Help with ATAP readings please.
Thread Starter
Staging Lane
Joined: Feb 2002
Posts: 83
Likes: 0
From: Knoxville TN
Help with ATAP readings please. I have a 98 ls1 with a few bolt-ons along with a hot cam.
THe car instantly started burning oil after the install. Everything has been done and redone to verify that nothing went astray during the install.
My second problem is that my car was running 8.40 @ 86.5 mph in the 1/8 mile with just a lid and catback.... now the car runs 8.40@ 86.5 mph with the addition of the hotcam and mac headers <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
I am lost and need your help in these two areas, i now have ATAP data thanks to Eric <wizkid>!
if some of ya'll would be willing to give it a look over, i could use any help i can get. One interesting note is the fact that on all the four full runs made, i had NO KR in first gear, but as soon as i wouold nail 2nd, it would instantly shoot up to 3 and gradually fall off <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
please take a look and post up opinions!
http://www.smfbodies.com/atap.htm
THe car instantly started burning oil after the install. Everything has been done and redone to verify that nothing went astray during the install.
My second problem is that my car was running 8.40 @ 86.5 mph in the 1/8 mile with just a lid and catback.... now the car runs 8.40@ 86.5 mph with the addition of the hotcam and mac headers <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
I am lost and need your help in these two areas, i now have ATAP data thanks to Eric <wizkid>!
if some of ya'll would be willing to give it a look over, i could use any help i can get. One interesting note is the fact that on all the four full runs made, i had NO KR in first gear, but as soon as i wouold nail 2nd, it would instantly shoot up to 3 and gradually fall off <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
please take a look and post up opinions!
http://www.smfbodies.com/atap.htm
Re: Help with ATAP readings please. First, I noticed was air intake temp in the 90s. How hot was it when you did your before & after track times?
LTRIMs indicate that you are probably lean overall, but the O2s were pretty good; maybe a hair rich.
LTRIMs indicate that you are probably lean overall, but the O2s were pretty good; maybe a hair rich.
Re: Help with ATAP readings please. Let me add some information here:
The car smokes like a freight train under acceleration. I have never seen an LS1 smoke this bad. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> It backfired a few times in between shifts too.
He has replaced the valve seals and re-checked the cam install. He has a GM Hotcam with LS6 springs. The PCV system has been plugged off and vented to the atmosphere so it can't pull oil back into the intake. (I believe he needs to get some vaccum back on there somehow).
I believe the weather was almost exactly the same on both track days.
This car does not feel like a cam'd car by any means.
I am thinking this might need to be in the internal section more so than in here too. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
So, any thoughts on why it is smoking so much oil immediately after the cam install?
Eric
The car smokes like a freight train under acceleration. I have never seen an LS1 smoke this bad. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> It backfired a few times in between shifts too.
He has replaced the valve seals and re-checked the cam install. He has a GM Hotcam with LS6 springs. The PCV system has been plugged off and vented to the atmosphere so it can't pull oil back into the intake. (I believe he needs to get some vaccum back on there somehow).
I believe the weather was almost exactly the same on both track days.
This car does not feel like a cam'd car by any means.
I am thinking this might need to be in the internal section more so than in here too. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
So, any thoughts on why it is smoking so much oil immediately after the cam install?
Eric
TECH Resident
Joined: Jan 2002
Posts: 754
Likes: 0
From: USA
Re: Help with ATAP readings please. Way too lean.
Non WOT LTFTs at +23% lean, going to WOT and STFT which handle up to 10% is frozen so that leaves 13% lean LTFT during WOT. LTFTs not zero'd out during WOT shows part throttle AFR way out of line.
WOT timing as low as 21 degrees to about 24 degrees, so lots of performance not being allowed to be used.
Inj pulse width shows tipping the 80% duty cycle max and during a longer WOT run would go even higher,
IAT values show air intake is not allowing good outside cool airflow and thus even by end of test run IAT still not down to what outside temps were (83 degrees)
Part throttle conditions DO effect the calibration going into a WOT state and during the WOT state esp when WOT is short term.
Non WOT LTFTs at +23% lean, going to WOT and STFT which handle up to 10% is frozen so that leaves 13% lean LTFT during WOT. LTFTs not zero'd out during WOT shows part throttle AFR way out of line.
WOT timing as low as 21 degrees to about 24 degrees, so lots of performance not being allowed to be used.
Inj pulse width shows tipping the 80% duty cycle max and during a longer WOT run would go even higher,
IAT values show air intake is not allowing good outside cool airflow and thus even by end of test run IAT still not down to what outside temps were (83 degrees)
Part throttle conditions DO effect the calibration going into a WOT state and during the WOT state esp when WOT is short term.
Re: Help with ATAP readings please. If the car is smoking like a freight train under 3/4 acceleration, that indicates it is rich, yet the computer is seeing a lean condition based upon the LTRIMs. I'd try new O2 sensors or try borrowing somebody's O2 sensors as a test.
Re: Help with ATAP readings please. I would say it definitely smokes under 3/4 acceleration.
Brian, try using your rear o2's you removed during your off road y-pipe install in place of your front ones and see what happens.
ERic
Brian, try using your rear o2's you removed during your off road y-pipe install in place of your front ones and see what happens.
ERic
Re: Help with ATAP readings please. 1) List all the mods to the car
2) If you have ported stock MAF, that could be causing the lean readings.
3) What color is the smoke?
4) Normal operating conditions would be 25-28 degrees of timing at WOT, and 02's in the low 900's.
5) Are the 02's bad? Are they not switching like normal? Try swapping in other ones or burn off the crap on the current ones.
6) Possibly have fouled plugs?
7) I'd try to get the 02's within +/-10%. Use a MAF T or play with MAF's or put in bigger injectors. 25% is MAX correction that the pcm can do FYI.
