Gs300 Performance Degradation @ Pickup

95GS300 · May 6, 2008

Guys! I am a newbie, drive GS300 95 for a couple of years and simply in love with this beast.... The engine sounds fine at idle speed no missfiring, no viberation... etcthe problem recently happened was the car wont pickup as normal once stopped, takes good 50 sec to cross 100km then gradually goes normal? the Engine Mgmt Light is on.... The engine idle speed is at around 500~600RPM without AC and goes down at 200 if in D mode but idle. I tried resetting the ECU, the pick up returned for few min but then again the Engine Mgmt light came on.. and the performance dropped way below! Any ideas or suggestions? are wellcomed....? could it be due to Spark Plugs or Throttle Assembly wiring?? or any sensor? I couldnt find a mechanic with Code reader here in this part of the world.. (United Arab Emirates)..Please help!!

terry moore · May 6, 2008

Guys! I am a newbie, drive GS300 95 for a couple of years and simply in love with this beast.... The engine sounds fine at idle speed no missfiring, no viberation... etcthe problem recently happened was the car wont pickup as normal once stopped, takes good 50 sec to cross 100km then gradually goes normal? the Engine Mgmt Light is on.... The engine idle speed is at around 500~600RPM without AC and goes down at 200 if in D mode but idle. I tried resetting the ECU, the pick up returned for few min but then again the Engine Mgmt light came on.. and the performance dropped way below! Any ideas or suggestions? are wellcomed....? could it be due to Spark Plugs or Throttle Assembly wiring?? or any sensor? I couldnt find a mechanic with Code reader here in this part of the world.. (United Arab Emirates)..Please help!!

Hi,hope i can help,u can read the codes by using a wire, but u need 2 people,1 to control and check the engine warning light,and the other to bridge TE1 and E1 ON Your diagnostic socket,The CHECK ENGINE warning lamp will now flash a steady on/off ,turn on the ignition but do not start the engine.then bridge terminals TE1 AND E1. if there are no faults stored [0-0] CODE,the lamp will flash 0.25 sec apart,if there are any faults stored they will be indicated by two groups of flashes for each fault code,the first group of flashes signifies the first digit[1-5] OF the fault code and consists of flashes 0,5 seconds in duration.A pause of 1,5 seconds separates the two groups of flashes.the second group of flashes indicate the second digit[1-6] OF THE FAULT CODES and follows the format of the first group.if more codes have been recorded,ther will be a pause of 2,5 seconds between codes.when all fault codes have been displayed,there will be a 4,5 second pause before they are repeated.there are the codes u will need;1-1 ECU power supply;1-2 RPM signal;1-3 RPM signal-over 1000rpm;1-4 Ignition signal;2-1 Lambda sensor;2-2 Coolant temperature sensor;2-4 Air temterature sensor;2-5 Weak mixture;2-6 Rich mixture;3-1 Air flow sensor;4-1Throttle switch;4-2 speed sensor;4-3 starter signal;5-1 switch signal;5-2 knock sensor;5-3 knock control ECU;HOPR THIS HELPS U B) All the best

TigerFish · May 6, 2008

Hi,hope i can help,u can read the codes by using a wire, but u need 2 people,1 to control and check the engine warning light,and the other to bridge TE1 and E1 ON Your diagnostic socket,

Terry, Can this be done via the socket in the drivers foot well ( the one in this thread clicky ) and do you know if there is a plug available from Lexus to fit it?

terry moore · May 6, 2008

Hi,hope i can help,u can read the codes by using a wire, but u need 2 people,1 to control and check the engine warning light,and the other to bridge TE1 and E1 ON Your diagnostic socket,

Terry, Can this be done via the socket in the drivers foot well ( the one in this thread clicky ) and do you know if there is a plug available from Lexus to fit it?

Hi, yes it can be done ,but u need a USB SOCKET which plugs into any labtop,and u need the software.that read into your ECU.i have not done a GS But have done a SUPRA which is under the HAND BRAKE cover B) I dont think LEXUS will sell or lend this plug lead,co'z that what they use.this is y most people have to take there cars to a main dealer.i've tryed in the US,and could not get one,and now come end of the year,i'm going to JAPAN ,hoping to get one out there.u can get the software in the US, but that's not a problem B) .The plug in the foot well,u can play with alot ;IE the FUEL SYSTEM etc.

terry moore · May 7, 2008

Guys! I am a newbie, drive GS300 95 for a couple of years and simply in love with this beast.... The engine sounds fine at idle speed no missfiring, no viberation... etcthe problem recently happened was the car wont pickup as normal once stopped, takes good 50 sec to cross 100km then gradually goes normal? the Engine Mgmt Light is on.... The engine idle speed is at around 500~600RPM without AC and goes down at 200 if in D mode but idle. I tried resetting the ECU, the pick up returned for few min but then again the Engine Mgmt light came on.. and the performance dropped way below! Any ideas or suggestions? are wellcomed....? could it be due to Spark Plugs or Throttle Assembly wiring?? or any sensor? I couldnt find a mechanic with Code reader here in this part of the world.. (United Arab Emirates)..Please help!!

