Wrong Ecu in car. Side effects ?
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Wrong Ecu in car. Side effects ?
Recently found out my 95 sc400 had a 92-94 California ecu. My sc is non-Cali. Just wondering what this could do to my car. Would it tinker with stuff or would it just be okay? Car is having idling problems as of right now. Going to replace ecu with a 95 one. Just wondering if this could be the very culprit for my problem. Or nah. Lol
#5
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Simply yes, that is your problem those sc400 ecu's are not compatible. its not like a sc300 at all.
sc400 received quite a few changes in 1995 including becoming an inteference engine and an updated ecu/harness.
95 sc400 uses sequential injection meaning it has 6 wires one for each fuel injector.
92-94 sc400's use batch fire injection meaning there are 3 wires for 6 injectors and 2 fire at a time.
So when you use a 93-94 sc400 ecu on a 95 sc400 harness... you get half the cylinders getting fuel.
let me guess its idling at about 350-400rpms and feels very sluggish like its on 4 cylinders... well that is because it is running on 4 cylinders right now.
Yes you need a 95 ecu. you cannot use a 96 ecu because it is obd2. you specifically need a 1995 Sc400 ecu, non cali preferably.
sc400 received quite a few changes in 1995 including becoming an inteference engine and an updated ecu/harness.
95 sc400 uses sequential injection meaning it has 6 wires one for each fuel injector.
92-94 sc400's use batch fire injection meaning there are 3 wires for 6 injectors and 2 fire at a time.
So when you use a 93-94 sc400 ecu on a 95 sc400 harness... you get half the cylinders getting fuel.
let me guess its idling at about 350-400rpms and feels very sluggish like its on 4 cylinders... well that is because it is running on 4 cylinders right now.
Yes you need a 95 ecu. you cannot use a 96 ecu because it is obd2. you specifically need a 1995 Sc400 ecu, non cali preferably.
Last edited by Ali SC3; 10-27-14 at 12:47 PM.
#6
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Simply yes, that is your problem those sc400 ecu's are not compatible. its not like a sc300 at all.
sc400 received quite a few changes in 1995 including becoming an inteference engine and an updated ecu/harness.
95 sc400 uses sequential injection meaning it has 6 wires one for each fuel injector.
92-94 sc400's use batch fire injection meaning there are 3 wires for 6 injectors and 2 fire at a time.
So when you use a 93-94 sc400 ecu on a 95 sc400 harness... you get half the cylinders getting fuel.
let me guess its idling at about 350-400rpms and feels very sluggish like its on 4 cylinders... well that is because it is running on 4 cylinders right now.
Yes you need a 95 ecu. you cannot use a 96 ecu because it is obd2. you specifically need a 1995 Sc400 ecu, non cali preferably.
sc400 received quite a few changes in 1995 including becoming an inteference engine and an updated ecu/harness.
95 sc400 uses sequential injection meaning it has 6 wires one for each fuel injector.
92-94 sc400's use batch fire injection meaning there are 3 wires for 6 injectors and 2 fire at a time.
So when you use a 93-94 sc400 ecu on a 95 sc400 harness... you get half the cylinders getting fuel.
let me guess its idling at about 350-400rpms and feels very sluggish like its on 4 cylinders... well that is because it is running on 4 cylinders right now.
Yes you need a 95 ecu. you cannot use a 96 ecu because it is obd2. you specifically need a 1995 Sc400 ecu, non cali preferably.
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#9
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usually its just codes for the heaters missing on the o2 sensors and other minor differences none that would cause it to idle like that. what was it doing before the ecu was changed?
that is usually a sign of a iacv issue or tps issue or an air leak.
also I just noticed that you said you just figured out about the ecu, which means you didn't swap it.
SO... There is a very good chance someone not only changed the ecu but the entire harness and motor to the more available 92-94 kind. If that is the case then you would not want to use a 95 ecu. you will want to use the ecu that matches your harness or it won't run right.. so you might have the ecu you want already if that makes sense.
theres no quick way to tell short of pulling the connector off of the ecu and seeing how many injector wires there are. if 4, 5 and 6 are missing you have an old harness and should keep the older ecu.
that is usually a sign of a iacv issue or tps issue or an air leak.
also I just noticed that you said you just figured out about the ecu, which means you didn't swap it.
SO... There is a very good chance someone not only changed the ecu but the entire harness and motor to the more available 92-94 kind. If that is the case then you would not want to use a 95 ecu. you will want to use the ecu that matches your harness or it won't run right.. so you might have the ecu you want already if that makes sense.
theres no quick way to tell short of pulling the connector off of the ecu and seeing how many injector wires there are. if 4, 5 and 6 are missing you have an old harness and should keep the older ecu.
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