Annoying problem idle problem in my 1st gen LS
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Annoying problem idle problem in my 1st gen LS
Okay this problem has been on going on my LS for...well i lost count because its been that long.
Problem -
Car can't idle. When you come to a stop or under 10mph and not giving the car ANY gas, even a slight step on the pedal, the RPMs will just drop and the car will die. ON gas, the car drives normal and can make it home if there is not stop and go...basically can't come to a stop and idle.
What I noticed -
This problem ONLY happens 10-15% of the time I drive the car..so its random and unexpecting
Also, I noticed it happened more when it was raining rather than dry weather conditions.
only has this problem at operating temperature, never when cold or warm.
when car DOESNT have this problem and comes to a stop, it has a low idle, maybe 400-450rpms and the needle on the tach is very shaky.. hard to explain. The needle vibrates as it has a slight rough idle like its having a hard time to idle till gas applied.
when driving with no problems and coming to a stop..i notice the RPM needle dip down to 400rpms before a complete stop and something adjusts and brings the idle back up to around 1000rpms then back to 400-500rpms when the car eventually reaches a complete stop and just sits there.
when the car dies, i can start it right back up with NO issues and it just dies again if not applying gas
What i know about the car -
1990 ls400
240+ miles
cracked intake pipe, fixed with silicone but i doubt its 100% sealed.
EGR tube is cracked
help help help..im stumped...car drives fine and wish it could be reliable as the old days. Car runs perfectly when these issues aren't happening..
I know its a handfull to read but let me know what you guys think
Thanks
Problem -
Car can't idle. When you come to a stop or under 10mph and not giving the car ANY gas, even a slight step on the pedal, the RPMs will just drop and the car will die. ON gas, the car drives normal and can make it home if there is not stop and go...basically can't come to a stop and idle.
What I noticed -
This problem ONLY happens 10-15% of the time I drive the car..so its random and unexpecting
Also, I noticed it happened more when it was raining rather than dry weather conditions.
only has this problem at operating temperature, never when cold or warm.
when car DOESNT have this problem and comes to a stop, it has a low idle, maybe 400-450rpms and the needle on the tach is very shaky.. hard to explain. The needle vibrates as it has a slight rough idle like its having a hard time to idle till gas applied.
when driving with no problems and coming to a stop..i notice the RPM needle dip down to 400rpms before a complete stop and something adjusts and brings the idle back up to around 1000rpms then back to 400-500rpms when the car eventually reaches a complete stop and just sits there.
when the car dies, i can start it right back up with NO issues and it just dies again if not applying gas
What i know about the car -
1990 ls400
240+ miles
cracked intake pipe, fixed with silicone but i doubt its 100% sealed.
EGR tube is cracked
help help help..im stumped...car drives fine and wish it could be reliable as the old days. Car runs perfectly when these issues aren't happening..
I know its a handfull to read but let me know what you guys think
Thanks
#2
my car did the same thing, exactly. I was going to replace the tps (throttle position sensor) but just took it off, blew the dust off of it, reinstalled.
has not happened again in over 20k miles.
try it!
has not happened again in over 20k miles.
try it!
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I knew it was a simple fix!! ill try it today and let you guys know the outcome
#4
If you remove the TPS ensure you mark the original position so it goes back in exactly the same place or it will need setting back up again.
Look below for details
http://www.lexls.com/tutorials/EFI/tps.html
There are 2 other possibles for the idle fault one is the throttle body itself gummed up which needs cleaning.
Look at link below for details
http://www.lexls.com/tutorials/EFI/throttlebody.html
The other possibility is the ICV ( idle control valve)
Look below for details
http://www.lexls.com/tutorials/EFI/tps.html
There are 2 other possibles for the idle fault one is the throttle body itself gummed up which needs cleaning.
