Disappearing IAC counts

[XfireZ51]

Seems like I finally slayed this dragon. While tuning Pete's cams, I would notice that my IAC counts would drop at idle. It would start out at about 25 or so and then drop with each successive stop and as the motor warmed up. Finally it would go to 0. However the idle would remain stable considering the larger cams with idle in the 875-925 range. I thought to check the TB and found a tear in the airhorn gasket. repaired that but still lost IAC counts progressively. Finally I started to hear a faint whistling from the left side and I was able to determine it was a vacuum leak at the #2 primary injector. Pulled the plenum, but what I found was that the fuel rails were not securely bolted down. In fact, one of the bolts had dropped down to the valley. Finally straightened everything out today, and took it out on a hot day. IAC counts started high but then progressively dropped but then they stabilized at 28. A bit high for my preference but at least stable. From there, I could re-set the Min Air and now its at about 10-15. I'll re-scan to check but it idles at 875-900. I re-did the VE table and took out fuel since the leak was leaning things out. Just installed new calibration and will datalog again tomorrow to see if BLMs are closer now. Did some smoothing w VE and you can feel less choppiness to the throttle transitions.

[scottfab]

Another loose fuel rail. That's two in a week.
I'll be checking mine this week.
I also will be using a remote camera to fish inside
the V to look around. Who knows what I might
find in there.

Not that it matters but which end of which fuel rail
was loose?


Scott,

It appears that I must have put in the bolts but never torqued them down. Perhaps got distracted. And then I put plenum on. Left side had both bolts in but loose.
Right side had front bolt in and back bolt fallen in the valley.

[Blue Flame Restorations]

I had something happen yesterday that had never happened before. When I would sit at a stop light, I could feel and hear the idle drop momentarily. Almost like it was going to die for a moment but never did. This happened at any stop light that I had to sit at.

IAC was replaced a month ago.

[XfireZ51]

I had something happen yesterday that had never happened before. When I would sit at a stop light, I could feel and hear the idle drop momentarily. Almost like it was going to die for a moment but never did. This happened at any stop light that I had to sit at.

IAC was replaced a month ago.

Did fans kick in?

[Blue Flame Restorations]

Did fans kick in?


Not sure. Car is so loud, it's hard to tell. I'll drive it tomorrow and see if I can hear them.