I did the fan mod (ECU grounded to switch) and have noticed something weird: when I turn the switch to 'on' (grounding the wire) the car begins bucking and jerking badly, but only under light load conditions, i.e. if I am on the gas the jerkiness goes away. Same thing now happens (didn't before the mod) with turning the a/c on, so it must be cooling fan related.....anyone else have any similar trouble?

 

if the ecu sees load it raises the idle, and if it sees load and there is'nt any it can get confused

mike

 

The odd thing is, it just started doing it.....I have had the fan mod since last year.......
Just for grins I disconnected the wire to the ECU and have been driving all around, and...everything is working fine, no jerking.....
I wonder what that lower temperature sending unit
(from a Miata) part number is.....I think I would rather have the fans come on at a lower temp, rather than run longer with the car shut off anyway....or else do the OTHER fan mod, where you can simply turn the fans on anytime you want........