Engine idling high/low/high/low aka rpm hunting. Please advise.
10-22-14, 11:52 AM
#16
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Isn't 95 still OBDI? Idk but yes read that they're not so compatible just being 92-94. Guy said yes tho. Idk why he would want mine but glad he's doing the swap. Also if anybody needs there Ecu rebuilt hit up Darryl Geller (404) 550-7511 tell him Felipe sent yall. Has plenty of good feedback on here.
10-25-14, 12:52 PM
#18
I finally remembered the main source of what led me to believe '95 switched over to OBDII.
http://www.lexls.com/tutorials/intro/codereading.html
That's for the LS400, but most such stuff is similar across platforms. Maybe this is a counter-example.
http://www.lexls.com/tutorials/intro/codereading.html
That's for the LS400, but most such stuff is similar across platforms. Maybe this is a counter-example.
10-26-14, 10:18 AM
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I finally remembered the main source of what led me to believe '95 switched over to OBDII.
http://www.lexls.com/tutorials/intro/codereading.html
That's for the LS400, but most such stuff is similar across platforms. Maybe this is a counter-example.
http://www.lexls.com/tutorials/intro/codereading.html
That's for the LS400, but most such stuff is similar across platforms. Maybe this is a counter-example.
11-12-14, 07:59 AM
#20
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I had the ECU serviced. Per diagnostic, the capacitors were bad. All caps were changed to new.
Since the issue is so intermittent, I'm not 100% positive it is "fixed," but I would say it is resolved.
It revved once since the ECU change, but self-corrected in about 4 seconds--which it's never done before. No problem since that one incident.
FWIW,
1) I'm not a talented DIY auto guy. If I can do this, then almost anyone can. I had help removing it, but trust me, "you can do it!" And, you don't need to remove the glovebox to access the unit. Just "work" the carpet back and it's fairly obvious what to do after that.
2) Based on what I've read, sooner or later these caps will go bad. And, once they are not operating they cause a plethora of difficult to resolve issues. It's worthwhile to consider this moderately low cost repair before venturing into the more expensive parts and additional diagnostics.
That's my minor contribution to anyone reading this thread.
Thank you to all who've responded. Special thanks to Banks.
Now, I have to resolve a new issue. I may post this, too.
When accelerating, the car is fine. But, when the car slows down and my foot is off the gas, there is a “clunking” sound emanating from the right front. It’s there consistently.
I don’t know how to describe it, exactly, but kind of like one or two clunking noises as I decelerate. Seems like a very “physical” sound. I hope it’s something “minor” like bushings, ball joint or tie rods. It’s drivable, but I don't know what might just "give out" and leave me stranded. I’m supposed to drive 300 miles about 2 weeks from now and I must check this out.
Anyone with any ideas, please post or PM me.
Thanks.
Since the issue is so intermittent, I'm not 100% positive it is "fixed," but I would say it is resolved.
It revved once since the ECU change, but self-corrected in about 4 seconds--which it's never done before. No problem since that one incident.
FWIW,
1) I'm not a talented DIY auto guy. If I can do this, then almost anyone can. I had help removing it, but trust me, "you can do it!" And, you don't need to remove the glovebox to access the unit. Just "work" the carpet back and it's fairly obvious what to do after that.
2) Based on what I've read, sooner or later these caps will go bad. And, once they are not operating they cause a plethora of difficult to resolve issues. It's worthwhile to consider this moderately low cost repair before venturing into the more expensive parts and additional diagnostics.
That's my minor contribution to anyone reading this thread.
Thank you to all who've responded. Special thanks to Banks.
Now, I have to resolve a new issue. I may post this, too.
When accelerating, the car is fine. But, when the car slows down and my foot is off the gas, there is a “clunking” sound emanating from the right front. It’s there consistently.
I don’t know how to describe it, exactly, but kind of like one or two clunking noises as I decelerate. Seems like a very “physical” sound. I hope it’s something “minor” like bushings, ball joint or tie rods. It’s drivable, but I don't know what might just "give out" and leave me stranded. I’m supposed to drive 300 miles about 2 weeks from now and I must check this out.
Anyone with any ideas, please post or PM me.
Thanks.
11-12-14, 08:03 AM
#21
I had the ECU serviced. Per diagnostic, the capacitors were bad. All caps were changed to new.
