I didn't realize my A/F would be THAT messed up!!!

Just picked up my baby after installation of S2 Heads, TR 224 cam 112 LSA; other mods in my sig.

JESUS <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

Sounded like Orville Red 'n' Bacher in my engine when I layed into the throttle a bit <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

With my MAFT set at 15% rich base 0 WOT, my O2's averaged .651 and +2.15 LTerms <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> Applied the throttle (not even near WOT) and popcorn at the movies <img border="0" alt="[whiner]" title="" src="graemlins/gr_cry.gif" /> The mech told me with my intake wide open: TB, MAF, Lid, etc. I needed a LOT more fuel (this I already knew . . . just didn't know it would have this SERIOUS of an effect).

I multiplied my PE rpm value by 120% and kept the MAFT at 15%; O2's .501 and LTerms at +1.65 <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> no popcorn this time <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

My timing at idle was ~14* . . . that sucks.

Didn't do a WOT tap yet, I'll wait 'til Friday night.

The above readings are confusing the crap outta me <img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" />

Any help guys?

 

You might want to read up on tuning a bit, I have no idea why you're checking your O2s at cruise (only time you care about is at WOT), or why you're checking your timing at idle (???). You can get a good idea about your ltrims when you are in certain fuel cells (don't remember off the top of my head), but it only involves checking when you're on the gas, not deaccel or idle or wot. You'll get lots of different values, so you have to average them out. Negative a couple, on the ltrims, is about where you want it. Depending on your year you'll want to be seeing mid or high 20s for timing at WOT (at high rpm), and high .800s/low .900s on the O2s at WOT as well.

This is pretty rudimentry, like I said, you might want to read up on tuning a bit before you start changing all this stuff with your MAFT and LS1edit, when you could be causing serious engine damage.

Dope

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Dope:
<strong>

This is pretty rudimentry, like I said, you might want to read up on tuning a bit before you start changing all this stuff with your MAFT and LS1edit, when you could be causing serious engine damage.

Dope</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Exactly the reason for my query dope.

Pinging in my engine is DEFINITELY a cause for concern.

I do not know how to monitor separate fuel cells (I think I was told #19 . . . not sure about that).

I do know that I won't learn if I don't ask.

Thanks for your help though <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

One other thing: the PE thing . . . I got from a variety of people on this, and other, forums <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

I'm not about to keep it "as is" when my engine is definitely in need of fuel <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Dope:
<strong>. . . Negative a couple, on the ltrims . . . 20s for timing at WOT (at high rpm), and high .800s/low .900s on the O2s at WOT as well.

Dope</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I am well aware of the fact that I want my Lterms to average -1 to -3.

I also know about the timing <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
I referenced my timing issue because before install, my timing was ~19 at idle.

I also know that O2's should average ~880-890 at WOT <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

I'm merely trying to give as much information as possible in order to give a better platform from which to form a diagnosis from more educated members <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

I have no idea what they would need to look at in order to offer assistance.

And, as I mentioned in the original post, I could not go WOT without MAJOR pinging and loss of hp.
Pinging go bye-bye after PE adjustment <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

Thats too confusing thats why I leave the tuning to the pros. <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />

 

Put the tuning/maf back to stock, ditch the MAF translator, and reset the PCM.

What you are describing is *NOT* normal after a heads/cam install, something is wrong. Don't pile on more crap with hacking the tuning just yet, get the car running better first (unless you went with some super high C/R and are using bad gas, which then I guess tuning would be nessisary).

I have been in tons of heads/cam ls1's with stock tuning and not once have I ever expereicened what you are talking about.

Timing at idle? Who cares? O2's at cruise? Um...yeah..they average around 500 because they constantly flip back and forth!#@ <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Before you really mess something up, undo all your A/f hacks and start fresh, or at least, thats what I'd do.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by stang killer:
<strong>Thats too confusing thats why I leave the tuning to the pros. <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have access to dyno-tuning but unfortunately the shop isn't open on the weekends.

They have a wideband O2 and experienced techs but I won't be able to travel to their shop until Monday.

So, between now and Monday, any temporary fixes (or maybe even help on dialing it in before then <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> ) would be welcome <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by jmX:
<strong>Put the tuning/maf back to stock, ditch the MAF translator, and reset the PCM.

What you are describing is *NOT* normal after a heads/cam install, something is wrong. Don't pile on more crap with hacking the tuning just yet, get the car running better first (unless you went with some super high C/R and are using bad gas, which then I guess tuning would be nessisary).

I have been in tons of heads/cam ls1's with stock tuning and not once have I ever expereicened what you are talking about.

Timing at idle? Who cares? O2's at cruise? Um...yeah..they average around 500 because they constantly flip back and forth!#@ <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Before you really mess something up, undo all your A/f hacks and start fresh, or at least, thats what I'd do.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Before the H/C, I had to adjust my MAF with my bolt-on set-up because I was running lean on the stock tune.

I'd imagine that opening it up further with Stage 2 ported Heads and a larger cam would only augment the lean condition.

