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Hey guys, i picked up a chipped ze ecu from my budy swapped it for my k8 and for some odd reason the fan doesnt come on with it. It worked fine in his probe . I tried playing around with the throttle position sensor, i heard the fan would come on at a certain point knowing that the car is at idle .( true or false who knows)
Anyway it did not work in my case.
only thing i can think of is a faulty ecu but as i said he said it worked for him. i hope someone has a few suggestoins

well i did do a search on it .
i do have a ze put in with no mods, driving a 92 gs with all the temp sensors installed, with a little mod cause i forgot to swap the necks:(
Why not a regular ecu? i cant get my hands on one and i figured this one would work.
I did read about tps adjustment so i know how to adjust the tps that other adjustment method was thrown at me by a probe guy so i figured i give it a try since we were running out of ideas. i may have worded it wrong before sorry.
the other thing i had the car ideling with the ze ecu and it started to over heat so i swap my old one back and the fan kicked in right if i put the ze back on, it doesnt kick in.
Everything is working fine except the fan isnt coming on with the new ecu. i dont know what to say didnt seem to find any post on this before with this problem. i may be a noob
im pretty sure i picked up a bad ecu , waste of my money:(

OK, great we have a foundation to work from and we can now whittle away at some potential areas.
For the fan to kick on there's a number of different sensors and situations to take place for it to operate correctly. The short-cut method of placing the car diag mode and slightly rotating the throttle cam on the TB to trigger the fan is not a very good method to rely on to do an accurate tps adjust. It's give you a ballpark idea but not one to rely on. And it's just a very quick method to verfify the triggering system for the fan from the tps is working. It by all rights should trigger normally with the ZE ECU like the K8 one does as you said.
I'm not quite sure what is meant by

"all the temp sensors installed, with a little mod cause i forgot to swap the necks"

Does this mean that you drilled and tapped in the correct filler neck spot for the second coolant thermosensor?
It appears from this perspective at this point that there is a possibility that the ECU is defective. If by trying a complete tps with this modded ZE ECU and it still tries to overheat, I'd stear clear of that ecu since you've already confirmed before that the temp triggering system of fan engagement works within specs with the K8 ECU.

There could be a issue with the ecu/harness connectors, like a bent pin or a pulled out wire in the harness.

Thats about all I can think of. Do the ecu reset procedure as well, but I can't really imagine that is the culprit, but it wouldnt hurt.

Also, turning the tps should engage the fan at a certian point, at least it does for me the numerous times I have switched intake manifolds and had to play with it. It also mentions it in my mazda manual.

RizzeRocket wrote:i heard the fan would come on at a certain point knowing that the car is at idle .( true or false who knows)

False. They shouldn't come on until your water temperature gets to about 210 degrees.