jaxscuby

So recently when the car is cold, usually o'dark thirty when I am trying to go to work.
The car will turn over and not fire. This goes on for several minutes. it almost sounds like it fires and
want to idle but dies. Then after about what feels like 10 minutes of cranking the motor over it fires enough
to idle with the help of gas pedal. I have to modulate the gas pedal when it is trying to idle and slowly release
the gas pedal and it will find idle on its own.

with in the past 6 months the coils, wires, plugs and timing belt kit have been replaced.

I went to autozone yesterday to clean my IACV and MAF sensor. Checked the plugs and all were fouled out..black..rich.
replaced the spark plugs runs smooth, but the start up trouble still existing. And replaced temperature sensor.

So I think I have spark (see above ignition parts), fuel (the old spark plugs were black as coal) and air (I did not replace the IACV
but did "clean" it. Air filter is slightly dirty and not clogged.

the check engine light I had was for cam sensor 1. had this cel after timing kit when the wires were too close to serpent drive belt.
of course besides the misfires for the fouled spark plugs.

So I searched for previous threads and did not find anything closely related..what gives?

tia

Ben

timmy0tool

iTrader: (7)

how dirty was the IACV? if I remember correctly after cleaning it the car will need to relearn the idle position so it can adjust the valve appropriately.
https://www.clublexus.com/forums/per...acv-sc400.html

jaxscuby

there was some build up, but nothing the maf/throttle body cleaner couldn't take down.
and wiped it down with clean paper towel.

this might have been first lexus IACV, but a few before this and always straight forward.
and once the car did get started...I let is "learn" idle for the next 30 to 40 minutes

still enjoying my morning ritual of ~10 minutes of starting..
replacing IACV..

jaxscuby

spent my lunch hour at up-pull it yard getting a donor IACV.
so it will be an interesting afternoon.

YODAONE

Whether or not the proximate cause, if original, replace these components;

1.) Coolant temperature sensor....use OEM

2.) ECU capacitors

3.) Fuel filters use OEM

4.) Fuel pump.use OEM

5.) All negative cable/ground point fasteners MUST USE OEM.

6.) Fuel.pump resistor. Use OEM

7.) Replace all bladed fuses (tarnished =resistance) in engine compartment and footwell..buy from Digi-Key.

8.) Crank position sensor...

9.) Be sure you acquire wire harness side connector shells for each component you are replacing.

jaxscuby

Originally Posted by Banshee365
FWIW you're not troubleshooting. You're firing the parts cannon at it.

well currently it is my daily driver and can not afford to have down for more than a day.

jaxscuby

so when I tried yesterday afternoon the engine was still warm when I completed the swap of IACV.

and I tried it is morning and still having cold start issues. when i go to change the oil I'll check crank sensor.

I know its temperature dependent because once the engine gets warmed up the start up issue goes away.

jaxscuby

changed oil & filter this morning after fighting the car for ~10 mins.
dropped the crank sensor out of its location to find it partial covered
in oily dirt. I will go by the u-pull it yard to collect some trouble shooting
sensors..

jaxscuby

So I gad my daily ritual of trying to get the car to start.
but I checked relays and all fuses to day. And it did got fight
me for 10 minutes. it actually started on first try. but the early morning test
will verify if the relays and fuses solved the problem.

Yamae

I'd simply check the coolant temperature sensor measuring the resistance. It should be higher than 2K Ohms when cold.

jaxscuby

so i leaning toward the capacitors in the ecu. why? because nothing makes since.
I fought the car this morning to get to work and it gots its revenge this afternoon.
battery out of the car on charger as i type. positive cable terminal was loose upon inspection.

jaxscuby

hhmmm..something looks odd.
hhmm..part 2..something looks odd
oh really? date says 2 jul 2010

jaxscuby

remanufactured ecu on its way..should arrive wednesday..tomorrow..120 ecu..24 overnight..

jaxscuby

so my replacement got to apt around 1 pm..i got home before 2 pm.
got everything back in..

but still no joy. this sucks

Yamae

Sounds like you are not doing what you can do very quickly and easily.