Mods: Headers, CAI, 1.6rr.

At idle BLMs go to 160. Part throttle throttle BLMS drop to mid 150s. WOT they go to 140s. WOT O2 values = mid/low 900mvs.

Does this indicate an exhaust leak (possibly the slip fit on the headers), or is this a tuning thing I need to correct. Car runs perfect (no hesitation, no misses). I have LT1 edit, but know very little about tuning. Any pointers on where to start?

Cliff's notes: Mechanically the car seems perfect. How do I get the blms closer to 128?


Ryan

 

Sounds like you need to adjust your inj. constant since your so far off from 128...

Cody

 

What is it doing in open loop?

What I did when I had my heads and headers done is this:

I was running a rich condition (BLM's at 108) and could not figure out why. It was suggested on this board that I adjust my MAF tables. I reduced (remember I was running rich) what my MAF was reading via the MAF tables by 15% - call it variance - up to about 15 gms. I reduced that initial variance slowly until about 100 gms where I met up with the stock MAF numbers. This put me right on for my BLM's. By reducing what the computer saw as gms, it added less fuel to try and maintain stoich.

Obviously you would be the opposite and you may have to adjust the whole table not just parts like me.

Now if there are other issues that we are not aware of such as 02's being way off from each other, this issue comes and goes, etc. you could have something else.

However, if you want to try it, give me an e-mail and I will attach back my Excel spreadsheet I used to make my adustments.

Ben

 

Thanks for the info guys.

Ben, you've got mail!

Thanks! Any other suggestions?

Ryan

 

No mail!


Try again!

Ben

 

AOL + me =

Sorry. Sending another from the AOL AND yahoo accounts. Please reply to the AOL account. Thanks man!

Sending to: irentat@***.net

Ryan

 

Just to update everyone...

The car had a GTP ported intake on. I had installed it because I had to exchange for a core. After finally getting a stock intake on my BLM issues went away. The ports on the intake were larger than the head's. I'm assuming this is what made the BLMs whacked out.


Ryan

 

Without knowing what mods have been done since it ran without split BLMs, this is all a worthless guessing game.

If you have headers/CAI and 1.6 rockers like you say, injector constant has nothing to do with the problem, and sounds much more like an exaust leak. What side is this on, or is it on both sides of the car?

Larger intake ports on the intake than the heads, is not a good thing. That will block AF from getting through to the head properly, essentially anti-reversion in the wrong direction.

 

I had forgotten about that intake being a 'mod'. Probably because I didn't consider it a speed mod, although it obviously would effect atomization. While both banks were affected, one side about 10 blm counts leaner than the other.

Before I swapped the stock intake back on, I changed the MAF table a little bit and almost had the issue under control. Ofcourse once the stock intake went on the BLMs were extremely low, so I knew right then what was up the whole time .