Ltk

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

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.

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

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. 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.

Nope, 6 cyl does not work either.

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.

Hey Mike, I contacted Quadzilla Monday and they are sending me out a new PCB board and switch. I will keep you updated on how that turns out. They will send me a wiring harness if that doesn't correct things.

Yes sir I sure will, thanks!

Hate to hear that, Mike! Haven’t been active on these forums in several years just now getting back to driving my 2nd gen. Do you think I’m going to need to buy a new IAT sensor or have my ECM rebuilt?

Yes I purchased the Quadzilla version. Why is it not working? My IAT sensor and ECM should be fine or I'd be throwing a code with the Quadzilla kit uninstalled, right?

So how do I fix this and get my high idle kit to work? Sorry, I’m not following.

What does this mean? Is my IAT sensor bad or is this an ECM problem?

Ahh okay, sorry about that! Took a minute but I figured it out and made it a little easier to see. The pics are as follows: 6 cyl, 3 cyl, MPG, OFF

I am getting the following results for 6 cyl and 3 cyl respectively.

Thanks, I will check that in the morning and report back. I should be able to see that with the OBDlink MX+ (I hope)