silvermistLS Posted November 21, 2008 Share Posted November 21, 2008 Hi all, Just had a quick question on something that I've noticed over the past month or so.. I have a 93 LS with 125K miles on it. It had a major maint. done at 120K including new denso iridium plugs, full trany flush, oil, cooland flush, and runs like a champ. I have however, notice a weird roughness when I jump in the car in the morning or after it's been sitting for a day or many hours... the revs go up to like 1000 or 1200 which is normal, but then there is just a slight vibration. But once it warms up, there is not such vibration anymore. Even after it sits another 3 or 4 hours, there is no vibration when I start the car, just when it's cold (engine) i guess. Anyone have any ideas as to what this could be, or is it something to worry about? like I said, beyond it being annoying, the cars runs normal. Thanks, Quote Link to comment Share on other sites More sharing options...
silvermistLS Posted November 22, 2008 Author Share Posted November 22, 2008 After speaking to my mechanic today, he told me it could be condensation or water getting into 1 or more of the cilinders.. or through a bad gasket. He said that this would explain why it idles rough when it warms up and then decipates once the car is warm ( this morning, I decided to pay more attention to it, and accelerate it myself after about 2 minutes of warming up... and yes the roughness is still present at approx. 1200rpm... and some other parts of the rev range just don't seem as smooth as they where 2 or 3 months ago. After about 15 minutes, then it's back to normal... so it takes a while to get that ??water?? out maybe.. The mechanic said "wait till the engine light comes on, that way we'll know if will probably be a misfire from one of the cylinders once we hook it up to the computer.. Anyone every experienced something like this?? I've always been on top of the maintenance (car was dealer maintained) and can't think it could be the motor.. could it be a motor mount? I put it in neutral, and it does the same thing when cold.... HELP!!! Thanks, guys. Quote Link to comment Share on other sites More sharing options...
silvermistLS Posted November 22, 2008 Author Share Posted November 22, 2008 anyone...? Quote Link to comment Share on other sites More sharing options...
silvermistLS Posted November 26, 2008 Author Share Posted November 26, 2008 Okay, I guess no one has experienced the problem I have.. In case it comes up for someone, I've learned from several mechs.. that I could be the spark plug wires, and cap and rotors... (as opposed to some condensation or water leaking into 1 or more cylinders). I'll post if I learn what it could be. Quote Link to comment Share on other sites More sharing options...
eatingupblacktop Posted November 26, 2008 Share Posted November 26, 2008 You might be getting codes without the cel coming on. http://www.lexls.com/tutorials/intro/codereading.html Quote Link to comment Share on other sites More sharing options...
stylz Posted November 26, 2008 Share Posted November 26, 2008 i havent had it happen on my LS but not to long ago it happened on a ford of mine. ...its sounds like its a bad gasket, water sips through. when the water evaporates from the heat of the motor it runs fine. its only gonna get worst if its the gasket. if you have good mechs...they should know if its a gasket....let us know. Quote Link to comment Share on other sites More sharing options...
silvermistLS Posted November 27, 2008 Author Share Posted November 27, 2008 I hope it's not the gasket, the car has always been dealer maint., and they say the gaskets on these cars never go.... I will take it to a lex mechanic next week.. he said he wants to check the wires... I think they are the originals.. and it does have 125k miles.... Quote Link to comment Share on other sites More sharing options...
killerFatty Posted November 27, 2008 Share Posted November 27, 2008 My 93 was vibrating and sputtering but all was fixed after the plugs and wires were replaced. Hope that helps. :) Quote Link to comment Share on other sites More sharing options...
silvermistLS Posted November 30, 2008 Author Share Posted November 30, 2008 THanks KillerFatty.. I replaced plugs about 4 months ago, but did not do wires or cap and rotor.. Wires are originals I think.. I hope that does the trick... 1st I will run OBD1 to see if any code is coming up... although nothing lights up on dash. Quote Link to comment Share on other sites More sharing options...
