I’ve been searching, but thought I might as well throw this up and see if anyone cares to provide input. My SC just all of the sudden one day last week decided to not want to start right up as it always has done. I had to press the gas pedal to get it to start. Did some internet searching and found a few hints on what it could be.

So far I have replaced the air filter (just because it really needed it mostly), fuel filter, cleaned the air idle control valve, and replaced the pcv valve. I thought it was fixed a couple times, but it’s not. It still doesn’t want to start correctly. Sometimes if I let it crank abnormally long it will fire up or else I have to hit the gas pedal. Seems better if I go back to start it up right after it has been running – like run into the store and come back out, etc. which makes me think it’s because the pressure is still in the gas lines, but I am clueless about this really.

So, I’m thinking fuel pump, but I would like to test it first before spending money on a pump if that’s not it. Autozone has a test kit that they loan out, but I don’t know what pressures I will be looking for and I’m not seeing it on here. Any input?

 

My advice is to pay a professional to diagnose it. Your just trowing your money away replacing parts thst are good. Just pay the $80 at a mom and pop shop to look at it, take it from there. Once you know the problem, you can fix it yourelf. You need to know how to check for fuel or spark. Could be your starter, alternator, fuel regulator, anything.

 

I've been trying to solve the same problem...

https://www.clublexus.com/forums/sc-...esitation.html

My spark plugs/wires and fuel filter needed replacing, but they didn't help with the start-up issue. I tried a replacement fuel pump and that seemed to help initially, but overall it's about the same. I've got a couple symptoms of a weak alternator, so I'll be checking on that. My guess is something to do with fuel pressure, though.

 

I appreciate the advice and I may do that, but an air filter, fuel filter, pcv valve, cleaning the air idle control valve on a 20 year old car with over 215k miles probably wasn’t just throwing money away. Those items all probably deserved to be addressed.

 

Try the fuel pump ecu bypass. It's easy and many times is the culprit.

 

I believe the culprit wound up being a vacuum hose that was left loose after a recent water pump replacement by a local garage (they did an otherwise great job).