i just picked up an 87 turbo II... but the i dle is jumping from 500 to 600 after it warms up...i turned the BAC valve counter clockwise 360x2 but it didn't do jack. shouldn't this do something? there is also another valve (i'm not sure what this one is called...its right beside the pressure sensor near the intake) i turned it all the way clockwise and the idle kept steady ...that was yesturday now today after installing a blitz bov its acting up like before. what should i try now

 

ok the "other valve" is the variable resistor. i looked on the manual and i'm wondering what do they mean by "connect a techometer to the engine" ?

 

That is to adjust idle mixture. You need to jump a wire and turn the idle speed (BAC) up then adjust the mixture than turn down the idle speed. You need to get a tachometer to properly adjust it. Hope that helps.

 

Also, the Blitz BOV (and many others) tends to leak vaccum at idle. I had one before and my car ran funny with the BOV. I found the BOV was to blame and removed it. Something about open atmosphere blow off valves and Airflow meters. Personally, I had no problems with Apexi's blow off valve on my old T2. Right now, I'm waiting for a Greddy BOV. The thing about Blitz, especially when its used, is the adjust screw tends to leak vaccum. Teflon tape could fix it a little bit. I'm pretty sure someone on this forum had the same problem. Hope that helps.

 

adjustable FPR's have the same problem, switching to a speed/density ecu (most standalones) solves this, as there is no MAF/AFM in this setup, it doesnt care where the air comes from.

 

well i didn't know about jumping the set plug thing...which i just tried but the bac still didn't do jack. i had it almost pulled out...counter clockwise...btw where do you get the tachometer from anyways? also is it ok to run rich as possible on the mixture valve? and about the bov...it had this problem before the blitz blow off valve.

thanks

 

have you tried adjusting your throttle position sensor

 

guys...i figured out the problem the bac valve connection to the ecu was bad...the connector and the wires were basically fried. so i went to the j-yard and found the plug with the wires and i soldered it on and set it like the fsm says and its good to go!! thanks everyone for ur help!!