Since the issue is so intermittent, I'm not 100% positive it is "fixed," but I would say it is resolved.
It revved once since the ECU change, but self-corrected in about 4 seconds--which it's never done before. No problem since that one incident.
FWIW,
1) I'm not a talented DIY auto guy. If I can do this, then almost anyone can. I had help removing it, but trust me, "you can do it!" And, you don't need to remove the glovebox to access the unit. Just "work" the carpet back and it's fairly obvious what to do after that.
2) Based on what I've read, sooner or later these caps will go bad. And, once they are not operating they cause a plethora of difficult to resolve issues. It's worthwhile to consider this moderately low cost repair before venturing into the more expensive parts and additional diagnostics.
That's my minor contribution to anyone reading this thread.
Thank you to all who've responded. Special thanks to Banks.
Now, I have to resolve a new issue. I may post this, too.
When accelerating, the car is fine. But, when the car slows down and my foot is off the gas, there is a “clunking” sound emanating from the right front. It’s there consistently.
I don’t know how to describe it, exactly, but kind of like one or two clunking noises as I decelerate. Seems like a very “physical” sound. I hope it’s something “minor” like bushings, ball joint or tie rods. It’s drivable, but I don't know what might just "give out" and leave me stranded. I’m supposed to drive 300 miles about 2 weeks from now and I must check this out.
Anyone with any ideas, please post or PM me.
Thanks.
Since the issue is so intermittent, I'm not 100% positive it is "fixed," but I would say it is resolved.
It revved once since the ECU change, but self-corrected in about 4 seconds--which it's never done before. No problem since that one incident.
FWIW,
1) I'm not a talented DIY auto guy. If I can do this, then almost anyone can. I had help removing it, but trust me, "you can do it!" And, you don't need to remove the glovebox to access the unit. Just "work" the carpet back and it's fairly obvious what to do after that.
2) Based on what I've read, sooner or later these caps will go bad. And, once they are not operating they cause a plethora of difficult to resolve issues. It's worthwhile to consider this moderately low cost repair before venturing into the more expensive parts and additional diagnostics.
That's my minor contribution to anyone reading this thread.
Thank you to all who've responded. Special thanks to Banks.
Now, I have to resolve a new issue. I may post this, too.
When accelerating, the car is fine. But, when the car slows down and my foot is off the gas, there is a “clunking” sound emanating from the right front. It’s there consistently.
I don’t know how to describe it, exactly, but kind of like one or two clunking noises as I decelerate. Seems like a very “physical” sound. I hope it’s something “minor” like bushings, ball joint or tie rods. It’s drivable, but I don't know what might just "give out" and leave me stranded. I’m supposed to drive 300 miles about 2 weeks from now and I must check this out.
Anyone with any ideas, please post or PM me.
Thanks.
Anyways, sounds like the issue I had on my first SC. It sounded like someone was hitting a stick undrneath the car by the console, literally. Even an aauto mechanic said it could be something mechanical, like the tranny mount. I replaced it and it didn't fix it. The car would buck and kick when slight throttle was used or it was coasting at 40. It ended up being bad o2 sensors. Mostly upstream o2 sensors. Also in your case, it wouldnt hurt to set your TPS to spec if you have a multimeter.
11-16-14, 12:11 PM
#22
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Here's an update. I thank all for feedback.
BTW, the car ran almost flawlessly for 3 years. Yes, there were repairs, but nothing that unusual.
And, "odd sounds" were readily attributable to obvious things like a bad steering pump.
Since repairing and re-installing the ECU, the following occurred:
A few times, consecutively on different days, the car would start, but then stall. Re-start = stall again. I’d finally have to start and lightly rev the engine for about a minute. Then, the car did not stall. Subsequent re-starts when the car was already warm = great. This happened about 5 times and has not re-occurred. In fact, surprisingly, it started without a hitch on a cold morning.
Reviing up/down [the original presenting issue].
Remember, this was a very intermittent problem. This is with rebuilt ECU installed. The car did not experience any revving for about a week. Then, AFTER being warm, on a re-start, it revved up/ down, but idle stabilized in several seconds. Subsequently, DAYS apart, I’ve had two other occurrences of the revving up/down. Both times this stabilized or “self-corrected” within about a minute. The self-correcting behavior has NEVER occurred prior to the ECU repair. So, that's somewhat good news.
