So even since I MS-1 parallel'd my car and installed my 460's, I got my car to run pretty good. This week it started to idle (fully warmed up) at like 1200-1400RPM. The last time it idled high was because I had a vacuum leak around my injectors due to faulty seals. Since I am parallel'd I can still pass codes. I get codes P0171, and P0172, which are rich and lean codes, and I am not concerned about them. I did, however, get code P0507- idle control system RPM high. I haven't made any changes to my car or burnt anything different to the MS in like 2-3 weeks. Could this be a vacuum leak to the MS? Or maybe a very small leak around the injectors again?

 

what happens if you unplug your IAC?

 

I have the same problem. Haven't been able to figure it out but i've only got one vaccum leak that I can find (TB gasket) and when I put my thumb over it nothing changes. I've just learned to live with it, i'm pretty sure my IAC is toast.

 

I unplugged my IAC and the valve moved, so it is functioning properly. My vac/boost gauge reads 21inHG at idle just as it always did. This is why I think it's a vacuum leak at the injectors. I think it's those little black washer looking seals. Does anybody know the Mazda part number for these things / what they are called?

 

8574-13-257: INSULATOR, INJECTION

 

Thanks, $3.90 a piece. You're the man Joe.

 

Hey are those little isolators (13-257) the same ones used on RX-7's? I slid these on my 460's and they feel really loose, as in, they'd fall right off if I took off my pintle caps, and there is a lot of side to side movement.