Lean at idle

Lou02stang

Member
Established Member
Joined
Jan 13, 2016
Messages
48
Location
Brooklyn
I am working with a prominent mail order tuner and having problem with idle. My STFT is .75 on bank 1 and bank 2 during 2 minute datalog. My innovate wb is at 22.4 if I hit the gas to say 1700rpm it drops to like 16. Tuner added fuel about 4 times by multiplying MAF transfer table by 1.3 but still runs lean at .75. On the last datalog about 1:30 min into log the STFT jumped to 1.03 bank 1 and 1.25 bank 2. For like 8 seconds and then back to .75. My setup is a 2001 2v with a MMR 750 4.75 shortblock ported heads stage 2 CMS turbo cams single FF On3 with a Precision 7675 any help is appreciated I also have the datalog if needed. Thanks
 

01blckcobra

Active Member
Established Member
Joined
Sep 5, 2009
Messages
314
Location
Wisconsin
Can pm Decipha, 04sleeper

or visit

EFIDynoTuning

More than likely get better results from people if you post a datalog. lot of variables.

What MAF / injectors / fuel system using/ E85?

What's the LTFT? Commanding .75 at idle?
 

96gt02

Well-Known Member
Established Member
Joined
Jan 21, 2015
Messages
1,465
Location
NJ
A STFT of .75 would indicate that your running 25% rich not lean. 1.25 would be 25% lean
 

01yellercobra

AKA slo984now
Established Member
Joined
Oct 5, 2005
Messages
21,128
Location
Cali
What's the rest of the set up? Pumps, injectors, returnless, etc. How aggressive are the cams? An aggressive cam can be a pain to work with. My suggestion would be to force open loop and see how it reacts at that point. If the A/F evens out then the tune needs more tweaking. If it stays the same it's time to start looking for a mechanical issue.
 

Users who are viewing this thread



Top