Hi, just found some old notes in my work shop, and should help u.For models fitted with Toyota TCCS fuel systems;FAULT;Hesistation/poor acceleration;COMPONENT CHECK SEQUENCE;1. signal from self-diagnosis;2.air intake and vacuum systems for leaks; 3.injector valves;4.throttle valve/sticking/position/linkage/dashpot;5.air control valve;6.auxiliary air valve;7.fuel pressure/delivery rate/regulator;8.injection system conections/wiring/relays B)

95GS300 · May 8, 2008

Guys! I am a newbie, drive GS300 95 for a couple of years and simply in love with this beast.... The engine sounds fine at idle speed no missfiring, no viberation... etcthe problem recently happened was the car wont pickup as normal once stopped, takes good 50 sec to cross 100km then gradually goes normal? the Engine Mgmt Light is on.... The engine idle speed is at around 500~600RPM without AC and goes down at 200 if in D mode but idle. I tried resetting the ECU, the pick up returned for few min but then again the Engine Mgmt light came on.. and the performance dropped way below! Any ideas or suggestions? are wellcomed....? could it be due to Spark Plugs or Throttle Assembly wiring?? or any sensor? I couldnt find a mechanic with Code reader here in this part of the world.. (United Arab Emirates)..Please help!!
Hi, just found some old notes in my work shop, and should help u.For models fitted with Toyota TCCS fuel systems;FAULT;Hesistation/poor acceleration;COMPONENT CHECK SEQUENCE;1. signal from self-diagnosis;2.air intake and vacuum systems for leaks; 3.injector valves;4.throttle valve/sticking/position/linkage/dashpot;5.air control valve;6.auxiliary air valve;7.fuel pressure/delivery rate/regulator;8.injection system conections/wiring/relays B)

Phew!! that was awesome .... rich contents here... I dont know how to thank you but really it was great to receive the replies.... just to be on safe side before asking the mechanic to have a look into these potential problems areas, if its possible to get the clarification that the Spark Plugs, type of Fuel (I use 91, instead of 95) or Gear Box / Tranny? has got nothing to do / less to do with the power accellaration / hesitation, sluggish response?

Also, on a quick note, if the 'N' Idle speed is around 500 & 'D' around 200, would that be one of possible route causes of Performance degradation? I find it very sluggish and it takes ages to cross 60km, the responsivness is really bad. However, once it crosses the 100km, the response becomes gradually better but only during the higher speeds.... Any idea? Thanks in Advance! I get the EML after crossing 1000RPM, and use 91 type fuel!

your answer is really appreciated.

Noel · May 8, 2008

just a thought, but as you live in Dubai... how often is the air filter changed?

does the GS300 have a MAF sensor? kinda sounds like it's not getting enough air or thinks it's not....and this would also effect the fueling...

terry moore · May 8, 2008

Guys! I am a newbie, drive GS300 95 for a couple of years and simply in love with this beast.... The engine sounds fine at idle speed no missfiring, no viberation... etcthe problem recently happened was the car wont pickup as normal once stopped, takes good 50 sec to cross 100km then gradually goes normal? the Engine Mgmt Light is on.... The engine idle speed is at around 500~600RPM without AC and goes down at 200 if in D mode but idle. I tried resetting the ECU, the pick up returned for few min but then again the Engine Mgmt light came on.. and the performance dropped way below! Any ideas or suggestions? are wellcomed....? could it be due to Spark Plugs or Throttle Assembly wiring?? or any sensor? I couldnt find a mechanic with Code reader here in this part of the world.. (United Arab Emirates)..Please help!!
Hi, just found some old notes in my work shop, and should help u.For models fitted with Toyota TCCS fuel systems;FAULT;Hesistation/poor acceleration;COMPONENT CHECK SEQUENCE;1. signal from self-diagnosis;2.air intake and vacuum systems for leaks; 3.injector valves;4.throttle valve/sticking/position/linkage/dashpot;5.air control valve;6.auxiliary air valve;7.fuel pressure/delivery rate/regulator;8.injection system conections/wiring/relays B)

Phew!! that was awesome .... rich contents here... I dont know how to thank you but really it was great to receive the replies.... just to be on safe side before asking the mechanic to have a look into these potential problems areas, if its possible to get the clarification that the Spark Plugs, type of Fuel (I use 91, instead of 95) or Gear Box / Tranny? has got nothing to do / less to do with the power accellaration / hesitation, sluggish response?

Also, on a quick note, if the 'N' Idle speed is around 500 & 'D' around 200, would that be one of possible route causes of Performance degradation? I find it very sluggish and it takes ages to cross 60km, the responsivness is really bad. However, once it crosses the 100km, the response becomes gradually better but only during the higher speeds.... Any idea? Thanks in Advance! I get the EML after crossing 1000RPM, and use 91 type fuel!

your answer is really appreciated.

Hi, just by reading this tells me,that set up of your throttle valve is incorrect.ATTENTION TO NUMER 4 AND 5.To set this up goes as follows;adjustment to throttle potentiometer, which is found on the throttle body.1 slacken throttle potentiometer retaining screws;2 insert 0,70mm feeler gauge blade between throttle stop bolt and lever;3 disconnect electic plug ,connect a ohmmeter between the 2 top electric pins which should be marked IDL AND E2; 4 Then turn throttle potentiometer clockwise until ohmmeter needle deflects; 5 then tighten retaining screws ,and it's done. B) all the best