1UZ Engine Shutting off when temperature rises to half
08-25-13, 11:55 AM
#16
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Years ago I had a 4th gen maxima with a bad ect sensor and it had the exact same symptoms you describe. I realize its a different animal entirely but it did exactly what you describe. It was like 15$ for the OEM last I checked on rockauto.
08-26-13, 04:48 PM
#17
The speedometer is not directly driven by the speed sensor. There is an ECU in between them. The signal from the speed sensor is sent to the ECU and processed. The ECU uses the processed signal to control the AT and others. The speedometer is just one of those others.
When the speed sensor is failed, there happens not only no movement of the speedometer but also many other problems such as no mileage increase, the AT doesn't shift properly, the gas mileage calculation fails and etc.
So there might be a possibility that the speed sensor is OK but the ECU is not fully OK.
When the speed sensor is failed, there happens not only no movement of the speedometer but also many other problems such as no mileage increase, the AT doesn't shift properly, the gas mileage calculation fails and etc.
So there might be a possibility that the speed sensor is OK but the ECU is not fully OK.
08-30-13, 04:03 AM
#18
Pole Position
Thread Starter
The speedometer is not directly driven by the speed sensor. There is an ECU in between them. The signal from the speed sensor is sent to the ECU and processed. The ECU uses the processed signal to control the AT and others. The speedometer is just one of those others.
When the speed sensor is failed, there happens not only no movement of the speedometer but also many other problems such as no mileage increase, the AT doesn't shift properly, the gas mileage calculation fails and etc.
So there might be a possibility that the speed sensor is OK but the ECU is not fully OK.
When the speed sensor is failed, there happens not only no movement of the speedometer but also many other problems such as no mileage increase, the AT doesn't shift properly, the gas mileage calculation fails and etc.
So there might be a possibility that the speed sensor is OK but the ECU is not fully OK.
08-30-13, 04:07 AM
#19
Pole Position
Thread Starter
you've just given me a little more hope.....This problem is so weird....No smoke at all, No codes...Luckily for this forum Im pointed in the right direction!
08-30-13, 11:59 AM
#20
Lexus Champion
The correct p/n is 89422-20010
08-30-13, 12:05 PM
#21
Lexus Champion
The speedometer is not directly driven by the speed sensor. There is an ECU in between them. The signal from the speed sensor is sent to the ECU and processed. The ECU uses the processed signal to control the AT and others. The speedometer is just one of those others.
When the speed sensor is failed, there happens not only no movement of the speedometer but also many other problems such as no mileage increase, the AT doesn't shift properly, the gas mileage calculation fails and etc.
So there might be a possibility that the speed sensor is OK but the ECU is not fully OK.
When the speed sensor is failed, there happens not only no movement of the speedometer but also many other problems such as no mileage increase, the AT doesn't shift properly, the gas mileage calculation fails and etc.
So there might be a possibility that the speed sensor is OK but the ECU is not fully OK.
but try the genuine Toyota temp sensor referenced above first.
09-02-13, 09:29 AM
#22
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Rock auto has maybe 8 options for the sensor atleast 3 of which have the exact same part number you present. Delphi, delco, beck, airtex all share te OEM number as alternates, it's likely the exact same part repackaged. Which is why I sad buy the "OEM"from rockauto. You want to waste money buying from Lexus be my guest but the parts are of the same origin reguard less of who sells them.
Last edited by PureDrifter; 09-02-13 at 03:09 PM. Reason: lose the attitude.
09-04-13, 11:36 AM
#23
Pole Position
Thread Starter
Ok this is getting somewhat tiresome and depressing.
I changed the Engine Coolant Temperature Sensor to the original toyota part p/n 89422-20010.
The problem still persists...
I changed the Engine Coolant Temperature Sensor to the original toyota part p/n 89422-20010.
The problem still persists...
09-06-13, 06:52 AM
#24
Pole Position
Thread Starter
I have taken back my 1996 Lexus LS400 from the mechanics to try solve this problem with the help of the more experienced Lexus owners on this forum.
I have been using the vehicle for the past couple days, and I have observed the following problems;
FIRST START on a morning (engine is cold) --- The vehicle works beastly perfect in traffic and on highway. No smoke, no rough idling. Normal Idle at 500 RPM
After 20 minutes (when the engine is warm) ----The vehicle begins to rough idle. No smoke.
