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wozza

S13 SR20DET high idle when cooling fan is on

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I'm trying to work out the strange idle behavior of my S13 SR20DET.

 

When the radiator cooling fan turns on at 87 deg the idle goes up from 950 to around 1200+ rpm, and Datascan shows the "closed TPS" switches from ON to OFF, and the timing goes up from 15 deg to 30 deg. When I was in bumper to bumper traffic the other day idle went way up to 2000rpm and only came down when I could gather some speed or if I parked the car and waited for the temperature to drop.

 

I initially thought the FICD was connected by mistake to my cooling fan instead of the AC fan (it's an engine conversion into a Peugeot and I'm not running AC) so I connected some jumper wires between the IACV male and female connector plug and tried unplugging the FICD wire while it was idling high but it made no difference. However when I unplug the ACC wire the revs dropped to 700rpm. This says to me that it's the ACC creating the high revs when the fan kicks in and not the FICD, which is supposed to increase idle when AC is turned on.

 

But how does the ACC/ECU know that the exact second the cooling fan has kicked in? And why does it take the TPS off "closed TPS"? Could it be a problem with the "wax pellet" in the IACV which controls cold idle?

 

TPS and timing have been set at factory settings, new coolant temp sender installed and car idles fine if a little high at 950rpm when "closed TPS" is showing ON. I can't seem to get a lower idle than 950rpm though even going through the factory idle procedure. Any ideas?

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Ok that makes sense but why 2000 rpm? Is that just a malfunctioning ACC? And wouldn't that be the job of the FICD which turns up the idle when the AC is on?

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Just tried turning on lights, heater fan,wipers and indicators all together. Idle temporarly increases around 100rpm then settles back to std 950rpm.So i reckon its not the electrical load.

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I spoke too soon Dose pipe. I hooked the datascan back up to the ecu and the headli ghts and fan DO take the TPS off closed and off normal idle. Sorry. And i think my 2000rpm idle might have been caused by my power steering being low on fluid as it hasnt happened since i topped up the fluid. I had no idea these things affected idle!

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