The strangest part is what follows. Makes for a great story, but not so much as a car owner. And, I dared not post this until it was confirmed by others who heard it.
I started to hear a defintive lurching or clunking sound near the front end of the car. It sounds like there’s something “off” or loose on the front end of the car. [You'd "think" suspension...].
Critically, when driving, when I let my foot OFF the gas, especiallyl at low speeds, the car makes a definitive lurching or clunking sound, maybe one or two such sounds in a row. Also, and possibly related, if I’m driving at moderate speed, I’ll hear a minor clunk as I let my foot off the gas and again as I start to accelerate. It's very brief. In general, the pickup is great, and the transmission upshift is great.
Now, the most bizarre part. This new noise has been going on CONSISTENTLY since about the time of the ECU repair. However, twice, after driving more than about 20 miles, the sound decreased dramatically. [Yes, I know this sounds weird!]. I drove with two friends in the car last night. They CLEARLY heard all these sounds. And, the same night, after driving about 15 miles, I could barely get the sound to re-occur. My friends both heard the original noise and the change and agreed they could barely hear any noise.
I have no idea what’s going on. Discussing “intermittent” sounds, especially this “clunking” sound seems nuts. But it is what it is. And, other people heard the same sounds and the same changes.
What’s left to check?
Vaccuum lines? I’ll gladly look it up and aim to replace them all.
TPS? Well, I don’t really know how to adjust it.
Air Idle Control Valve? Well, I did take it out and clean it months ago with no audible change, no change to revving issue. Did I do it incorrectly? Could the AIC actually be faulty?
Oxygen sensor. Someone posted that the oxygen sensors could cause a clunking sound. Which ones? Wouldn’t I get a CEL if they were bad?
LAC bushings? A great forum member checked them with me. Both LAC bushings are a bit worn.
BUT, how could that cause such a inconsistent sound? Appears then disappears?
I’m open to suggestions, starting with desiring to “rule out” issues.
THANK YOU.
BTW, the car ran almost flawlessly for 3 years. Yes, there were repairs, but nothing that unusual.
And, "odd sounds" were readily attributable to obvious things like a bad steering pump.
Since repairing and re-installing the ECU, the following occurred:
A few times, consecutively on different days, the car would start, but then stall. Re-start = stall again. I’d finally have to start and lightly rev the engine for about a minute. Then, the car did not stall. Subsequent re-starts when the car was already warm = great. This happened about 5 times and has not re-occurred. In fact, surprisingly, it started without a hitch on a cold morning.
Reviing up/down [the original presenting issue].
Remember, this was a very intermittent problem. This is with rebuilt ECU installed. The car did not experience any revving for about a week. Then, AFTER being warm, on a re-start, it revved up/ down, but idle stabilized in several seconds. Subsequently, DAYS apart, I’ve had two other occurrences of the revving up/down. Both times this stabilized or “self-corrected” within about a minute. The self-correcting behavior has NEVER occurred prior to the ECU repair. So, that's somewhat good news.
The strangest part is what follows. Makes for a great story, but not so much as a car owner. And, I dared not post this until it was confirmed by others who heard it.
I started to hear a defintive lurching or clunking sound near the front end of the car. It sounds like there’s something “off” or loose on the front end of the car. [You'd "think" suspension...].
Critically, when driving, when I let my foot OFF the gas, especiallyl at low speeds, the car makes a definitive lurching or clunking sound, maybe one or two such sounds in a row. Also, and possibly related, if I’m driving at moderate speed, I’ll hear a minor clunk as I let my foot off the gas and again as I start to accelerate. It's very brief. In general, the pickup is great, and the transmission upshift is great.
Now, the most bizarre part. This new noise has been going on CONSISTENTLY since about the time of the ECU repair. However, twice, after driving more than about 20 miles, the sound decreased dramatically. [Yes, I know this sounds weird!]. I drove with two friends in the car last night. They CLEARLY heard all these sounds. And, the same night, after driving about 15 miles, I could barely get the sound to re-occur. My friends both heard the original noise and the change and agreed they could barely hear any noise.
I have no idea what’s going on. Discussing “intermittent” sounds, especially this “clunking” sound seems nuts. But it is what it is. And, other people heard the same sounds and the same changes.
What’s left to check?