2) If you have ported stock MAF, that could be causing the lean readings.
3) What color is the smoke?
4) Normal operating conditions would be 25-28 degrees of timing at WOT, and 02's in the low 900's.
5) Are the 02's bad? Are they not switching like normal? Try swapping in other ones or burn off the crap on the current ones.
6) Possibly have fouled plugs?
7) I'd try to get the 02's within +/-10%. Use a MAF T or play with MAF's or put in bigger injectors. 25% is MAX correction that the pcm can do FYI.
Trending Topics
Re: Help with ATAP readings please. The smoke is dark and I believe it is oil. There is a TON of smoke coming out.
Modifications that were in working order:
LS1 Hotcam with LS6 springs
Mac headers with custom dual exhaust (2 bullet mufflers)
SLP air lid
160 t-stat
Tbyrne ported mass air flow ends
Cooling fan control
Removed A.I.R. pump
Removed EGR
Free Ram Air
Eric
Modifications that were in working order:
LS1 Hotcam with LS6 springs
Mac headers with custom dual exhaust (2 bullet mufflers)
SLP air lid
160 t-stat
Tbyrne ported mass air flow ends
Cooling fan control
Removed A.I.R. pump
Removed EGR
Free Ram Air
Eric
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Re: Help with ATAP readings please. One other thing, on the link posted above in the original post he has a link to the Auto Tap log and mod's on the car.
But his Fuel Trim Cell switches back and forth from 15 to 22 at WOT. Why is this?
Eric
But his Fuel Trim Cell switches back and forth from 15 to 22 at WOT. Why is this?
Eric
Thread Starter
Staging Lane
Joined: Feb 2002
Posts: 83
Likes: 0
From: Knoxville TN
Re: Help with ATAP readings please. Thanks everyone for their input....finally starting to get somewhere <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
I will put the stock descreened MAF ends on, i have a MAFT translator that i can richen up the base if needed.
Just curious, how much and the L Trims affect overall WOT performance....i still don't really understand that one.
What about the KR? is that alot? something to be concerned about...maybe b/c of the L Trims being Wacked? Never shows up in first gear tho...weird.
O2 sensors will be a little bit tricky, unless i can find a way to clean them....i know that they have been switching pretty good, has not show any indication that they are malfunctioning.Currently dont have the funds to replace them, and i can't remember what i did with the ones out of my OFF ROAD PIPE <img border="0" alt="[whiner]" title="" src="graemlins/gr_cry.gif" />
THe car has fresh plugs with about 1500 miles on them.
As for the smoke, i believe it is almost all oil, i am going to try and find a way to use the PCV system for now... i have read about using an air compressor filter that will filter out liquids, that sounds like the ticket!
SHould i consider going ahead and richening up the base, if so how much...this would be with the stock ends.
Once again...thanks for all the responses....please keep them coming, I will update as Eric and I work thru this
Props to you Eric, for all your help! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
I will put the stock descreened MAF ends on, i have a MAFT translator that i can richen up the base if needed.
Just curious, how much and the L Trims affect overall WOT performance....i still don't really understand that one.
What about the KR? is that alot? something to be concerned about...maybe b/c of the L Trims being Wacked? Never shows up in first gear tho...weird.
O2 sensors will be a little bit tricky, unless i can find a way to clean them....i know that they have been switching pretty good, has not show any indication that they are malfunctioning.Currently dont have the funds to replace them, and i can't remember what i did with the ones out of my OFF ROAD PIPE <img border="0" alt="[whiner]" title="" src="graemlins/gr_cry.gif" />
THe car has fresh plugs with about 1500 miles on them.
As for the smoke, i believe it is almost all oil, i am going to try and find a way to use the PCV system for now... i have read about using an air compressor filter that will filter out liquids, that sounds like the ticket!
SHould i consider going ahead and richening up the base, if so how much...this would be with the stock ends.
Once again...thanks for all the responses....please keep them coming, I will update as Eric and I work thru this
Props to you Eric, for all your help! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
Re: Help with ATAP readings please. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by wizkid:
<strong>
But his Fuel Trim Cell switches back and forth from 15 to 22 at WOT. Why is this?
Eric</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">His ported MAF ends are probably contributing to this problem. It probably will go away once he richens up the base with a MAFT or fixes the MAF rate in Edit.
<strong>
But his Fuel Trim Cell switches back and forth from 15 to 22 at WOT. Why is this?
Eric</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">His ported MAF ends are probably contributing to this problem. It probably will go away once he richens up the base with a MAFT or fixes the MAF rate in Edit.
Thread Starter
Staging Lane
Joined: Feb 2002
Posts: 83
Likes: 0
From: Knoxville TN
Re: Help with ATAP readings please. Ok, here is the second round of Atapping for the car.
www.smfbodies.com/atap2.html
the changes are as follows, the stock MAF was put into place and the pcv system was hooked back up with an air compressor filter in line with it to trap any oil
KR is still a little bit strange....seems like it could be associated with the tranny mount then the next pass would prove that wrong <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
but i feel like we are making progress,
the o2's at WOT are showing alittle bit lean, should i be concerned?
<small>[ June 23, 2002, 01:31 PM: Message edited by: SlowLS1 ]</small>
www.smfbodies.com/atap2.html
the changes are as follows, the stock MAF was put into place and the pcv system was hooked back up with an air compressor filter in line with it to trap any oil
KR is still a little bit strange....seems like it could be associated with the tranny mount then the next pass would prove that wrong <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
but i feel like we are making progress,
the o2's at WOT are showing alittle bit lean, should i be concerned?
<small>[ June 23, 2002, 01:31 PM: Message edited by: SlowLS1 ]</small>