Queend1026

Hi I’m new to this website but I’m here to see if anyone may be able to help me figure out what’s wrong with my 2001 Lexus GS 300, it has 200,000 miles and it stopped running 3 weeks ago. I thought it was the fuel pump because it would idle real low when I’m sitting parked or in a drive thru and sometimes the car would Idle so low that it would turn off but it would always start again . The day it broke down I felt it in the pedal that the car was Loosing power because when I’d press the gas pedal at a light the car would feel like it doesn’t want to go like a putter sound in the begin . Then it just trunned off on me as I was driving down the rode. Once I got it towed home I changed the fuel pump but the car still didn’t start ... then I replaced the efi fuse and BOOM my car started. I let it warm up and after about 5 mins the car turned off ... then I tried to start it again and it won’t start . It sounds like it wants too but it won’t . So then I bought starting fluid and sprayed it as I started the car and the car started . But then it turned right back off . I feel like I have a fuel problem but I don’t know where to start from here . Maybe just dirty fuel injectors?

KyleH

iTrader: (1)

Start with making sure you're getting power to the fuel pump. Pry the back of the plug cover off and you'll see the wires through the back of the plug. Or you can pull the plug off the connector and meter it from the other side. It will probably show low voltage like 7 volts or so when the car is just idling. Reason it you don't get full voltage until the ECU triggers it based on RPM and / or throttle position. But if you're seeing 7 volts, then the pump *should* be running. At this point, you need to validate that the pump is functioning. Pull the seal and make sure you can hear/see the pump running, unless you can more easily validate fuel pressure at the rail somehow.

I've attached a picture of the back of a fuel pump plug wire. It's the larger blue wire with the red stripe that should be the positive and the larger blue with yellow (I think) is the ground. By measuring these, you should be able to validate if power is making to your pump.


Report back on progress.

Tuanville

Is the check engine light on?

Queend1026

no the check engine light isn’t on

Queend1026

great news I got my car started I replaced the fuel pump again and it worked but now the car shakes really bad I kinda don’t wanna drive it

KyleH

iTrader: (1)

Well, I wouldn't drive it either if it's shaking. The engine isn't running well. Look for codes at this point, as I would expect if it's misfires, the ECU would be detecting and reporting this. Try to get a code scanner and look for codes. You can throw some fresh spark plugs at it and see if that clears it up if they haven't been replaced since you've owned it, they're probably due anyway. Again - so many variables, we can only guess if you don't have the codes pulled and can't provide some more information about the symptoms.

Queend1026

I was thinking of replacing the spark plugs too since I have never done that since I’ve have the car (august 2020) . I’m gonna do that ASAP , also the codes where p0174 p0171 and ive already replaced the mass air flow sensor and the o2 sensor on the catalytic converter . Any thing you might think
it is?

KyleH

iTrader: (1)

Google those codes with Lexus / Lexus GS and you'll come up with a lot of articles. Basically indicating your engine is running lean. That is not surprising given you said it was not running well. Could be a massive air leak between the MAF and combustion chamber, could be a faulty fuel injector or plugged fuel filter preventing the correct amount of fuel from reaching the chamber. No way to know what if is, for certain but start with the cheap stuff first - such as ensuring you don't have any loose hoses, clamps, etc. that are allowing unmetered air to enter the engine after the MAF. If you feel quite confident your MAF is good and you don't have air leaks, time to start looking at blockages or faults on the fuel side.