I'm not arguing the point, merely attempting to understand the logic <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

If air-flow is increased, wouldn't fuel need to be added?

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by The Dragon:
<strong>If air-flow is increased, wouldn't fuel need to be added?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thats what that little round thing called a MAF is supposed to take care of <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> Put a stock maf on, reset the programming, put some good gas in, and go from there.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by jmX:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by The Dragon:
<strong>If air-flow is increased, wouldn't fuel need to be added?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thats what that little round thing called a MAF is supposed to take care of <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> Put a stock maf on, reset the programming, put some good gas in, and go from there.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">So my ported MAF ends are screwin' me up?

If that's the case, I'll throw the stock ends back on tomorrow <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> (it is de-screened, will this have an adverse affect when I reset?)

I always run 93 octane at the same Chevron station.

Are you suggesting I run a higher octane?

Thank you for the information BTW. I was sweatin' when I heard detonation <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

<small>[ December 05, 2002, 12:32 AM: Message edited by: The Dragon ]</small>

 

I don't meant to hijack The Dragon's post, but I have a question while we're on this subject. If you reset your computer, would it throw things out of whack if you did so with the MAFT set to say, 5% rich? What I'm asking is, when I reset my computer should I unplug the MAFT? I reset my computer a few days ago and forgot I had my MAFT on there set to 5% rich.

 

No need to unplug the MAFT when you reset the PCM.

Yes, aftermarket MAF end will lean your mixture just like porting the MAF will. If after going back to the stock MAF you still have major problems I think your problems are more than a simple air/fuel tune.

Moving to Computer Diagnostics and Tuning... <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />

 

If having a ported MAF or ends will lean the mixture, I can't see how the PCM will always get it right with a reset.
If I went to my stocker, I'd be causing a choke right? I want as much of that air as I can get <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> If I need to add fuel, so be it <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

If this were true, why the need for tuners and tuning <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

When I modified my PE, hard acceleration was fine.

I'm gonna do a WOT with the ends tonight and post the tap . . .

 

The PCM will get the CLOSED LOOP operation back to stoic so long as the O2 sensors are working correctly and that the adjustments necessary to do so are within it's capabilities (which are pretty wide.)

The WOT (open loop) mixture will be affected by these closed loop changes but that doesn't mean that the mixture will be completely corrected as it should be. That's why porting the MAF will cause a PERMENENT leaning of the WOT mixture. The closed loop is richened back to stoic but the WOT is still left somewhat lean.

Most of the possible gains from porting a MAF are in the leaning of the mixture and the raising of the timing advance. Not from letting more air into the engine (it's not really much of a restriction once the screen is removed.)

Custom tuning does ALOT more than simply setting the WOT mixture. The timing advance under mulitple conditions can be manipulated, TQ management can be turned off, the rear O2 sensors can be turned off, knock sensors can be made less sensitive, the idle speed can be raised, etc, etc, etc, the list goes on and on.

<small>[ December 05, 2002, 11:19 AM: Message edited by: Colonel ]</small>

 

"I'm gonna do a WOT with the ends tonight and post the tap . . ."

Make sure you've given the PCM time to adjust to the ends or any other changes you've made before doing so. Otherwise the info will later change.

 

After you reset the pcm.Check all of your plugs and make sure that one didnt get cracked when they were installing your headers. Or make sure you dont have a bad plug wire.

My 2 cents <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

Just run the stock MAF Descreened (No Ported ends) I picked up 35RWHP in midrange and 30RWHP up top just by putting back in my stock MAF ends and making one AF change.
It is that big of a difference.
Chris

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Colonel:
<strong>The PCM will get the CLOSED LOOP operation back to stoic so long as the O2 sensors are working correctly and that the adjustments necessary to do so are within it's capabilities (which are pretty wide.)

The WOT (open loop) mixture will be affected by these closed loop changes but that doesn't mean that the mixture will be completely corrected as it should be. That's why porting the MAF will cause a PERMENENT leaning of the WOT mixture. The closed loop is richened back to stoic but the WOT is still left somewhat lean.

Most of the possible gains from porting a MAF are in the leaning of the mixture and the raising of the timing advance. Not from letting more air into the engine (it's not really much of a restriction once the screen is removed.)

Custom tuning does ALOT more than simply setting the WOT mixture. The timing advance under mulitple conditions can be manipulated, TQ management can be turned off, the rear O2 sensors can be turned off, knock sensors can be made less sensitive, the idle speed can be raised, etc, etc, etc, the list goes on and on.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">This is good stuff.

I had the liberty of speaking with a reputable tuner in the local area.

He showed me the way to alter A/F by manipulating Knock Retard Attack vs. RPM and Temp. Throttle voltage vs. angle %, tellin' the 'puter that the temp is this when it's actually that . . . a lotta this information might be mind-boggling or overwhelming for some, but I was FASCINATED <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

I wanna learn as much as possible <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

I'm gonna throw the stock de-screened ends back on until I get to the dyno/wideband O2.

Thanks for all the help guys <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Any other info is more than welcome <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />