A/C Idle up rpms for 1uz swapped Cressida

[88sogreatv8]

I have this 1uz swapped cressida and it has a 95 ls400 engine

I merged the factory condensor and drier , with the ls400 compressor , and the a/c blows cold. My issue is when coming to a stop the idle is super low so the alt stops charging and, when hot sometimes oil pressure drops to nothing.

Has anyone found a solution in regards to achieve a higher idle with the a/c on . I know the lexus has a separate computer that triggers the idle up in the ecu. the cressida does not. I tried to wire in a evap solenoid with the power from the a/c clutch, it did idle a little higher but not enough.

any suggestion would be much appreciated Thanks

 

[gloverman]

Maybe the solution is to wire the air conditioning circuits into the uz ecu like it was on the ls400. Well that's how I do them anyway, I copy toyota.

 

[88sogreatv8]

Maybe the solution is to wire the air conditioning circuits into the uz ecu like it was on the ls400. Well that's how I do them anyway, I copy toyota.

So i got to thinking about what you said real hard last sunday , and after reading the wiring diagrams for the ls engine i noticed there was a pin #13 on e11 connector that is tied into the mg clutch circuit on the factory lexus. I had previously de pinned that #13 e11 not knowing what its purpose was. I know now or i think i understand its function .

I believe the #13 pin receives signal when the mg clutch circuit is energized, thus telling the ecu to idle up the engine to compensate the load. ( def correct me if i am wrong. ) i will say when the car is cold and the a/c is on it idles up perfectly now, but when warmed up . it still idles very low. not as low as before , but in the 500-575 rpm range.

I do wonder if this lower idle has anything to do with the fact that all of my egr evap stuff is deleted /blocked off . all the vac solenoids are removed also

 

[88sogreatv8]

i also have a bit of a leak on my brake booster also

 

[gloverman]

So i got to thinking about what you said real hard last sunday , and after reading the wiring diagrams for the ls engine i noticed there was a pin #13 on e11 connector that is tied into the mg clutch circuit on the factory lexus. I had previously de pinned that #13 e11 not knowing what its purpose was. I know now or i think i understand its function .

I believe the #13 pin receives signal when the mg clutch circuit is energized, thus telling the ecu to idle up the engine to compensate the load. ( def correct me if i am wrong. ) i will say when the car is cold and the a/c is on it idles up perfectly now, but when warmed up . it still idles very low. not as low as before , but in the 500-575 rpm range.

I do wonder if this lower idle has anything to do with the fact that all of my egr evap stuff is deleted /blocked off . all the vac solenoids are removed also

Not sure on your understanding of the wiring however E11 Pin 13 is ASMG which is not an input at all, its an output to trigger the air conditioning relay which triggers the magnetic clutch. If you have fed power into this wire you might want to check the condition of the ecu now. If you did an earth trigger is unlikely to have done damage. A20 is the input for the air conditioning into the ecu, The ecu then does its idle thing, and then triggers ACMG.