| The 'Initial' 90-91-92 ( with IAV's ) Idle Circuit was an 'Open Loop Mixture' that forced the Idle Mixture richer than necessary, and forced to IAV to pump air down the secondary piped lines to the Cat Converters to 'Fix' the mixture enough to keep the cats lit off. The Idea is left over from late 80's Cars. Only during Idle. The 93 and later 'Idle Circuit' is a Limited version of 'Closed Loop', as the Ignition Timing is fixed at 15 Deg, the O2 Feedback is now Slower to adjust, and the 'Mixture Range' is also limited.. But the IAV's are gone, and the O2 Sensor feedback is necessary to keep the Cats lit off.. GENERALLY ALL aftermarket Roms use a variant of the Later Roms that have been tailored to fit the Car Options added.. And it will fit any of the 8 Bit year ECUs with or without IAV's as they just dont turn on the IAVs.. So if you have a 90/91/92 and have AIVs, the 'Chipped Rom' you put into the ECU, will cause your car to Idle Closed Loop, no AIVs.. So likely your ECU is not getting the 'Idle Switch' feedback from the TPS Switch.. I have an ECU that I pulled off a car that did not idle properly.. it ended up the ECU was getting the Idle Switch Wire Signal, but the ECU did not actually see it in the hardware.. The Conzult Software should be able to show you if the ECU is actually seeing the Idle Switch.. The 'Book' will say the TPS 'Voltage' should trigger Idle Circuit if the Switch should fail.. I've seen that not work as described.. The ECU I changed is an example of it not working.. Check your Switch on the Conzult.. that would be the place to start.. Cj
|
