90 Lexus LS 400 ISCV

[redcarrara]

wHAT tells the ISCV to open and close? Is it the engine CPU or some other sensor? Mine seems to be functioning but not when it should. The idle will drop off for no reason at all.

 

[Edwin_S]

That would be the engine ECU yes..

 

[redcarrara]

Ls 400 Engine Idle

My engine idle was bouncing all over the place, and the car was stalling for no reason. The car had been to 4 mechanics including the dealer. No codes read and the check engine light never came on unless it stalled and the entire dash lights up. I played with the ISCV, unplugged it, sprayed cleaner in the vacume line, nothing happened. I just replaced the engine CPU and the car runs perfectly. Thanks for everyone's help!

 

[Lextreme II]

You might want to check your full pressure and AFR. If the system is either lean or rich will trigger the ECU to compensate via the idle by alternating the ISCV. I would definately check on the pressure regular and or fuel pump too. Just to see if the system is holding fuel pressure.

 

[redcarrara]

lexus bouncing idle

I tried to replace the fuel filter and it is rusted in place. Any ideas about cutting the lines on both sides and splicing in a new fuel filter? Also in replacing the engine CPU below the glove box, I removed one lower panel and then took out the lower bolts for the next panel that holds the CPU but cannot figure out how it is attached on the top just below the glove box hinge. To get back to the idle it works fine now, should I check the pressure in the fuel line to check the fuel pressure valve? I have heard that this could be a fuel pump problem, but I thought I would start by changing the filter which is giving me a problem. Life is a circle.

 

[Lextreme II]

http://lextreme.com/fuelfilter.html