Relex

Hi there,

I was hoping someone can help me with a starting/idling issue that I am having.
Really need some pointers

Each morning my Gs300 cranks over and over but dose not start until 5 or 6th attempt , when it dose it needs about 3 min to catch idle or it will shake slowly and die. Car runs great and has no check engine light or code but thats after you get it to turn on and keep your foot on the gas for 3 min at 2000 rpm. After 10 min of driving its like a new car, responsive and idles at 400 rpm in stop / go traffic, , I did experience "limp mode" only once right after I took off without waiting to warm up, but most throttle parts are oem brand new...

tough one , please help

List of new parts already on the car.

Parts from dealer
MAF sensor
Pedal Acceleration/throttle sensor ( new rev.)
Idle Control Motor
TPS
Oil control valve sensor
Cam Sensor
Bank 1 Oxygen Sensors Up and Down.
Coolant temp sensor
Intake gasket kit

Denso Parts
Fuel Pump
Fuel Pressure Regulator
Dampener
Fuel Filter
Strainer
All (in-tank) seals and gaskets


Aftermarket Parts
Starter -reman
Alternator-reman
Spark plugs (single tip )
Wires

I also:
cleaned throttle body and added new gasket, put on a spare throttle body ,also same problem.
Added new battery and terminal connectors, No vacuum leaks or loose or cut wires,

about the only things still original that I haven't changed yet are coil paks and crank sensor.

Thank you for any input.

offbad

iTrader: (5)

if i'm not mistaken... the 98 uses double ground spark plugs OEM right?

Relex

thank you,
yes, you are right, just don't think that would cause such serious issues ,
spark plugs are only 6 months old...

MikeFoxx

iTrader: (8)

^^^^^ Why Not?

and

https://www.clublexus.com/forums/gs-...ugs-wires.html

Relex

thanks Mike

MikeFoxx

iTrader: (8)

i would honestly start there Relex simply because you know that part is wrong. Good luck

wbmx1981

I'd start with the right plugs.

Relex

thank you, I am getting Denso PK16TR11 tomorrow ill put them in and see what happens

Relex

ok, changed all spark plugs ,boots and wires( all denso )
and it still has starting problems and needs about 2 min to catch idle...

almost feels like there is no fuel pressure during start up, car shakes a bit at 1000 rpm. (first 2 min)

I noticed that If I move the TPS it starts right up but then later still has same issue... this is the only indication so far that makes me think that I finally isolated the problem..

dose anyone know the ICV /ICM Toyota part # ? or where I can find gs300 fuel diagram...
don't know what it could be....

Relex

I now noticed a low fuel light , comes on for a sec when I am trying to crank the car.
when I play with the TPS is helps but for next start up only..... any ideas?

chrcrou26

The next time you start it loosen the two screws on the tps sensor and tap it if this affects you idle your sensor might be going bad also I saw it starts fine when you move it so I would check that it's clean inside and is firmly attached as well.....could also have a fuel pump issue or hole letting air in you fuel lines....either way if this test works your sensor needs replaced anyway and may be your only problem 0 throttle is the same as no fuel flow so the gas light may be a false indicator

Relex

thanks, i am getting a new toyota tps tomorrow , ill see what happens,
i wonder why its only happening during start up, car runs fine as soon as I can get it to drive,

the fact that i can alter the way its starts with the tps adjustments and I sometimes experience limp mode during first minute of driving , can I almost certainly rule out fuel system issues?

chrcrou26

I would say yes....that's what you get with drive by wire systems.....Our throttle cable is only a fail safe so when you get that limp mode is because the sensor is malfunctioning....and also unfortunately the throttle control system is a closed circuit so if your tps acts the whole throttle body essentially shuts down so that last smidge at the end of a mashed pedal is all we got.....One I'm sure many members wishes lexus rethought lol

Relex

thanks , and sorry, looks like my last post had some copy txt issues... odd

anyway.... the TPS and the pull by wire ( accelerator assy sensor ) are new Toyota parts.... can it be the ICM?

the throttle body is all nice and clean and almost all sensors are new.... hmm...

chrcrou26

Naw if it was the icm malfunctioning you would have completely different symptoms....wouldn't start at all most likely and if it did you have spark issues everywhere So even if it's new stuff the drive by wire is just a touchy Could just have a faulty sensor again even if you replaced it