Remanned engine first start - Air/Fuel ratio check

[JDUB348]

Just fired up the remanned engine for the first time. At the same time i'm also getting the coolant system all refilled/getting the air out. Any ways, right now the airfuel ratio is sticking around 16.. i don't believe i've let the car get up to a 100% warm idle yet, so could this be the issue? I believe your suppose to be right around 14.5 correct (feel free to correct me on that)?

Oil pressure is good. It's still up to around 75PSI right now, which from what i can remember isn't the full operating temp pressure (being it will be lower at idle at full operating temp)?

Does a brand new engine have to run for a little while to get to the desired "normal" air / fuel ratio?

 

[Cobra03SC]

It may have to run to let the maf/02s learn, check for small exhaust leaks also that may be throwing it off alittle. 16 isnt going to hurt anything just idling.

 

[DannyBoy08]

Similar to the above response, don't cars use an ECU program to do air-fuel mixture at startup, then convert to MAF when warmed up and operating with decent airflow? I'm no expert, but that's what I had always known to be the case anyway.

 

[JDUB348]

After driving it for a little bit (babying the hell out of it keeping it under 3,000 rpm) the air fuel ratio still stands around 16 at idle. I sent an email off with a datalog to my tuner to see what he thinks.

 

[DSG2NV03]

I can take a look at the datalog if you would like. [email protected]

 

[Parts-is-Parts]

Check for leaks in the exhaust. It only takes a small crack

 

[93stang5.0]

So, besides the new motor mods have not changed?

 

[JDUB348]

So, besides the new motor mods have not changed?

No sir, nothing what so ever. I'm suspecting an exhaust leak could be the cause, as i think i was hearing a leak as i was driving down the road. Will have to jack the car up next weekend and check it out.

 

[Brutal Metal]

at idle it shouldn't just stay at 16, mine bounces around from low 14's to high 15's..