mode holds it below shut off. Hence why the 6 CYL can be used for jump starting because the coolant never reaches the cutoff point.

 

If you wish, give me a call at (208) 315-1470 - 9am to 5pm MST. I'll go over all this in greater detail.

Edited January 22 by Mopar1973Man

[Ltk]

On 1/22/2025 at 2:07 PM, Mopar1973Man said:

No. Because in fooler mode the resistance is fixed to a particular value its like you have internal resistance differences or there is a malfunction some how.

• OFF - All normal values of IAT and ECT sensors. No fooling done.
• MPG - IAT sensor is disconnected and forced a value of 143℉.
• 6 CYL - IAT sensor is disconnected and forced a value of 26℉ and the ECT sensor is disconnected and forced a value 123℉
• 3 CYL - IAT sensor is disconnected and forced a value of 13℉.

If these values cannot be obtained then high idle system will not work properly. The key notes the IAT is the trigger to start the high idle and the ECT can prolong the high idle only if the mode holds it below shut off. Hence why the 6 CYL can be used for jump starting because the coolant never reaches the cutoff point.

 

If you wish, give me a call at (208) 315-1470 - 9am to 5pm MST. I'll go over all this in greater detail.

 

We were right, the harness itself was wired incorrectly. IAT and ECT plugs reversed. New harness arrived and problem solved! 3 and 6 both work with correct values displayed. 

[Mopar1973Man]

Right on. I thought it was weird. 

[Ltk]

2 hours ago, Mopar1973Man said:

Right on. I thought it was weird. 

Yes sir it was driving me crazy as well, thanks for the phone calls and your help! 

[Mopar1973Man]

Not a problem and your welcome always here to support the Cummins family.