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the MAD scientist
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2,574 Posts
Discussion Starter #1
Well I finally got my turbo on the car so I went for a short drive around the block, without boosting. I noticed my AFR’s are extremely erratic.

For fuel all I have is a chipped ECU running an uberdata basemap with closed loop enabled and RC 440 injectors. Smooth idle, no vacuum leaks, no CEL’s or anything.

Cold start AFR is about 11.9 and slowly rises to 14.7 when it’s warm after about a minute or two, which seems normal

But when cruising the AFRs jump around like crazy from 12-17, depending on load. Most of the time they seem to be around 15-16, which seems way too lean. Sometimes at very low throttle angles it will read DEAD LEAN (WB says air).

I’m thinking I should make another ROM disabling closed loop in hopes of making the AFR less jumpy.

Anybody have any suggestions? I’m definitely a noob at tuning so somebody please help!!
 

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the hard-parker
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4,257 Posts
if you have a wb, datalog it and check to see what values it's giving you. i'm not exactly a veteran at tuning, but i know if it were me, i'd run a datalog and check to see what the values on the table looked like.
 

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the MAD scientist
Joined
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2,574 Posts
Discussion Starter #3
Well I didn’t have time to set up the datalogging but I burned a few different maps changing the vacuum columns and got the AFRs in a range where I wanted them.

The strange thing is now it seems to idle a little weird. I have a small vacuum leak in the BOV so I’m gonna grease up the piston to see if that seals it better.

I’ll keep ya’ll posted. Boost is very fun BTW!!
 
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