From owner-xj-digest-at-digest.net Fri Feb 5 14:03:19 2010 From: xj-digest xj-digest Friday, February 5 2010 Volume 01 : Number 3154 Forum for Discussion of XJ cherokees and wagoneers Brian Colucci Digest Coordinator Contents: xj: smog challenge; high NO and CO; likely causes? Re: xj: smog challenge; high NO and CO; likely causes? Re: xj: smog challenge; high NO and CO; likely causes? Re: xj: smog challenge; high NO and CO; likely causes? Re: xj: smog challenge; high NO and CO; likely causes? XJ Digest Home Page: http://www.digest.net/jeep/xj/ Send submissions to xj-digest-at-digest.net Send administrative requests to xj-digest-request-at-digest.net To unsubscribe, include the word unsubscribe by itself in the body of the message, unless you are sending the request from a different address than the one that appears on the list. Include the word help in a message to xj-digest-request to get a list of other majordomo commands. ---------------------------------------------------------------------- Date: Fri, 05 Feb 2010 10:01:47 -0800 From: ernest breakfield Subject: xj: smog challenge; high NO and CO; likely causes? hi all! (apologies in advance for the wide distribution!) new challenge; our '94 XJ (4.0, 235K miles) just failed smog for the first time ever; both NO and CO readings were out of acceptable range -at- 15MPH, while only NO was high -at- 25MPH on the roller test (though it was *very* close* to the limit). HC readings were well within the allowable amounts at both speeds. 15MPH 25MPH %CO2 14.4 14.5 %O2 0.0 0.0 HC 48 (89 max) 38 (54 max) CO 1.08 (0.66 max) 1.04 (0.80 max) NO 633 (517 max) 767 (770 max) reading around, i haven't found a simple clear answer as to what the causes of this might be, and some of the shops i've talked to seem to be taking a "guess and shotgun" approach as to how to deal with it. for reference; oil had been changed ~50 miles earlier; has been Red Line synthetic for most of the last 200K miles. vehicle had been driven at mostly highway speeds for almost an hour immediately before the test, and didn't sit for more than a few minutes before it went on the rollers... but it was a rainy day and everything was quite wet. have since changed the Air Filter and done a Seafoam treatment just on the chance that it might help clear out some gunk build-up in the combustion chamber (2/3 down the throttle body and 1/3 in the fuel); the smoke cloud created would have been the envy of James Bond, and it actually seems to have evened out the idle a bit. did some preliminary banging around on the exhaust system, but don't seem to have any undue rattles indicating any obviously broken internal bits. TPS, O2 sensor have been there for probably ~100K+ miles, as has the set of injectors that's in there now. have a fresh fuel filter that i plan to put in (as part of a general overdue tune-up). have a fresh set of plugs that i plan to put in when i take out the ones that are in there to 'read' them to see if there's any clues there. can anyone point me to a clear simple listing of what the causes are likely to be for each of these parameters being over these limits? i'm not fond of guesses when the guys who are making the guesses are making money off of it whether they're solving the problem or not, and would prefer to educate myself further on the topic before going to talk with the Smog repair folk. we do have a program here in California to provide financial assistance for repair of smog-failure related items (State pays up to $500 after you pay the first $100), and although this vehicle qualifies, i don't want to have to get into that if it's something simple and/or that i should be able to take care of myself. there's (yet another) new law now regarding the certification of Catalytic Converters, and they've suddenly become even more expensive; if that's going to be part of what needs to be replaced, i want to make sure that the Government money gets spent on that and i do what i can myself in a more cost-effective manner beforehand. any hints; tips clues appreciated! cheers! e ------------------------------ Date: Fri, 5 Feb 2010 10:36:16 -0800 From: Kevin Subject: Re: xj: smog challenge; high NO and CO; likely causes? Do you have an exhaust leak from a cracked manifold, or did you for a longish period of time? That failing, what type of driving does the car normally see (knowing you live in the bay area "highway" can mean more stop and go than anything), how far advanced is the timing, have you noticed a difference in mileage lately, what type of O2 sensor did you put in, and what type of fuel do you run in it? Has it pinged recently? On Fri, Feb 05, 2010 at 10:01:47AM -0800, ernest breakfield wrote: > hi all! > > (apologies in advance for the wide distribution!) > > new challenge; our '94 XJ (4.0, 235K miles) just failed smog for the > first time ever; both NO and CO readings were out of acceptable range -at- > 15MPH, while only NO was high -at- 25MPH on the roller test (though it was > *very* close* to the limit). HC readings were well within the allowable > amounts at both speeds. > > 15MPH 25MPH > %CO2 14.4 14.5 > %O2 0.0 0.0 > HC 48 (89 max) 38 (54 max) > CO 1.08 (0.66 max) 1.04 (0.80 max) > NO 633 (517 max) 767 (770 max) > > > reading around, i haven't found a simple clear answer as to what the > causes of this might be, and some of the shops i've talked to seem to be > taking a "guess and shotgun" approach as to how to deal with it. > > for reference; oil