1998 Ls400 Low Idle Dies When Warm Except W Ac On
11-15-14, 01:19 AM
#31
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Yamae! This is EXACTLY my issue. You've described my shifting/driving experience perfectly. So this is my ecu caps causing the issue or dirty TB? Could it be possible my mechanic was wrong about my tach being inaccurate?
11-15-14, 02:46 AM
#32
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I'm not a mechanic nor a shop owner but I know some of the behind scene of Toyota cars. I have several friends who run independent repair shops. They call me up time to time when their mechanics encounter complicated electronics related problems. You can't expect a lot to average mechanics when you need to fix your LS400. May be you should hire me.
Last edited by Yamae; 11-15-14 at 03:06 AM.
02-07-15, 01:39 AM
#35
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UPDATE**
i did a few things to no avail, so for those of you with the same issue, don't expect this stuff to work...
1. cleaned MAF
2. Cleaned TB/ air mix path
3. Cleaned entire intake plenum
4. ran fuel system cleaner
5. cleaned OCV's and chambers, tested plungers for movement, seemed fine
6. cleared codes for intermittent CEL (bank 1 running too lean), they have not come back.
The one and only difference i have noticed is that the ticking at idle is gone.
The tranny surge that yamae mentioned has not been helped at all by the cleaning.
Car with lights/ AC off/ warm/ in D idles at ~200 rpm and rough if i turn on the lights or AC it smoothes out (not entirely) and idles up to ~400 rpm.
one thing i have noticed is that my tape deck keeps popping out up until about a half hour of highway driving. after that it doesn't pop out at all. i think the low idle is undercharging the battery (i hope) causing the tape to eject at random. OR maybe its a parasitic drain somewhere thats causing the low idle in the first place.
The only other thing i can think of would be a vacuum leak, but i had an experienced mechanic listen to the engine and he said there were absolutely no leaks, wouldn't even let me pay him for a definitive test.
Im at my wits end here and i refuse to give up and take it to the dealer. any ideas on what i should look at next??
i did a few things to no avail, so for those of you with the same issue, don't expect this stuff to work...
1. cleaned MAF
2. Cleaned TB/ air mix path
3. Cleaned entire intake plenum
4. ran fuel system cleaner
5. cleaned OCV's and chambers, tested plungers for movement, seemed fine
6. cleared codes for intermittent CEL (bank 1 running too lean), they have not come back.
The one and only difference i have noticed is that the ticking at idle is gone.
The tranny surge that yamae mentioned has not been helped at all by the cleaning.
Car with lights/ AC off/ warm/ in D idles at ~200 rpm and rough if i turn on the lights or AC it smoothes out (not entirely) and idles up to ~400 rpm.
one thing i have noticed is that my tape deck keeps popping out up until about a half hour of highway driving. after that it doesn't pop out at all. i think the low idle is undercharging the battery (i hope) causing the tape to eject at random. OR maybe its a parasitic drain somewhere thats causing the low idle in the first place.
The only other thing i can think of would be a vacuum leak, but i had an experienced mechanic listen to the engine and he said there were absolutely no leaks, wouldn't even let me pay him for a definitive test.
Im at my wits end here and i refuse to give up and take it to the dealer. any ideas on what i should look at next??
02-07-15, 07:19 AM
#36
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http://blogs.yahoo.co.jp/ks1106spiderman/1099329.html
A badly clogged air mix path often clogs injectors too and you need to clean them professionally.
02-07-15, 10:05 AM
#37
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I cleaned out the AMP extremely thoroughly. So if I gave a mechanic who reads Japanese that link my problems will be solved?
Is this link for low idle or the surging around corners and off the line?
Is this link for low idle or the surging around corners and off the line?
02-07-15, 06:09 PM
#38
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In case you don't find anyone, I just will summarize the contents. The important part is to clean injector's side passages where only the air goes in using a special cleaning machine for Toyota's air assisting injectors. Those passages can't be cleaned by a regular method. A badly clogged air mix path at the throttle body sometimes causes completely blocked injector's air passage at the side.
02-08-15, 01:53 AM
#39
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Yamae thanks again for the info. Another thing I'd like to add is I'm getting great gas mileage. About 18 mpg in LA traffic and on the highway I returned 29.5 for a 400 mile round trip. Plus the car has tons of power just idles at 200 rpm. All other aspects seem perfect
02-10-15, 04:49 PM
#41
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Mattylex,
I had a really bad transmission surge problem when slowing down to round corners as well as when coasting all the way to a red then it turning green right before you get there. You ever so gently start to accelerate and it feels like transmission is free spooling then WAM it catches almost like you were learning how to drive stick all over again
.
Anyway, it took a while for me but cleaning the air passage ways really does do the trick. Forget about the stupid 8 small ones that go down into the Throttle Body, really focus on the two larger ones. I mean get the Throttle Body cleaner straw as far as it'll go into those things and all around and just keep spraying. Use a couple of bottles if you have to. I used CRC's cleaner for reference. I then shot some compressed air into those bigger holes as well as continued to absolutely drench them with the cleaner, again, getting the straw as far back in there as I could.
