1998 Ls400 Low Idle Dies When Warm Except W Ac On
02-12-15, 06:03 PM
#46
Rookie
Join Date: May 2014
Location: CA
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
29.5 mpg for a vvti ls400 isn't crazy on all HWY just look at the gas mileage thread.
thanks for the info ill try that matt.
im wondering if you had the same low/rough idle that i do.
lately when i first start the car in the morning my tape player keeps ejecting the tape at random, for the first 15 minutes of driving. then for the rest of the day it is perfect.
Also after i drive in traffic with the AC on and i go to lock my car the lights don't flash and the locks cycle at random or lock 3 and not 4 doors etc.
These issues sound like a dead battery but i just replaced it 2 months ago after having similar more severe issues, which were fixed for a short time. now they are coming back.
im thinking the low idle is not charging the battery, or maybe its something else
any suggestions?????
?thanks for the info ill try that matt.
im wondering if you had the same low/rough idle that i do.
lately when i first start the car in the morning my tape player keeps ejecting the tape at random, for the first 15 minutes of driving. then for the rest of the day it is perfect.
Also after i drive in traffic with the AC on and i go to lock my car the lights don't flash and the locks cycle at random or lock 3 and not 4 doors etc.
These issues sound like a dead battery but i just replaced it 2 months ago after having similar more severe issues, which were fixed for a short time. now they are coming back.
im thinking the low idle is not charging the battery, or maybe its something else
any suggestions?????
02-12-15, 07:13 PM
#47
Moderator
These issues sound like a dead battery but i just replaced it 2 months ago after having similar more severe issues, which were fixed for a short time. now they are coming back.
im thinking the low idle is not charging the battery, or maybe its something else
any suggestions?????
im thinking the low idle is not charging the battery, or maybe its something else
any suggestions?????
02-12-15, 10:33 PM
#48
Driver
Join Date: Oct 2013
Location: CA
Posts: 139
Likes: 0
Received 0 Likes
on
0 Posts
Matty, I don't get stalling with mine yet. Although mine does idle really low. Most times around 400 but sometimes less and let me tell you that with my worn engine mounts and that low idle there is a major vibration factor.
Doing all of this cleaning hasn't done a bit for the idle, it has eradicated my transmission surge if we should start calling it that to keep terminology consistent for those following and future followers.
Doing all of this cleaning hasn't done a bit for the idle, it has eradicated my transmission surge if we should start calling it that to keep terminology consistent for those following and future followers.
02-19-15, 01:48 PM
#49
Ok, so I took two full cans of crc throttle body cleaner and cleaned each big hole by sticking the little hose as far in as it would go with the engine running and pulling the throttle cable to keep the engine from stalling.
Tranny surge is still there. Idle is still abysmal. 400 no a/c, no lights. 600 with lights. Mpg is terrible. 17-18 Highway. On a 2nd gen!
Tranny surge is still there. Idle is still abysmal. 400 no a/c, no lights. 600 with lights. Mpg is terrible. 17-18 Highway. On a 2nd gen!
02-20-15, 07:22 AM
#50
Lead Lap
Ok, so I took two full cans of crc throttle body cleaner and cleaned each big hole by sticking the little hose as far in as it would go with the engine running and pulling the throttle cable to keep the engine from stalling.
Tranny surge is still there. Idle is still abysmal. 400 no a/c, no lights. 600 with lights. Mpg is terrible. 17-18 Highway. On a 2nd gen!
Tranny surge is still there. Idle is still abysmal. 400 no a/c, no lights. 600 with lights. Mpg is terrible. 17-18 Highway. On a 2nd gen!
35000-50110
these might help...
02-23-15, 06:44 PM
#52
Lead Lap
02-24-15, 09:22 AM
#53
Rookie
Join Date: May 2014
Location: CA
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
Cleaned the amp the way you said and blew some air into it. Car shifts/ accelerates waaaaaaay better. Interestingly I drove the car a bit with the plate off just after I cleaned it, it raised and improved the idle could this be something to do with MAF?When I put it back on the idle dropped to 200 again
02-24-15, 09:25 AM
#54
Driver
Join Date: Oct 2013
Location: CA
Posts: 139
Likes: 0
Received 0 Likes
on
0 Posts
RuGby dad,
It's too hard for me to show the exact procedure I did on mine. Quick question, when you went to start it up after the cleaning would it? I also shot compressed air through the holes with the cleaner still in there with the hopes that it would force the cleaner through the injectors and thus cleaning them. The air mix cavities of the injector that yamae posted make it even more clear to me now that these need to be clean.
Another thing, if you're only returning 17-18 highway with your tires properly inflated then you've got bigger problems. I can't tell you what your bigger problem is, but the mpg is a big sign that you have something else going on.
Have you replaced the electronic coolant temperature sensor(ECT)? Please correct me if that's not what it stands for.
We'll need to know a host of other things before it would be worth throwing money at
Matt
It's too hard for me to show the exact procedure I did on mine. Quick question, when you went to start it up after the cleaning would it? I also shot compressed air through the holes with the cleaner still in there with the hopes that it would force the cleaner through the injectors and thus cleaning them. The air mix cavities of the injector that yamae posted make it even more clear to me now that these need to be clean.
Another thing, if you're only returning 17-18 highway with your tires properly inflated then you've got bigger problems. I can't tell you what your bigger problem is, but the mpg is a big sign that you have something else going on.
Have you replaced the electronic coolant temperature sensor(ECT)? Please correct me if that's not what it stands for.