had been changed ~50 miles earlier; has been Red > Line synthetic for most of the last 200K miles. > vehicle had been driven at mostly highway speeds for almost an hour > immediately before the test, and didn't sit for more than a few minutes > before it went on the rollers... but it was a rainy day and everything > was quite wet. > have since changed the Air Filter and done a Seafoam treatment just > on the chance that it might help clear out some gunk build-up in the > combustion chamber (2/3 down the throttle body and 1/3 in the fuel); the > smoke cloud created would have been the envy of James Bond, and it > actually seems to have evened out the idle a bit. > did some preliminary banging around on the exhaust system, but don't > seem to have any undue rattles indicating any obviously broken internal > bits. > TPS, O2 sensor have been there for probably ~100K+ miles, as has the > set of injectors that's in there now. > have a fresh fuel filter that i plan to put in (as part of a general > overdue tune-up). > have a fresh set of plugs that i plan to put in when i take out the > ones that are in there to 'read' them to see if there's any clues there. > > can anyone point me to a clear simple listing of what the causes are > likely to be for each of these parameters being over these limits? i'm > not fond of guesses when the guys who are making the guesses are making > money off of it whether they're solving the problem or not, and would > prefer to educate myself further on the topic before going to talk with > the Smog repair folk. > > we do have a program here in California to provide financial > assistance for repair of smog-failure related items (State pays up to > $500 after you pay the first $100), and although this vehicle qualifies, > i don't want to have to get into that if it's something simple and/or > that i should be able to take care of myself. there's (yet another) new > law now regarding the certification of Catalytic Converters, and they've > suddenly become even more expensive; if that's going to be part of what > needs to be replaced, i want to make sure that the Government money gets > spent on that and i do what i can myself in a more cost-effective manner > beforehand. > > any hints; tips clues appreciated! > > > cheers! > e ------------------------------ Date: Fri, 05 Feb 2010 11:30:26 -0800 From: ernest breakfield Subject: Re: xj: smog challenge; high NO and CO; likely causes? hi Kevin! no mani cracks since i put the Borla exhaust in ~10 years ago; wasn't cracked for long then, either. vehicle sees a mixture of around-town and highway (defined as 'at speed') driving. little-to-no stop and go; i use the moto for those conditions. FWIW, we make a point of making sure all the vehicles get some extended hwy time at least once a month or so. timing is wherever the computer sets it; not adjustable, and there's no codes to indicate anything out of sorts there. no changes in MPG noticed; pretty much has been getting the same MPG for years. O2 sensor? don't recall what kind; whatever the dealer was selling at the time, i guess... it's been there for some number of years already. (i changed it out as PM then because it was original, but it didn't make any noticeable difference whatsoever. has passed smog several times since then.) always run regular (almost always Chevron), and have no indication of pinging. cheers! e Kevin wrote: > Do you have an exhaust leak from a cracked manifold, or did you for a > longish period of time? > > That failing, what type of driving does the car normally see (knowing you > live in the bay area "highway" can mean more stop and go than anything), how > far advanced is the timing, have you noticed a difference in mileage lately, > what type of O2 sensor did you put in, and what type of fuel do you run in it? > Has it pinged recently? > > On Fri, Feb 05, 2010 at 10:01:47AM -0800, ernest breakfield wrote: > >> hi all! >> >> (apologies in advance for the wide distribution!) >> >> new challenge; our '94 XJ (4.0, 235K miles) just failed smog for the >> first time ever; both NO and CO readings were out of acceptable range -at- >> 15MPH, while only NO was high -at- 25MPH on the roller test (though it was >> *very* close* to the limit). HC readings were well within the allowable >> amounts at both speeds. >> >> 15MPH 25MPH >> %CO2 14.4 14.5 >> %O2 0.0 0.0 >> HC 48 (89 max) 38 (54 max) >> CO 1.08 (0.66 max) 1.04 (0.80 max) >> NO 633 (517 max) 767 (770 max) >> >> >> reading around, i haven't found a simple clear answer as to what the >> causes of this might be, and some of the shops i've talked to seem to be >> taking a "guess and shotgun" approach as to how to deal with it. >> >> for reference; oil had been changed ~50 miles earlier; has been Red >> Line synthetic for most of the last 200K miles. >> vehicle had been driven at mostly highway speeds for almost an hour >> immediately before the test, and didn't sit for more than a few minutes >> before it went on the rollers... but it was a rainy day and everything >> was quite wet. >> have since changed the Air Filter and done a Seafoam treatment just >> on the chance that it might help clear out some gunk build-up in the >> combustion chamber (2/3 down the throttle body and 1/3 in the fuel); the >> smoke cloud created would have been the envy of James Bond, and it >> actually seems to have evened out the idle a bit. >> did some preliminary banging around on the exhaust system, but don't >> seem to have any undue rattles indicating any obviously broken internal >> bits. >> TPS, O2 sensor have been there for probably ~100K+ miles, as has the >> set of injectors that's in there now. >> have a fresh fuel filter that i plan to put in (as part of a general >> overdue tune-up). >> have a fresh set of plugs that i plan to put in when i take out the >> ones that are in there to 'read' them to see if there's any clues there. >> >> can anyone point me to a clear simple listing of what the causes are >> likely to be for each of these parameters being over these limits? i'm >> not fond of guesses when the guys who are making the guesses are making >> money off of it whether they're solving the problem or not, and would >> prefer to educate myself further on the topic before going to talk with >> the Smog repair folk. >> >> we do have a program here in California to provide financial >> assistance for repair of smog-failure related items (State pays up to >> $500 after you pay the first $100), and although this vehicle qualifies, >> i don't want to have to get into that if it's something simple and/or >> that i should be able to take care of myself. there's (yet another) new >> law now regarding the certification of Catalytic Converters, and they've >> suddenly become even more expensive; if that's going to be part of what >> needs to be replaced, i want to make sure that the Government money gets >> spent on that and i do what i can myself in a more cost-effective manner >> beforehand. >> >> any hints; tips clues appreciated! >> >> >> cheers! >> e ------------------------------ Date: Fri, 5 Feb 2010 13:31:51 -0800 (PST) From: john Subject: Re: xj: smog challenge; high NO and CO; likely causes? is your EGR working properly? higher temperatures or running lean would run the Oxides of Nitrogen up... and HC down... not sure of the relationship of CO... but it might follow... are all your injectors working properly? what do your plugs look like? are they all light tan? any white? john ----- - ------------------------------------------------------------------------ Snohomish, Washington -o|||||o- where Jeeps don't rust, they mold http://AMSOIL.com/redirect.cgi?zo=283461 si vis pacem, para bellum http://johnmeister.com http://wagoneers.com http://fotomeister.us - ------------------------------------------------------------------------ On Fri, 5 Feb 2010, ernest breakfield wrote: # hi all! # # (apologies in advance for the wide distribution!) # # new challenge; our '94 XJ (4.0, 235K miles) just failed smog for the # first time ever; both NO and CO readings were out of acceptable range -at- # 15MPH, while only NO was high -at- 25MPH on the roller test (though it was # *very* close* to the limit). HC readings were well within the allowable # amounts at both speeds. # # 15MPH 25MPH # %CO2 14.4 14.5 # %O2 0.0 0.0 # HC 48 (89 max) 38 (54 max) # CO 1.08 (0.66 max) 1.04 (0.80 max) # NO 633 (517 max) 767 (770 max) # # # reading around, i haven't found a simple clear answer as to what the # causes of this might be, and some of the shops i've talked to seem to be # taking a "guess and shotgun" approach as to how to deal with it. # # for reference; oil had been changed ~50 miles earlier; has been Red # Line synthetic for most of the last 200K miles. # vehicle had been driven at mostly highway speeds for almost an hour # immediately before the test, and didn't sit for more than a few minutes # before it went on the rollers... but it was a rainy day and everything # was quite wet. # have since changed the Air Filter and done a Seafoam treatment just # on the chance that it might help clear out some gunk build-up in the # combustion chamber (2/3 down the throttle body and 1/3 in the fuel); the # smoke cloud created would have been the envy of James Bond, and it # actually seems to have evened out the idle a bit. # did some preliminary banging around on the exhaust system, but don't # seem to have any undue rattles indicating any obviously broken internal # bits. # TPS, O2 sensor have been there for probably ~100K+ miles, as has the # set of injectors that's in there now. # have a fresh fuel filter that i plan to put in (as part of a general # overdue tune-up). # have a fresh set of plugs that i plan to put in when i take out the # ones that are in there to 'read' them to see if there's any clues there. # # can anyone point me to a clear simple listing of what the causes are # likely to be for each of these parameters being over these limits? i'm # not fond of guesses when the guys who are making the guesses are making # money off of it whether they're solving the problem or not, and would # prefer to educate myself further on the topic before going to talk with # the Smog repair folk. # # we do have a program here in California to provide financial # assistance for repair of smog-failure related items (State pays up to # $500 after you pay the first $100), and although this vehicle qualifies, # i don't want to have to get into that if it's something simple and/or # that i should be able to take care of myself. there's (yet another) new # law now regarding the certification of Catalytic Converters, and they've # suddenly become even more expensive; if that's going to be part of what # needs to be replaced, i want to make sure that the Government money gets # spent on that and i do what i can myself in a more cost-effective manner # beforehand. # # any hints; tips clues appreciated! # # # cheers! # e # ------------------------------ Date: Fri, 05 Feb 2010 14:03:32 -0800 From: ernest breakfield Subject: Re: xj: smog challenge; high NO and CO; likely causes? EGR is working as well as it's ever going to; there isn't one on a '94 4.0 XJ. ;-) changed the fuel filter too; blowing through them, it seems like the old one is considerably more restrictive than the new one, but i'm not sure if that's a valid comparison since the old one was wet, but the new one was dry,... either way, putting a new one in can't hurt. thinking Gump, i figure if fuel mixture is in question, let's make sure that fuel can easily get to where it needs to go. (is my diesel experience showing? ;-) ) just finished changing the plugs, and they all look pretty consistent and much like they all always have; a little on the light side of tan leaning towards white-ish, but that's how they've always looked. most interestingly, all of them gapped out well over spec; they'd worn to just over and under ~.045" (spec is .035). i used Autolites last time around (and it doesn't seem like it was that many miles ago), but having seen this, went back to Champions this time. test starts seemed a bit smoother at idle (as might be expected), but didn't get a chance to drive it yet; pulled off the dist cap to look at the cap and rotor contacts and found that the rotor contact had separated from the rotor body,... think that might be a problem? ;-0 cheers! e john wrote: > is your EGR working properly? > > higher temperatures or running lean would run the Oxides of Nitrogen > up... and HC down... not sure of the relationship of CO... but it might > follow... > > are all your injectors working properly? > > what do your plugs look like? are they all light tan? any white? > > john > > > > > ----- > ------------------------------------------------------------------------ > Snohomish, Washington -o|||||o- where Jeeps don't rust, they mold > http://AMSOIL.com/redirect.cgi?zo=283461 si vis pacem, para bellum > http://johnmeister.com http://wagoneers.com http://fotomeister.us > ------------------------------------------------------------------------ > > > On Fri, 5 Feb 2010, ernest breakfield wrote: > > # hi all! > # > # (apologies in advance for the wide distribution!) > # > # new challenge; our '94 XJ (4.0, 235K miles) just failed smog for the > # first time ever; both NO and CO readings were out of acceptable range -at- > # 15MPH, while only NO was high -at- 25MPH on the roller test (though it was > # *very* close* to the limit). HC readings were well within the allowable > # amounts at both speeds. > # > # 15MPH 25MPH > # %CO2 14.4 14.5 > # %O2 0.0 0.0 > # HC 48 (89 max) 38 (54 max) > # CO 1.08 (0.66 max) 1.04 (0.80 max) > # NO 633 (517 max) 767 (770 max) > # > # > # reading around, i haven't found a simple clear answer as to what the > # causes of this might be, and some of the shops i've talked to seem to be > # taking a "guess and shotgun" approach as to how to deal with it. > # > # for reference; oil had been changed ~50 miles earlier; has been Red > # Line synthetic for most of the last 200K miles. > # vehicle had been driven at mostly highway speeds for almost an hour > # immediately before the test, and didn't sit for more than a few minutes > # before it went on the rollers... but it was a rainy day and everything > # was quite wet. > # have since changed the Air Filter and done a Seafoam treatment just > # on the chance that it might help clear out some gunk build-up in the > # combustion chamber (2/3 down the throttle body and 1/3 in the fuel); the > # smoke cloud created would have been the envy of James Bond, and it > # actually seems to have evened out the idle a bit. > # did some preliminary banging around on the exhaust system, but don't > # seem to have any undue rattles indicating any obviously broken internal > # bits. > # TPS, O2 sensor have been there for probably ~100K+ miles, as has the > # set of injectors that's in there now. > # have a fresh fuel filter that i plan to put in (as part of a general > # overdue tune-up). > # have a fresh set of plugs that i plan to put in when i take out the > # ones that are in there to 'read' them to see if there's any clues there. > # > # can anyone point me to a clear simple listing of what the causes are > # likely to be for each of these parameters being over these limits? i'm > # not fond of guesses when the guys who are making the guesses are making > # money off of it whether they're solving the problem or not, and would > # prefer to educate myself further on the topic before going to talk with > # the Smog repair folk. > # > # we do have a program here in California to provide financial > # assistance for repair of smog-failure related items (State pays up to > # $500 after you pay the first $100), and although this vehicle qualifies, > # i don't want to have to get into that if it's something simple and/or > # that i should be able to take care of myself. there's (yet another) new > # law now regarding the certification of Catalytic Converters, and they've > # suddenly become even more expensive; if that's going to be part of what > # needs to be replaced, i want to make sure that the Government money gets > # spent on that and i do what i can myself in a more cost-effective manner > # beforehand. > # > # any hints; tips clues appreciated! > # > # > # cheers! > # e > # ------------------------------ End of xj-digest V1 #3154 *************************