Sliding IAC counts...

[Paul Workman]

Got the Z running again, but an old puzzle remains present & unsolved; in spite of new gaskets all round ('cept the TB gaskets which were changed earlier this year) with no change in characteristics.

What it is...

On startup and the engine is cold, my IAC counts are in the 20s, but after it is fully warmed up and especially if it has been at or close to 7k+ rpm, the counts drop to zero.

Anyone else notice IAC counts changing as the engine warms up?

P.

[XfireZ51]

Got the Z running again, but an old puzzle remains present & unsolved; in spite of new gaskets all round ('cept the TB gaskets which were changed earlier this year) with no change in characteristics.

What it is...

On startup and the engine is cold, my IAC counts are in the 20s, but after it is fully warmed up and especially if it has been at or close to 7k+ rpm, the counts drop to zero.

Anyone else notice IAC counts changing as the engine warms up?

P.

Yes. They will change w Temps. If they're too low, try setting
Min Air on TB.

[Paul Workman]

Yes. They will change w Temps. If they're too low, try setting
Min Air on TB.

Ah! Then I'm not kaaraazee! (Well, mebbe a little;) Thanks for that tidbit, Mr Dom. As a matter of fact, I DID tweak my min air - thinking it might solve my occational decel stall issue. I'll wait till she's fully warmed up and tweak it back down, maybe a 1/4 to 1/2 turn - just enough to have IACs around 5 to 8 ish when hot. That may be at least a work-around. Per Marc's suggestion, I'm going to do an experiment with the TB secondaries to see if they are contributing a little to the amount of swing I'm seeing. If they're OK, then I'll just shrug and be happy with the reset min air screw.

Other than that, she's runnin' real fine - or as before, at least. Still have to figure out the tweak to eliminate the occasional hot-decel stall thingy. But, that's a post for another day....

Thanks, Dom. I'll let you know how that works.

P.

[XfireZ51]

The secondary butterflies shouldn't be an issue unless they need to need to be cleaned. The 0 counts indicate too much air without need for IAC bypass. Assuming no other leaks, the min air and clean TB blades would be my suspicion. And yes adjust the min air for hot engine. In fact, I adjust it w motor running and just after fans shut off.

[Paul Workman]

The secondary butterflies shouldn't be an issue unless they need to need to be cleaned. The 0 counts indicate too much air without need for IAC bypass. Assuming no other leaks, the min air and clean TB blades would be my suspicion. And yes adjust the min air for hot engine. In fact, I adjust it w motor running and just after fans shut off.

Set while running. Hmmmm (glad I thought of that;)) Good tip. Thx, Dom.

P.

[XfireZ51]

Set while running. Hmmmm (glad I thought of that;)) Good tip. Thx, Dom.

P.

Its a bit of a bitch to do unless you replace set screw with one that has hex head. Ask Pete or Marc about which to use.