lextuned Posted December 1, 2008 Share Posted December 1, 2008 THanks KillerFatty.. I replaced plugs about 4 months ago, but did not do wires or cap and rotor.. Wires are originals I think.. I hope that does the trick... 1st I will run OBD1 to see if any code is coming up... although nothing lights up on dash. Totall yodd, i never heard of any gaskets going out on a v8 lexus, especially an engine gasket. Take it to someone who knows what there doing- chutch Quote Link to comment Share on other sites More sharing options...
python Posted December 1, 2008 Share Posted December 1, 2008 its not the wires or plugs or anything like that otherwise it would do it all the time.....things like tps,maf,iac are things that control air/fuel mixture and idling....maybe ur throttle body needs cleaning....just throwing out suggestions here Quote Link to comment Share on other sites More sharing options...
eatingupblacktop Posted December 2, 2008 Share Posted December 2, 2008 One thing you can try that won't cost you anything is checking the EFI relay and making sure it's securely connected when you put it back in. Sticking injector until it warms up is another possibility. An igniter that's starting to fail might be another. Take your car to the garage you trust and leave it overnight. Have them scope it next morning when it's cold. Simple test, shouldn't cost much. Quote Link to comment Share on other sites More sharing options...
silvermistLS Posted December 3, 2008 Author Share Posted December 3, 2008 its not the wires or plugs or anything like that otherwise it would do it all the time.....things like tps,maf,iac are things that control air/fuel mixture and idling....maybe ur throttle body needs cleaning....just throwing out suggestions here Python, you are the man!! this other mechanic friend of mine hooked the car up to the computer to see if it was throwing some kinda code.... Sure enough... TPS sensor. He got it from this warehouse for 98 bucks (toyota original) and will be installing it tomorrow. Hopefully this is the issue. I will report tomorrow guys once I get it installed and see if that resolves the issue. Quote Link to comment Share on other sites More sharing options...
silvermistLS Posted December 3, 2008 Author Share Posted December 3, 2008 btw here are some pics of my 93 silvermist... awesome car.. drives like new. Quote Link to comment Share on other sites More sharing options...
silvermistLS Posted December 5, 2008 Author Share Posted December 5, 2008 Alrighty..So I had the TPS changed, and my mech also adjusted the throttle positioning (meaning rotated the TPS clockwise, since when he first installed the TPS and reset the fuse, the car was idling in park, at 1000RPM. When he hooked it up to computer, the error 41 (bad TPS) was gone.. after cycling through the program, it said throttle opening degree needed to be at 76-80 degrees, mine was at 73. He adjusted it to 78, and boy it made a significant difference.. as before, the throttle seemed hard or sluggish. The morning vibrations are still there, but not as prevalent. I'll just have to wait and see what that does.. but as far as throttle application and response, MUCH better! Thanks, Al Quote Link to comment Share on other sites More sharing options...
Bali26 Posted December 5, 2008 Share Posted December 5, 2008 Silver, please get a better mechanic. Your vibrations are due to bad motor mounts (felt at a particular rpm range). $90 each x2. Search for it. Please don't mess around with the cylinder heads. Keep us posted. Quote Link to comment Share on other sites More sharing options...
xoneinax Posted December 5, 2008 Share Posted December 5, 2008 My 93 was vibrating and sputtering but all was fixed after the plugs and wires were replaced.Me too. Before that was misfiring on 2 or 3 cylinders. Quote Link to comment Share on other sites More sharing options...
mnesbit Posted December 5, 2008 Share Posted December 5, 2008 I get the same roughness for a very short period of time on my 95 LS 400 which has 240,000 miles on it. The car runs very smooth with good power and I get over 525 miles on a tank of gas on the highway so I don't worry about it. The roughness is also accompanied by puffs of smoke so I think the cylinders are just cleaning themselves out. Quote Link to comment Share on other sites More sharing options...
