IAC at WOT

[Warped]

What should the IAC numbers look like at WOT?

 

[Steve Wood]

It is called an Idle Air Control valve for good reason. It has no function at wot.

 

[Warped]

The reason I asked is I was looking at DS data for two cars and on one at WOT the IAC reading was 77 and the other was 103. The IAC is obviously flowing something at WOT but I have no idea what the range of the device is or how much air would flow through the IAC at 103. What I'm really wondering is if the IAC number at WOT might indicate the car is running rich and the IAC is working to compensate. Why else would the two numbers be different? Just looking for another tuning aid.

 

[tazgn]

I would think it's probably the chip, or maybe just where it happens to end up on those runs. I run the FAST DFI system and have my IAC set to be wide open at greater than 50% throttle. It probably just doesn't matter, but it can't hurt getting every little bit of air into the motor at WOT. But when off idle, I don't believe the IAC numbers mean a thing.

Derrick

 

[Warped]

Thanks.

 

[speedy1320]

IAC

OK......so speaking of IAC.....where should it be at idle?




87 WE-4
3" DP, Exhaust
ATR IC
Chip, thermostat, 14" K&N
36lb inj
Walbro
Hot wire
Adj FPR

 

[TurboDave]

Re: IAC

Originally posted by speedy1320
OK......so speaking of IAC.....where should it be at idle?




87 WE-4
3" DP, Exhaust
ATR IC
Chip, thermostat, 14" K&N
36lb inj
Walbro
Hot wire
Adj FPR

For best results, generally, any value between 5-20 while in park/neutral, on a well warmed up car. When shifting into gear the values of course will increase some to maintain commanded idle.

 

[bruce]

Originally posted by Warped
What should the IAC numbers look like at WOT?

Typically anything from 70 to 170,
depends on the chip.
Off idle it serves as a throttle follower, so the rpm can't drop too quickly, when you back off the gas, or stall, all bad for emissions ya know..

 

[bruce]

Originally posted by Warped
The reason I asked is I was looking at DS data for two cars and on one at WOT the IAC reading was 77 and the other was 103. The IAC is obviously flowing something at WOT but I have no idea what the range of the device is or how much air would flow through the IAC at 103. What I'm really wondering is if the IAC number at WOT might indicate the car is running rich and the IAC is working to compensate. Why else would the two numbers be different? Just looking for another tuning aid.

On the GNs you can use it for a drivibility aid, kind of tricky thou. It is the choke, and throttle follower.

On a N/A car you can get some HP with larger counts, not on the GNs.

There is no tie in from IAC to AFR, other then as a secondary effect.

I use a high limit of 24 for all the IAC counts, but it takes work to do that. Hint: 10 or lower and the ecm can get confused. All the accleration enrichment needs tweaked since you need less since the IAC isn't bleeding so much air during transistions.

 

[S10xGN]

Speaking of IAC motors: have any of you ever tried electrically "stroking" one of these out of the housing? I tried moving the pintle using the diag terminals of the ALDL and the dange thing flew apart! I tought there was something wrong with it, so I tried it on my spare and it flew apart too! How do you get the pintle to move back into the housing???

 

[Mr URL]

Originally posted by S10xGN
Speaking of IAC motors: have any of you ever tried electrically "stroking" one of these out of the housing? I tried moving the pintle using the diag terminals of the ALDL and the dange thing flew apart! I tought there was something wrong with it, so I tried it on my spare and it flew apart too! How do you get the pintle to move back into the housing???

Yes, it will! Don't try this at home.

 

[Steve Wood]

Several of us May have tried this at least once... LOL

 

[bruce]

Originally posted by S10xGN
Speaking of IAC motors: have any of you ever tried electrically "stroking" one of these out of the housing? I tried moving the pintle using the diag terminals of the ALDL and the dange thing flew apart! I tought there was something wrong with it, so I tried it on my spare and it flew apart too! How do you get the pintle to move back into the housing???

There are several hobby kits for making stepper motor controllers, they cost about $20. Throw away the motor they give you and install a large cap to slow the driver down, install a IAC connector and then you can play all day shooting them across the room and reloading them.

Be advised sometimes it'll scare the cat.....