------------------------------------------------------------When in traffic, it rough idles and the RPM drops below 500RPM and consequently cuts off. UNLESS while in traffic, I put the vehicle in Neutral and Accelerate\ REV till the Tachometer needle reaches at least the 2000RPM mark then I release the acceleration, only then the rough idle stops and idles normally again at 500RPM….and I work it like this “coasting” in traffic. However, if I drive in traffic accelerating under 2000RPM, the rough idle and shutting off would persist.
-------------------------------------------------------------When driving on highway (80 mph and more) which is above 2000 RPM on the Tachometer, the vehicle does not rough idle, it runs smooth. However, If I am driving slowly on the highway (approximately below the 2000RPM) the rough idle and jerking would persist.
My thoughts--- The mere fact that I am experiencing this problem when;
1) The Vehicle/Engine/Engine components are getting heated;
Leads me to believe that I can narrow down to either (A) Ignition coils (B) Fuel Pump
2) When heated, only runs smooth when I accelerate approximately above 2000RPM;
Leads me to further narrow down to (B) Fuel Pump
Your suggestions please. Furthermore, a Part number for this fuel pump would also be helpful.
I have been using the vehicle for the past couple days, and I have observed the following problems;
FIRST START on a morning (engine is cold) --- The vehicle works beastly perfect in traffic and on highway. No smoke, no rough idling. Normal Idle at 500 RPM
After 20 minutes (when the engine is warm) ----The vehicle begins to rough idle. No smoke.
------------------------------------------------------------When in traffic, it rough idles and the RPM drops below 500RPM and consequently cuts off. UNLESS while in traffic, I put the vehicle in Neutral and Accelerate\ REV till the Tachometer needle reaches at least the 2000RPM mark then I release the acceleration, only then the rough idle stops and idles normally again at 500RPM….and I work it like this “coasting” in traffic. However, if I drive in traffic accelerating under 2000RPM, the rough idle and shutting off would persist.
-------------------------------------------------------------When driving on highway (80 mph and more) which is above 2000 RPM on the Tachometer, the vehicle does not rough idle, it runs smooth. However, If I am driving slowly on the highway (approximately below the 2000RPM) the rough idle and jerking would persist.
My thoughts--- The mere fact that I am experiencing this problem when;
1) The Vehicle/Engine/Engine components are getting heated;
Leads me to believe that I can narrow down to either (A) Ignition coils (B) Fuel Pump
2) When heated, only runs smooth when I accelerate approximately above 2000RPM;
Leads me to further narrow down to (B) Fuel Pump
Your suggestions please. Furthermore, a Part number for this fuel pump would also be helpful.
09-06-13, 01:39 PM
#25
Lexus Champion
Matt - fuel pumps and coils are extremely rare to go out in a 96 LS400
I told ya what the extremely likely source of the problem is, back at the beginning of this thread, the ECU capacitors, this is very common and you have the symptoms!
why replace all kinds of other things first, rather than start with what has time and time again solved this issue for so many folks?
I told ya what the extremely likely source of the problem is, back at the beginning of this thread, the ECU capacitors, this is very common and you have the symptoms!
why replace all kinds of other things first, rather than start with what has time and time again solved this issue for so many folks?
09-07-13, 04:26 AM
#26
Pole Position
Thread Starter
Your informative thread on ECU Failing Capacitors was relayed to my electrician, and when asked, he told me that he changed the stated capacitors. As advised, I am doing the systematic approach..
09-07-13, 08:57 AM
#27
Lexus Champion
he didn't use the correct rare special type capacitors, because he didn't know any better and you hadn't ordered the ones I linked to, to supply to him - happens all of the time.
09-10-13, 04:57 AM
#28
Pole Position
Thread Starter
I will request a list of the capacitors to which he replaced. However, I am proceeding to change the fuel pump in my 96LS400....any advice or a link to where I can source a gasket for the fuel pump set plate would be appreciated.
So now you are changing the fuel pump? It's your car and money, but I would listen to the advice and look further into your ecu. It MUST be done with the correct caps, and is not an easy job.