Vaccuum lines? I’ll gladly look it up and aim to replace them all.
TPS? Well, I don’t really know how to adjust it.
Air Idle Control Valve? Well, I did take it out and clean it months ago with no audible change, no change to revving issue. Did I do it incorrectly? Could the AIC actually be faulty?
Oxygen sensor. Someone posted that the oxygen sensors could cause a clunking sound. Which ones? Wouldn’t I get a CEL if they were bad?
LAC bushings? A great forum member checked them with me. Both LAC bushings are a bit worn.
BUT, how could that cause such a inconsistent sound? Appears then disappears?
sounds like the issue I had on my first SC. It sounded like someone was hitting a stick undrneath the car by the console, literally. Even an aauto mechanic said it could be something mechanical, like the tranny mount. I replaced it and it didn't fix it. The car would buck and kick when slight throttle was used or it was coasting at 40. It ended up being bad o2 sensors.
THANK YOU.
Last edited by Idrive70; 11-16-14 at 06:32 PM.
11-16-14, 06:10 PM
#23
Lexus Test Driver
Have you checked your coolant level? When I revs bouncing like that, it was due to low level of coolant and too much air in the cooling system. That would have been the first thing I checked. It would just pulse/rev-bounce when warming up or idle/not driving. Maybe try purging the air out of your radiator and cooling system before you continue to spend more money because I haven't read that that was done yet
11-16-14, 06:13 PM
#24
Oxygen sensor. Someone posted that the oxygen sensors could cause a clunking sound. Which ones? Wouldn’t I get a CEL if they were bad?
LAC bushings? A great forum member checked them with me. Both LAC bushings are a bit worn.
BUT, how could that cause such a inconsistent sound? Appears then disappears? I’m open to suggestions, starting with desiring to “rule out” issues.
THANK YOU.
LAC bushings? A great forum member checked them with me. Both LAC bushings are a bit worn.
BUT, how could that cause such a inconsistent sound? Appears then disappears? I’m open to suggestions, starting with desiring to “rule out” issues.
THANK YOU.
11-19-14, 09:44 AM
#25
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What guy in Atlanta? I live in Atlanta and I think I need to get this done. Send me the name of his shop or just PM his contact info. I'm thinking my caps are bad and need replaced. My 1992 SC400 is having a similar idling issue. Intermittent RPM fluctuation. Mine feels like a misfire though, but other people on the forum have recommended the ECU rebuild route as a possible solution. Is there any way I can test the ECU? I think I remember someone saying you can visually tell by looking at the caps and seeing if they have some corrosion or arcing burns or something like that???
11-21-14, 09:53 AM
#26
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What guy in Atlanta? I live in Atlanta and I think I need to get this done. Send me the name of his shop or just PM his contact info. I'm thinking my caps are bad and need replaced. My 1992 SC400 is having a similar idling issue. Intermittent RPM fluctuation. Mine feels like a misfire though, but other people on the forum have recommended the ECU rebuild route as a possible solution. Is there any way I can test the ECU? I think I remember someone saying you can visually tell by looking at the caps and seeing if they have some corrosion or arcing burns or something like that???
11-21-14, 03:04 PM
#27
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open up ecu and if leaking you should be able to see stains around them. Ecu rebuild and navigation repair Darryl Geller 4020 Two Rivers Dr Cumming Ga. 30041 404-550-7511 Make sure to send your info with phone number. Thanks Darryl. That's his info. Great guy. Lifetime warranty also
11-22-14, 03:59 AM
#28
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like around a week. Also sometimes the caps might seem good and still be bad. I'd still rebuild it. Also he check out the ecu and if it doesn't need work hell return it. If that helps since he's the expert.
12-04-14, 06:30 AM
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My understanding is that these caps will simply "go bad" after a number of years. Yes, "leaking" is the obvious sign, but they could still be bad and not be leaking. I'm no expert on this topic, but all I've read suggests they should be replaced. I didn't see any leakage on mine, but was informed the board tested bad and caps were replaced.
12-04-14, 09:58 AM
#30
My understanding is that these caps will simply "go bad" after a number of years. Yes, "leaking" is the obvious sign, but they could still be bad and not be leaking. I'm no expert on this topic, but all I've read suggests they should be replaced. I didn't see any leakage on mine, but was informed the board tested bad and caps were replaced.
*Not my pictures*