K20iVTEC

I went to the drag strip last night and after each run my a/f ratio would be 16.4:1 at idle. Normally it's 15.2:1 at idle after it was tuned by Jeff evans. If left to idle it eventually drops back down the low 15's. Never did this on the street. It scared me a little sitting in the staging lanes and seeing numbers I'm not used to seeing. Honestly I didn't look at the gauge while running down the track. Dumb on my part I know but after when i left at WOT it was good right around 13... so my question is why would it idle lean after wot pulls? Thanks for any info!

Mods: custom 3.5" intake, 70mm bored oem throttle body, matched intake manifold, PLM header, 70mm test pipe, hks 75mm single exhaust, ap1 intake cam, kpro

s2000Junky

My 01 OEM ecu will run leaner than this, sometimes to the point of choking the motor with no fuel after I shut it down and go to start after its been sitting for 30+ min. I always chalked it up as heat soak playing havoc on the ecu fuel trim and sensors. It always clears back up to normal after a min or so. In your case, being at the drag strip, engine hot, shutting down, starting back up multiple times, that a similar thing is going on. Running lean at idle with no load isn't going to cause any harm to the engine. Its when your too lean and you are putting load on the engine which is a problem for concern.

Keep track of what its doing though and get a sense of the pattern and if it changes.

flanders

Some temp compensation table that's a bit off maybe?

s2000Junky

Probably. Not uncommon at all after a tune. cant replicate everything on the dyno, and so its a educated guess a lot of times from the tuner.

OP, find the table for your idle fuel for coolant and AIT and add a little fuel if it bothers you. make sure your not correcting your normal idle temp tables.

K20iVTEC

Great info guys thanks! Good to know that i wasnt hurting anything. I'll just contact my tuner and try to send him a datalog. I don't want to mess with anything myself... thanks again!

K20iVTEC

This morning it was pretty chilly around 50 degrees. Under wot I noticed a/f gauge starting around 13.2 and ending up around 15.6 toward redline... when i got tuned it was 90 degrees and very humid. This seems to confirm that a temp correction table is off. Haven't contacted my tuner yet because my only issue before was at idle under very hot conditions. I haven't been in that situation to record a datalog so tonight when it gets colder again I'll go out and get a datalog and email it to him... hopefully it's an easy fix and I don't have to drive the 4.5 hours back down to PA to see him....

flanders

With those numbers I wouldn't run it towards redline again without adding som fuel first.

K20iVTEC

What are the chances I'm running out of injector duty cycle? I'm making 240whp... I know with my rsx I ran out at 230whp... if I remember correctly they are close ib size 310 vs 360? I need to do a datalog

flanders

There is also much higher drivetrain loss on a S2k so you could be close, a quick log will tell.

s2000Junky

The stock 360 Injectors are retained for the stage 1 supercharger which makes 300whp. The duty may be getting near, but you have a lot of room left if you increase the fuel pressure. I run about 85psi static on my N/A set up with stock injectors. This is to compensate for factory duty however, so you wouldn't need to run that high if you do decide to add a adjustable fpr. Good chance, you just need to recal your fuel tables. You do have the option of upping the pressure though if you need, if you don't want to invest in new injectors and more time tuning once again.