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Dominicano
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1,698 Posts
Discussion Starter · #1 ·
272 cams.
1200cc injectors.
AEM V2.
Iac system still active.

What is a good AFR for idle at 1k rpm?

What is a good AFR for break in?

What is a good idle fuel pressure at 1k rpm?


My AFR at idle right now is at 11.xx AFR, but everytime i attempt to take away fuel the car jumps in idle and revs higher. How can I bring down idle back down
 

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Buy a Haltech ....lol jokes .
 

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Not sure which injectors you are running, but I find it very hard to get below 13:1 AFR with my precision 1000cc injectors. I know the I.D. injectors are linear and supposed to help with this, but I can't justify the cost. I am also running 272s now. Even though my AFR is pretty rich for idle, my base fuel pressure is only 28psi. If you can get a 14.7:1 AFR idle, I say go for it. I wish I could, but the precision injectors become unstable below 1.2ms so that's where I have to stay.
 

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Something is wrong. With most cars I have no problem running a 14:1 air:fuel with Precision 1000cc injectors and 272 cams.
 

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Dominicano
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1,698 Posts
Discussion Starter · #6 ·
Not sure which injectors you are running, but I find it very hard to get below 13:1 AFR with my precision 1000cc injectors. I know the I.D. injectors are linear and supposed to help with this, but I can't justify the cost. I am also running 272s now. Even though my AFR is pretty rich for idle, my base fuel pressure is only 28psi. If you can get a 14.7:1 AFR idle, I say go for it. I wish I could, but the precision injectors become unstable below 1.2ms so that's where I have to stay.
Could a high base fuel pressure be causing this... at 1k rpm I have it set at 50 psi, i never really touched it out the box as I never knew a good pressure to set it at

Something is wrong. With most cars I have no problem running a 14:1 air:fuel with Precision 1000cc injectors and 272 cams.
Hey im running RC 1200's in my car but for the life of it can i get this thing to idle with a 14afr idle its always between 11 and 12.

ALPHA I know I wanna get you up here, but I want to break the motor in and make sure its actually good for dyno sessions.
 

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Could a high base fuel pressure be causing this... at 1k rpm I have it set at 50 psi, i never really touched it out the box as I never knew a good pressure to set it at
nope...if you noticed, I'm actually running on the low side at 28psi base. Not sure what else I can do...but I don't wanna thread jack.
 

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i'm an absolute beginner/hack of a tuner, but why not unplug the IAC so your not getting any airflow through it, and start winding the screw on the throttle body out to shut the throttle blade more. do it all while the motor is warm with no load on it, getting it idling nice, then plug the IAC back in

*make adjustments to fuel as you go to keep the motor idleing where you want it*
 
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