In the recent couple of weeks my 01 GS430 developed a problem starting up. I need to crank it for a long time before it finally fires up, and sometimes it will only fire up on the second try. After it starts, it seems to lag a before reaching around 2500 RPMs, and then takes off like a bat.
Replaced spark plugs over the weekend with no result. Everything in the car is maintained well, new fuel filter, timing belt/water pump were recently replaced,
throttle body cleaned, new o2 sensors, new MAF, etc.
What can it be? There are no codes whatsoever. Could it be the fuel pump? And if its the fuel pump, would it be likely for the car to start hard but run well at higher RPM range?
This ad is not displayed to registered members. Register your free account today and become a member on Club Lexus!
Long cranking is a sign of a bad fuel pump.. Was your old fuel pump bad? They seldom need replacing unless you encounter the symptoms you mentioned in your original post. I am still on my original fuel pump with 106k on the clock.
The North East Forum is back Tri State Area!! Join us!
I'd say pump like mentioned. When you turn the key, pressure builds up, but the pump appears to be losing pressure causing it to crank and crank. Not sure if our cars have a fuel pressure regulator, but if so, that might also be the issue.
So now I pretty much know for sure the fuel pressure is too low. Theres a fuel hose going up to the engine, and compared to the same hose in my friends GS430, it feels 50% less pressurised, both when the car is on or off. I wonder now if thats the fuel pump or leaky injectors.
Well w/mine, I found the previous owner replaced the vac hose on the PCV valve with plain rubber. Over time, line was collapsing from the suction. I swapped out with vac line; starting is back to normal.