Please help - Stuttering engine
03-08-13, 04:19 PM
#1
Lead Lap
Thread Starter
Please help - Stuttering engine
I have a 1992 LS400 about 300k miles. Today I drove to work with no problems at all.
After Work while driving home at about 2,500 rpm I got a stutter from the engine. The stuttering got worse and worse within .5 mile. Finally at a red light the stuttering continued and the car died. Started just fine and died again at the next light. Drove back to work and left the car there. The stuttering made the car undrivable the stuttering caused the car to jerk violently and died at every light on the way back to work. Also no check engine light has come on.
This problem came out of nowhere and has run fine since I bought the car.
I would really appreciate any input and help. Thank you
After Work while driving home at about 2,500 rpm I got a stutter from the engine. The stuttering got worse and worse within .5 mile. Finally at a red light the stuttering continued and the car died. Started just fine and died again at the next light. Drove back to work and left the car there. The stuttering made the car undrivable the stuttering caused the car to jerk violently and died at every light on the way back to work. Also no check engine light has come on.
This problem came out of nowhere and has run fine since I bought the car.
I would really appreciate any input and help. Thank you
Last edited by RA40; 03-08-13 at 05:43 PM. Reason: descriptive title
03-08-13, 05:28 PM
#4
Lead Lap
Thread Starter
new t-belt. checked spark plug wires. they look new as well. only had about 30 min to check though. oil change about 2k ago. runs fine other than this. seems worse after warm up
03-08-13, 05:43 PM
#6
ALL LS400s have a Throttle Position Sensor, regardless of TRAC or not. I'm just throwing it out because i had both my 4Runner and Landcruiser do similar things once, and it turned out to be the TPS on both of them.
The sensors themselves were okay, so no code was thrown, but their internals wear out and they stick open, which tells the ECU to dump in too much gas with the throttle shut and screw everything up.
The sensors themselves were okay, so no code was thrown, but their internals wear out and they stick open, which tells the ECU to dump in too much gas with the throttle shut and screw everything up.
03-08-13, 05:45 PM
#7
Lead Lap
Thread Starter
Would that cause it to stall? Sounds like a good thing to check. I've also thought about the fuel filter and dirty injectors. Just don't have enough money for trial and error
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03-09-13, 02:15 PM
#10
Lead Lap
Thread Starter
during idle the rpms drop and stutter and will eventually stall. when you gradually give it gas the rpms rise and jump 50-100rpms.
Posted from ClubLexus.com App for Android
Posted from ClubLexus.com App for Android
03-10-13, 03:29 AM
#11
Lexus Champion
just to ask a couple of basics - what is the voltage across the battery with a multimeter with car off and car on at idle. should be at least 12.5V and 13.6V respectively at least, otherwise you have a battery or alternator problem, which will make the car run like crap or not at all
otherwise, please go here and follow the simple procedure and download the OBD-I codes so we can better assist you - just because there is no check engine light, doesn't mean there are no stored codes!
many things can cause this type of problem, a bad fuel pump, a bad fuel pump relay or fuse, a bad crank or cam position sensor, a bad coil or igniter or even leaking ECU caps, as well as other things I have not listed.
this would be a great time to invest in the real factory service manual set, which has procedures for determining where the problem lies
otherwise, please go here and follow the simple procedure and download the OBD-I codes so we can better assist you - just because there is no check engine light, doesn't mean there are no stored codes!
many things can cause this type of problem, a bad fuel pump, a bad fuel pump relay or fuse, a bad crank or cam position sensor, a bad coil or igniter or even leaking ECU caps, as well as other things I have not listed.
this would be a great time to invest in the real factory service manual set, which has procedures for determining where the problem lies
Last edited by LScowboyLS; 03-10-13 at 03:39 AM.
03-10-13, 05:29 PM
#12
Lead Lap
Thread Starter
I have dealt with battery and alternator issues in the past. I'm sure that is not the problem. Checked out the fuel filter, plugs, plug wires, and caps. Found a vacuum hose that came loose and fixed that. Also used some injector cleaner as well.
After trying to trouble shoot this for a few hours, when I turn the car on it will idle at 600-650rpm and the next time it wants to idle at 1,500rpm. The stuttering is still there and seems intermittent to some degree. Sometimes when the car is turned on it will sputter a lot and the next time very little or not at all at idle, but will when driving. Also seems to jerk very hard when put into gear sometimes. Every time I turn the AC on it will die quickly.
I am now leaning towards thinking this is leaking ECU caps.
Thanks for the links LScowboy.
After trying to trouble shoot this for a few hours, when I turn the car on it will idle at 600-650rpm and the next time it wants to idle at 1,500rpm. The stuttering is still there and seems intermittent to some degree. Sometimes when the car is turned on it will sputter a lot and the next time very little or not at all at idle, but will when driving. Also seems to jerk very hard when put into gear sometimes. Every time I turn the AC on it will die quickly.
I am now leaning towards thinking this is leaking ECU caps.
Thanks for the links LScowboy.
03-10-13, 08:10 PM
#14
Lead Lap
Thread Starter
I remember a friend of mine had his LS do a very similar thing out of nowhere like mine. That also turned out to be the ECU.
Also blocked of the ACV in this process
Could a bad ECU cause the car to shift hard into drive or reverse?
Last edited by dc893; 03-10-13 at 08:15 PM.
03-10-13, 08:53 PM
#15
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My Cressida also had a bad hesitation issue. It felt like the car wasn't getting enough fuel. It would also run worse when the engine was warm or cold, can't remember which.
It turned out to be a dirty mass air flow sensor. Ran perfectly fine after it was cleaned. Might want to check that as well. Good luck!
It turned out to be a dirty mass air flow sensor. Ran perfectly fine after it was cleaned. Might want to check that as well. Good luck!