don corleone Posted December 6, 2008 Share Posted December 6, 2008 Everyone with 95 Ls's should do a search for the 95/96 engine thread. happens to alot of ppl and couldn't hurt to check it out. Also a Mod should Make that a Sticky so future members can have easy access to it. Quote Link to comment Share on other sites More sharing options...
silvermistLS Posted December 7, 2008 Author Share Posted December 7, 2008 Well, In regards, to motormounts, they were checked and seem to be good. Tell me if I'm wrong, but here's the way to check them... Put car in park, apply hand brake, as well as regular foot brake, and then gently accelerate to maybe 2k rpm in order to notice if there is engine flex or movement. Well, there is none with mine. I think if it was an engine mount issue, it would always vibrate at that RPM, and the truth is that it only does it when the engine is cold... There is something wrong, like maybe an injector, or a sensor somewhere that is making it not idle or run right. As I mentioned before, the car is not eating up any oil, it's not smoking at all, I'm puzzled... I'm thinking of taking it to a lexus only mechanic that was recommended to me. One question, will the computer tell me if there is an issue with the sparkplug wires, or cap and rotors? After hooking it up and getting the 41 error code (TPS) and changing the TPS, it now reads clear. But I'm wondering if there might be issues with the wires... Certainly hope it's not an engine issue... I couldn't imagine it, since it's always had meticulous maintenance record. Quote Link to comment Share on other sites More sharing options...
python Posted December 7, 2008 Share Posted December 7, 2008 put some REDLINE FUEL SYSTEM CLEANER in it and watch it smooth right out....put in 1/3 a bottle with a 1/4 tank of gas to get it good and clean the first time http://www.redlineoil.com/products_fueladd...ubCategoryID=11 Quote Link to comment Share on other sites More sharing options...
210ls400 Posted December 12, 2008 Share Posted December 12, 2008 what is a "TPS sensor" and where is it located in a 92ls400. I have been having the same problem. thanks for the help. Quote Link to comment Share on other sites More sharing options...
killerFatty Posted December 15, 2008 Share Posted December 15, 2008 My 93 is vibrating and shuttering after cold starts. It takes a good 4 seconds of cranking to get her goin', and when it gets going there is a breif, strange, grinding skreeching noise. the car vibrates until warm, like Silver. I am going to pull the codes and clean the throttle body asap, but i was wondering how you are supposed to know where the TPS needs to be adjusted to. Thanks in advance. Quote Link to comment Share on other sites More sharing options...
eatingupblacktop Posted December 16, 2008 Share Posted December 16, 2008 what is a "TPS sensor" and where is it located in a 92ls400. I have been having the same problem. thanks for the help. My 93 is vibrating and shuttering after cold starts. It takes a good 4 seconds of cranking to get her goin', and when it gets going there is a breif, strange, grinding skreeching noise. the car vibrates until warm, like Silver. I am going to pull the codes and clean the throttle body asap, but i was wondering how you are supposed to know where the TPS needs to be adjusted to. Thanks in advance. You know the TPS will pop a code if there's a prob. If you're just doing maintenance, here's the htd: http://www.lexls.com/tutorials/EFI/tps.html Quote Link to comment Share on other sites More sharing options...
210ls400 Posted December 16, 2008 Share Posted December 16, 2008 what is a "TPS sensor" and where is it located in a 92ls400. I have been having the same problem. thanks for the help. My 93 is vibrating and shuttering after cold starts. It takes a good 4 seconds of cranking to get her goin', and when it gets going there is a breif, strange, grinding skreeching noise. the car vibrates until warm, like Silver. I am going to pull the codes and clean the throttle body asap, but i was wondering how you are supposed to know where the TPS needs to be adjusted to. Thanks in advance. You know the TPS will pop a code if there's a prob. If you're just doing maintenance, here's the htd: http://www.lexls.com/tutorials/EFI/tps.html thanks for all the help guys now i can check al this stuff. Is royal purple a good oil to use in such an old car with 218000 miles on it? Quote Link to comment Share on other sites More sharing options...
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