Look at link below for details
http://www.lexls.com/tutorials/EFI/throttlebody.html
The other possibility is the ICV ( idle control valve)
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Im going to do these in order to see if it fixes the problem
1) Clean and Adjust TPS
2) Replace TPS
3) Clean Throttle Body
4) Check/clean/replace ICV
1) Clean and Adjust TPS
2) Replace TPS
3) Clean Throttle Body
4) Check/clean/replace ICV
#6
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#8
Okay this problem has been on going on my LS for...well i lost count because its been that long.
Problem -
Car can't idle. When you come to a stop or under 10mph and not giving the car ANY gas, even a slight step on the pedal, the RPMs will just drop and the car will die. ON gas, the car drives normal and can make it home if there is not stop and go...basically can't come to a stop and idle.
What I noticed -
This problem ONLY happens 10-15% of the time I drive the car..so its random and unexpecting
Also, I noticed it happened more when it was raining rather than dry weather conditions.
only has this problem at operating temperature, never when cold or warm.
when car DOESNT have this problem and comes to a stop, it has a low idle, maybe 400-450rpms and the needle on the tach is very shaky.. hard to explain. The needle vibrates as it has a slight rough idle like its having a hard time to idle till gas applied.
when driving with no problems and coming to a stop..i notice the RPM needle dip down to 400rpms before a complete stop and something adjusts and brings the idle back up to around 1000rpms then back to 400-500rpms when the car eventually reaches a complete stop and just sits there.
when the car dies, i can start it right back up with NO issues and it just dies again if not applying gas
What i know about the car -
1990 ls400
240+ miles
cracked intake pipe, fixed with silicone but i doubt its 100% sealed.
EGR tube is cracked
help help help..im stumped...car drives fine and wish it could be reliable as the old days. Car runs perfectly when these issues aren't happening..
I know its a handfull to read but let me know what you guys think
Thanks
Problem -
Car can't idle. When you come to a stop or under 10mph and not giving the car ANY gas, even a slight step on the pedal, the RPMs will just drop and the car will die. ON gas, the car drives normal and can make it home if there is not stop and go...basically can't come to a stop and idle.
What I noticed -
This problem ONLY happens 10-15% of the time I drive the car..so its random and unexpecting
Also, I noticed it happened more when it was raining rather than dry weather conditions.
only has this problem at operating temperature, never when cold or warm.
when car DOESNT have this problem and comes to a stop, it has a low idle, maybe 400-450rpms and the needle on the tach is very shaky.. hard to explain. The needle vibrates as it has a slight rough idle like its having a hard time to idle till gas applied.
when driving with no problems and coming to a stop..i notice the RPM needle dip down to 400rpms before a complete stop and something adjusts and brings the idle back up to around 1000rpms then back to 400-500rpms when the car eventually reaches a complete stop and just sits there.
when the car dies, i can start it right back up with NO issues and it just dies again if not applying gas
What i know about the car -
1990 ls400
240+ miles
cracked intake pipe, fixed with silicone but i doubt its 100% sealed.
EGR tube is cracked
help help help..im stumped...car drives fine and wish it could be reliable as the old days. Car runs perfectly when these issues aren't happening..
I know its a handfull to read but let me know what you guys think
Thanks
I went through that too w/ my '92 ls4. What I did was focus just on Shell premium gas. That helped alot. Watch the gas you're putting in there. It would help to repair the cracked intake pipe properly, and the EGR tube. Also, have your fuel system, fuel injectors, and mass air flow sensor checked. Did you have a major tune-up? Make sure you have a trusted, well-qualified mechanic. Follow through with the other good advice on here and you'll be fine. Treat this car right and it will treat you right.
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no check engine light but sometimes the trac light and check engine light come on at the same time and turn off at the same time. This happens like 50% of the time when i drive the car but nothing happens to the car. It drives normal when it happens so i never really bothered.
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ive cleaned the TPS and no problems since..idle does dip down low sometimes(200-300rpms) but has not died on me since. I think my TPS is on its way out.
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