My 2004 STI JDM ticks over at 500rpm which is no problem until at night when the lights and heater etc are on and then when the radiator fans kick in it starts hunting and the revs wont settle until i turn the heaters off. The car never stalls though! What can i do to solve this?

 

500 seems low anyway tbh

 

i thought that! When i get it mapped was wondering if it could be sorted then?

 

As far as I know there is only a small amount of adjustment through the ecu.

Whether it would be enough I don't know, could be an underlying problem causing the issue though

 

There is no EML on and it only does it when the fans kick in. when in the daytime it sorts itself out ok but at night it plays up. The car runs spot on otherwise and only has 35k on the clock

 

Mines an 03 blob STI type uk iirc my local specialist said he could adjust the idle through the diagnostic tool by around 300rpm, it was a while ago now though lol.

My idle was all over the shop due to a knackered IACV.

Is your alternator in tip top condition?

Mick

 

il get my mate to test the alternator at work. Did you change the valve as well?

 

I tried all sorts mate as it was idling all over the place when cold but once warmed up it was settling down, I changed plugs, coolant temp sensor, MAF meter, cleaned my IACV and then finally bought a used one off here and hey presto the cheapest easiest part to change fixed it lol.

Mine was throwing the EML light on though and storing a code.

As far as I know you'll have to test the alternater while its under load ( lights, heaters etc ) as it's some sort of tricky smart charging alternator.

Mick

 

Nice one. Its getting MOTed next weekish so it can be checked over then!