When I went to start it up; it wouldn't. I had to continue to crank it while pumping the gas pedal and then holding it all the way down until it caught and then once it catches keep your foot on the gas just enough for it to idle pretty high for 5 seconds around 1800RPM or so.
I understand that this isn't a carburated engine and the whole blah blah blah the pedal pumping and holding does nothing because of technology A and B.
I'm simply stating what I did that worked for me. Unfortunately, I do not know enough about engines and fuel/air systems to explain why or how it works. I hope to be there one day, but that is neither here nor there.
As Stiller says in the movie Heavy Weights, "Do it to it Lars!".
Send me a PM and I can help further if needed.
Matt
I had a really bad transmission surge problem when slowing down to round corners as well as when coasting all the way to a red then it turning green right before you get there. You ever so gently start to accelerate and it feels like transmission is free spooling then WAM it catches almost like you were learning how to drive stick all over again
.Anyway, it took a while for me but cleaning the air passage ways really does do the trick. Forget about the stupid 8 small ones that go down into the Throttle Body, really focus on the two larger ones. I mean get the Throttle Body cleaner straw as far as it'll go into those things and all around and just keep spraying. Use a couple of bottles if you have to. I used CRC's cleaner for reference. I then shot some compressed air into those bigger holes as well as continued to absolutely drench them with the cleaner, again, getting the straw as far back in there as I could.
When I went to start it up; it wouldn't. I had to continue to crank it while pumping the gas pedal and then holding it all the way down until it caught and then once it catches keep your foot on the gas just enough for it to idle pretty high for 5 seconds around 1800RPM or so.
I understand that this isn't a carburated engine and the whole blah blah blah the pedal pumping and holding does nothing because of technology A and B.
I'm simply stating what I did that worked for me. Unfortunately, I do not know enough about engines and fuel/air systems to explain why or how it works. I hope to be there one day, but that is neither here nor there.
As Stiller says in the movie Heavy Weights, "Do it to it Lars!".
Send me a PM and I can help further if needed.
Matt
02-10-15, 06:13 PM
#42
Moderator
MngreLMatt, you explained things very well and also the way to shoot some compressed air into those bigger holes is a good idea to try before removing and cleaning injectors. My limited English is not good enough to explain things but now there will be many who can be helped reading your post. Aged 98-00 will have this problem 100%, I can say.
The attached drawing is the lower part of the injector. It handles not only the fuel but also the air at the side. A badly clogged throttle body often clogs injector's air mix path. You often need a whole can of cleaner or more to clean the path. To use a compressed air is a nice idea. I must try your method next time when I help someone to clean. In the past, all the people whom I helped were successful and happy except 1 which required to remove injectors. I should have tried your method first.
The attached drawing is the lower part of the injector. It handles not only the fuel but also the air at the side. A badly clogged throttle body often clogs injector's air mix path. You often need a whole can of cleaner or more to clean the path. To use a compressed air is a nice idea. I must try your method next time when I help someone to clean. In the past, all the people whom I helped were successful and happy except 1 which required to remove injectors. I should have tried your method first.
Last edited by Yamae; 02-10-15 at 06:16 PM.
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02-10-15, 08:41 PM
#43
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Yamae thanks again for the info. Another thing I'd like to add is I'm getting great gas mileage. About 18 mpg in LA traffic and on the highway I returned 29.5 for a 400 mile round trip. Plus the car has tons of power just idles at 200 rpm. All other aspects seem perfect
? how did u got this MPG now
?
02-11-15, 10:24 AM
#44
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i once did this and i really can't say it made much of a difference, but then again i might not have sprayed enough / may not have even had much of a problem in the first place. would using some sort of pipe cleaner in the two larger holes also work? i just feel like that would do a better cleaning job and i just don't feel entirely comfortable about spraying that much fluid into the intake that that. is it possible that the injectors themselves may need cleaning / replacement?
02-11-15, 11:03 PM
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MngreLMatt, you explained things very well and also the way to shoot some compressed air into those bigger holes is a good idea to try before removing and cleaning injectors. My limited English is not good enough to explain things but now there will be many who can be helped reading your post. Aged 98-00 will have this problem 100%, I can say.
The attached drawing is the lower part of the injector. It handles not only the fuel but also the air at the side. A badly clogged throttle body often clogs injector's air mix path. You often need a whole can of cleaner or more to clean the path. To use a compressed air is a nice idea. I must try your method next time when I help someone to clean. In the past, all the people whom I helped were successful and happy except 1 which required to remove injectors. I should have tried your method first.
The attached drawing is the lower part of the injector. It handles not only the fuel but also the air at the side. A badly clogged throttle body often clogs injector's air mix path. You often need a whole can of cleaner or more to clean the path. To use a compressed air is a nice idea. I must try your method next time when I help someone to clean. In the past, all the people whom I helped were successful and happy except 1 which required to remove injectors. I should have tried your method first.
it is like cleaning car's nose, so it can run faster and breath better!
will monitor MPG to see if i get any improvements...
Thanks Yamae