We'll need to know a host of other things before it would be worth throwing money at
Matt
02-24-15, 01:14 PM
#55
RuGby dad,
It's too hard for me to show the exact procedure I did on mine. Quick question, when you went to start it up after the cleaning would it? I also shot compressed air through the holes with the cleaner still in there with the hopes that it would force the cleaner through the injectors and thus cleaning them. The air mix cavities of the injector that yamae posted make it even more clear to me now that these need to be clean.
Another thing, if you're only returning 17-18 highway with your tires properly inflated then you've got bigger problems. I can't tell you what your bigger problem is, but the mpg is a big sign that you have something else going on.
Have you replaced the electronic coolant temperature sensor(ECT)? Please correct me if that's not what it stands for.
We'll need to know a host of other things before it would be worth throwing money at
Matt
It's too hard for me to show the exact procedure I did on mine. Quick question, when you went to start it up after the cleaning would it? I also shot compressed air through the holes with the cleaner still in there with the hopes that it would force the cleaner through the injectors and thus cleaning them. The air mix cavities of the injector that yamae posted make it even more clear to me now that these need to be clean.
Another thing, if you're only returning 17-18 highway with your tires properly inflated then you've got bigger problems. I can't tell you what your bigger problem is, but the mpg is a big sign that you have something else going on.
Have you replaced the electronic coolant temperature sensor(ECT)? Please correct me if that's not what it stands for.
We'll need to know a host of other things before it would be worth throwing money at
Matt
And actually my mpg has dropped to 15mpg highway. Hurts my feelings. Also my transmission fluid is a little low. It's not at the high side of hot. It's a little higher than middle. So I'll refill that as well after I take a drive tomorrow.
02-24-15, 08:01 PM
#56
Driver
Join Date: Oct 2013
Location: CA
Posts: 139
Likes: 0
Received 0 Likes
on
0 Posts
I left the car running the entire time, pulling the throttle cable to keep it on. I didn't use any compressed air either. I have replaced the ect. I haven't done the full diagnostics or a proper tune up yet, so I'm still hopeful it's either a o2 sensor or the spark plugs etc. So what I'll probably do tomorrow is buy two more cans of throttle cleaner and some compressed air and let the engine die as I spray.
And actually my mpg has dropped to 15mpg highway. Hurts my feelings. Also my transmission fluid is a little low. It's not at the high side of hot. It's a little higher than middle. So I'll refill that as well after I take a drive tomorrow.
And actually my mpg has dropped to 15mpg highway. Hurts my feelings. Also my transmission fluid is a little low. It's not at the high side of hot. It's a little higher than middle. So I'll refill that as well after I take a drive tomorrow.
Matty glad to hear you're doing much better with your car. It is so nice to drive and have confidence in your car. It makes all the difference for me at least.
Cool little thing when you shoot the compressed air in there on each side you can actually see the fuel injectors jiggle a little bit - kind of cool.
Just to say again what I have already: with the car off , I spray the cleaner all around the inside of those holes. This, only after the throttle plate and inner throttle body is spotless. I pool the cleaner in those holes ultimately flooding the air pathway. After you go a little overboard with the flooding shoot some compressed air in those two holes.
Hope this helps.
I'll stay tuned
Because just about everyone will have a problem with this at some point I ought to make a good DIY video for it.
Until next time,
Matt
02-24-15, 08:08 PM
#57
Driver
Join Date: Oct 2013
Location: CA
Posts: 139
Likes: 0
Received 0 Likes
on
0 Posts
Are there more problems accompanying your gas mileage? Does the car take a while to warm up? Does it warm up all the way?
I know the EGR vavle is a problem in sub 98-00 model years.
As for the spark plugs I changed mine at 200k and they surely didn't look bad and my mileage didn't change.
Just a few thoughts
Matt
I know the EGR vavle is a problem in sub 98-00 model years.
As for the spark plugs I changed mine at 200k and they surely didn't look bad and my mileage didn't change.
Just a few thoughts
Matt
02-24-15, 10:00 PM
#58
Moderator
The reason why the car should be on is to get the negative pressure of around -0.65 atm and the continuous air flow to injectors. Pistons and the cylinders make the negative pressure and the cleaning solvent is absorbed to cylinders through the air mix paths while those are working.
04-22-15, 12:23 PM
#59
I tried to spray the carb cleaner through the two big holes with the engine off but the fluid just kept coming back out and flowing down into the throttle body.
Car takes no time to warm up. 5-10 minutes max. 87k miles 2000 ls400. I took the intake off again to clean the throttle body plate and it was almost perfectly clean since I last did it about 5k miles ago. No misfiring, no CEL, no nothing except for a slight vibration which I'm sure is the mounts (ordered and on their way).
Car still jolts forward when slowing down then stepping on the gas especially when accelerating after a turn.
My next option is to get a professional ultrasonic injection cleaning and a professional throttle body cleaning. My hope is they take the throttle body completely off and clean behind it as well, as this is something I'm a bit afraid to do.
I can't imagine what else it could be as yamae has pretty much concluded that this lurching is a result of a dirty throttle body or fuel injectors.
Car takes no time to warm up. 5-10 minutes max. 87k miles 2000 ls400. I took the intake off again to clean the throttle body plate and it was almost perfectly clean since I last did it about 5k miles ago. No misfiring, no CEL, no nothing except for a slight vibration which I'm sure is the mounts (ordered and on their way).
Car still jolts forward when slowing down then stepping on the gas especially when accelerating after a turn.
My next option is to get a professional ultrasonic injection cleaning and a professional throttle body cleaning. My hope is they take the throttle body completely off and clean behind it as well, as this is something I'm a bit afraid to do.
I can't imagine what else it could be as yamae has pretty much concluded that this lurching is a result of a dirty throttle body or fuel injectors.
