chungmeow

Hello members!

I've searched this forum for possible solutions in the past month however, I don't believe I figured it out yet. The weather is warmer in Chicago and I thought I'd try to fix it myself. Brief intro - purchased this car October 2014 @ 125K miles and prolonged cranking had been an issue from the start.

What I've done so far:
- Replaced battery
- Replaced starter motor
- Replaced air filter
- Sprayed injector cleaner
- (not relevant - added aux cord using 4PDT switch implementation)

Symptoms:
- Prolonged cranking for about 3-4 seconds
- When the fuel tank is full, the car starts quickly whether if its warm or cold outside
- Even when the fuel tank is full or nearly full, at times, it continues to struggle randomly
- The prolonged cranking is more prevalent when 1/4 tank of fuel is remaining
- At times, prolonged cranking caused low idling however, car never stalled.
- When bitter cold outside, initially when the car starts, the engine hums loudly until warm (which i dont think is relevant...)

Thoughts:
- I've read that due to the required power needed to fuel the engine, a weaker battery would be the cause of prolonged cranking
- Also heard from a retired lexus mechanic that it was some temperature sensor that detected the temp of the fuel which would directly affect the cranking (He told me it was something that frequently happened back in the day..)
- Possible fuel pump issue
- debri in idle air control
- fuel filter?
- some people decided to just deal with it

Any suggestions? and thanks..

MikeFig82

iTrader: (13)

I would look at checking your fuel filter first. If your car has 125k on its possible it's still running on the OEM. I've changed mine out before and it was pretty dirty. like the one on the link below.

https://www.clublexus.com/forums/gs-second-generation/483026-cross-section-of-gs-fuel-filter.html