I wired up my high idle fooler according to moparman's diagram. With the IAT harness hooked back onto the sensor and just the coolant temp fooler on, the engine will still hit the 3 cylinder mode and the temp outside is around 34 degrees F. If I understand the system right this shouldn't be happening at temps this warm. Can somebody give me some ideas?

From what I can tell from his writeup, with the IAT fooler off (so it uses actual intake temperature) and the ECT fooler on (being FOOLED it tells the computer it is 123F). So if the computer sees 123F coolant temp yet probably 50F intake temp when running.. Yeah I am not sure. As far as I know, it has to be below 10F or just very cold to get the 3cyl to turn on. I assume you did all 3 switches? The 3cyl IAT fooler, the high idle IAT fooler and te ECT fooler? Are you sure you are hitting the right switch? Let me study his writeup some more.So the ECT fooler tells the engine it is only 123F, which meets one condition for the high idle since it shuts off at 170F, but if the IAT fooler is off, then it sees that 34F+ so I don't think it should turn the high idle on, and especially not the 3 cyl thing. If you have a scan gauge it might help you out. See if it shows the coolant temp being 123F or see what it shows the IAT temp as being. I think you might be hitting the wrong switch.I wonder if the computer senses that the coolant is a constant 123F and says the hell with it and kicks on the 3cyl to try and get that temp gauge to move.. If it takes a couple minutes for it to kick all that stuff on normally I am beginning to think it is time based. :confused:Why are you turning just the ECT fooler on anyways? It's not one of the scenarios he has specified so I don't know what you are trying to do.

Edited January 16, 201015 yr by ISX

I was turning just the ect fooler on to trigger the 6 cyl idle. I disconnected my IAT fooler and put the factory connector back on the sensor to bypass my wiring in case I had done something wrong. If I understand right fooling just the ect should trigger the 6 cyl high idle because the computer will know that the air temp is above its 3 cylinder parameter.

From what I can tell, you need to turn it and the high idle IAT fooler on. I think all the ECT sensor does is tells the 3cyl and high idle when they need to shut off (170F) but doesn't necessarily tell it to high idle, I think the IAT sensor is what tells it to high idle. When the engine is below 140F, then you don't mess with the ECT at all since it will basically be fooling it for no reason (since it fools it to 123F and the engine will be around or less than that temperature anyways). I believe the ECT fooler is only needed when you want to high idle and the engine is above 140F. If it is above that temperature, the high idle has no reason to kick on, regardless of IAT. So to get high idle on a warm engine (140F or above) you turn the ECT fooler on and hit the high idle fooler and then once it is turned on, you can shut both of those off and it will stay high idling until 170F. The engine wants to be at 170F+ but if you start it and its over 140F it knows it thinks it is a waste to high idle so it doesn't. You have to use both foolers so that it thinks it is starting from a cold engine and when you turn the foolers off, it is still on the cold engine cycle, which ends at 170F..

Not bad ISX you got that right on the money... setting high idle from cold you only need the IAt fooler... After the high idle starts then flip it off... Now if going for high idle on a warm engine you must use the ECT fooler too to trigger it... But remember the high idle setting you use will remain till the engine is shut off... So if you set 3 cyl high on a cod morning and head to town and try setting 6 cyl high idle it will fall back to the 3cyl because it was last set mode. The way to reset this is to turn the engine off for a extend period of time (15 Mintues or so)

Thanks guys, that was good info

Well today I had time again to work on my high idle fooler and there still seems to be some sort of issue. It will always go to 3 cyl mode even when I have it selected to 6 cyl. I don't have a scangauge to check what temp i'm sending to the ecm but I used an ohm meter to check the resistance and it is at 38.6K for the 6 cyl mode and 55.8 for the 3 cyl mode. Can somebody help me? Well I think I just answered my own question so don't worry about this unless I post again:rolleyes2:

Edited January 21, 201015 yr by volkswagon

So it all works now?

It sure does:hyper:

Ok... so what was the problem??? I'd love to hear it?

The problem was that I had forgotten that part that you wrote about how the ecm remembers which idle mode it was last on and that it goes back to that until the engine is shut off for a while.

Ahhh... Yeah that does hang few people including myself... (D'Oh!)