Im going CRAZY, WOT tuning is being a bastard! Running out offuel

[Ernst denBroeder]

I have the same problem with my 2.8tbi, goes lean at 4400rpm.  I too have
played with the fuel tables to no gain...  but before going to the list, I
wanted to go over the fuel system first.  I have many no-no's like old
fuel pump, filter and injectors.  Too many unknown's before blaming the
computer in my case.

Ernst denBroeder


On Thu, 25 May 2000, olbap wrote:

> 
> It runs strongest at about .9v, currently thats dropping down to very low
> .8's and high .7s wot.. it runs absolutely horrible too, and im getting
> pretty bad knock when it happens.
> 
> The more I think about it the more im starting to think heat is causing it.
> Not coolant temperature but just some automotive component heat soaking.
> The reason I believe this is because the last time I went to the track, it
> did the same thing. I issumed it was bad injectors because the track is 150
> miles away. I figured the ecm would have learned pretty much all there was
> to learn. I ran my fastest time on my first run, each run was progressively
> slower and slower and when i finally decided to look at my O2 it was down at
> .4 - .5 wot at the end of the night!
> Yes, i have kept copies of each bin as i go and have taken mental notes. As
> I said before, i think my part throttle is very close to being right.
> 
> Pablo
> 
> 
> 
> 
> 
> At 08:08 AM 5/25/00 EDT, you wrote:
> >Pablo,
> >you didn't say what your O2 readings are.  When chip tuning, always
> >take notes, and keep copies of each bin as you go, so you can "go back".
> >If you think the ECM's learning curve is fighting you, kill the power
> >to the ECM and make another test run.. You didn't mention what you 
> >are using to gather data, but I would think the integrator numbers should
> >help you tun the fuel...
> >MV
> >
> >> 
> >>  I start tuning WOT this morning, friend (or shall i say carbureted arch
> >>  nemesis) comes by, first chip it runs very strong.. lean past  4200 but 
> >very
> >>  strong nonetheless,  he thinks  i might give him a run finally... he leaves
> >>  afterwards.
> >>  
> >>  So, I go into my AFR- WOT table.. drop it down some at 4800   
> >>  
> >>  Go for a spin again.. runs much better.. still lean a bit on top
> >>  
> >>  Repeat step two
> >>  
> >>  Go for spin again, seems like maybe (this is a shot inthe dark)  perhaps my
> >>  part throttle isnt as good as i thought, on therich side, and the ecm is
> >>  leaning me out across the board
> >>  
> >>  Ok, ill just keep richening it up till its beyond the scope of adjustment i
> >>  figure (yeah im real half assed about things, i just want it to be fast at
> >>  wot at this point)
> >>  
> >>  Repeat step two.. several times
> >>  
> >>  repeat thepart about me going lean several times.. yet getting worse
> >>  andworse each time... down to about 3800 rpms its pretty much done.
> >>  
> >>  Ok, time to go crazy, so i start making big changes in the AFR and FL2 just
> >>  to make it  bird killing, rear bumper blackening, plug fouling rich (id
> >>  rather work down than up)
> >>  
> >>  ok, it only makes itBARELY better than what it was
> >>  
> >>  at this point, i think a geo metro can beat me
> >>  
> >>  
> >>  desperate times call for desperate measures so i repeat the bird killing,
> >>  plug fouling step
> >----------------------------------------------------------------------------
> >To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
> >in the body of a message (not the subject) to majordomo at lists.diy-efi.org
> >
> >
> >
> 
> ----------------------------------------------------------------------------
> To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
> in the body of a message (not the subject) to majordomo at lists.diy-efi.org
> 
> 

----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org