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Still having more than one is nice in case one either gives up the ghost or won't communicate with a particular vehicle.
Let us know how you go with sensor readings and codes.
I went to plug in the new reader and found a wireless reader already plugged in to the socket. Then remembered that several years ago I got the wireless one and so I found the old phone I had at that time and the software was still on it. So now I can use the old phone, not for a phone, but as a diagnostic tool for the permanently installed wifi reader in the LS430. I will just keep the old phone in the glove box.
SOoooo, what could cause no start that does not write a code????? I think a fuel pump failure would write a code. Spark failure would write a code.
Any ideas??
Fuel pump failure most certainly would not trip a code. I'm not sure if our fuel rails have a test port or a valve where you can measure pressure but pump failure, while rare, is a possibility. As others have mentioned, a sensor can cause a no-start condition, but that should trigger a CEL.
There are no easy fuel pressure tests in the 3uz. There is no built in manual fuel pressure port. Nor is there a fuel pressure sensor. All the connections are threaded or banjo joints. Which means you need threaded t peice + adaptors where the fuel line enters the engine bay in order to get a proper reading.
Having said that - There is a kind of tell-tale of fuel pressure being present or not.
Which involves the FPD (Fuel pulsation dampeners). These are located at the back of the fuel rails on each bank (lift the plastic engine cover). They could either be bright finish (as per pic,) or painted black.
When fuel pressure is present (ie ignition on engine off) the small centre philips screw heads are slightly raised (perhaps 1 or 2mm) almost appearing visibly as though someone hadn't tightened it quite properly. It is subtle.
You can press directly down on the screw head with fingers, if it moves down, then you have fuel pressure.
If it unable to move down (as shown in the picture above, fully down position), the is no pressure pushing the screws up.
Check the fuel pump relay. Pull it out and give it a tap and spray with contact cleaner.
Also does the check engine light come on when you turn the key to on but not start it.
It should illuminate prior to stating the car.
Yep, looks like its the fuel pump. Sprayed starter fluid into the intake and it started instantly. Checked the relay and there is voltage to the pump. Mechanic is looking for the pump as I write this. Looks like it will be a cheap fix. Now I am looking to maybe trade it in on an SC430.....LOL
Certain electrical components can prevent the engine from starting/running. For example, if the crank or cam sensor is not present or inactive (no signal whatsoever) the ECU will not allow the engine to fire until this information is received. This thread could point you in a useful direction- https://www.clublexus.com/forums/ls-...n-t-start.html
Now you have me looking for an SC 430. I dont need that......LOL
I just replaced my fuel filter and pump on a 2002. It was easy. Take out the backseat simply by pulling up on it. Its pop locked in 4 places.. 2 in the middle and one in each side(between legs of passenger on either side).
Pump replacement is fun.. but a little gassy. Need a new gasket, pump, filter.. just need a 3/16? Socket to remove screws under the initial cover under the driver side rear seat... Youtube it
After pump replacement and filter you'll have much better performance 💪
Separate the plastic top from bottom with a flathead. This is a plastic on plastic snap together deal. Take your time, its fun.. Open the first cover to reveal the screws that will only come out with a socket. Don't forget to open the gas cap to release pressure.. though that may not help. Have towels ready.. If you've worked on cars then this will be a breeze.
The relay is sending b+ to pump but pump is not running. I noticed Denso had 1 year warranty and Bosch had lifetime warranty, but since the original lasted 16 years & its an easy job, I decided warranty length wasnt worth worrying about....LOL
I have had same experience on 2004 LS430 with 44,000 miles on it. Cleaned MAF and throttle body with appropriate CRC cleaners. Ran great for several weeks then stalled. Restarted again the next day. Ordered fuel filter (canister) and Denso PN 950-0107, fuel pump, it is too long and will not allow fuel canister assembly to snap shut. Waiting for receipt of Denso PN 950-0003 fuel pump, which appears shorter in length and was previous model. There is a decent YouTube video showing fuel pump replacement process. Should be able to complete assembly tomorrow, but won’t have confidence it is fixed until I drive it for awhile. The car otherwise has not had any failures in 10 years.
The final nail in the coffin.
I got the fuel pump replaced, the relay replaced (it was welded shut causing the pump failure), front rotors and pads replaced, oil and filter changed (synthetic) for a total bill, parts and labor of $950. I rent his garage to him and he owed me $800 so it only cost me $150 bucks. Oh, and he did the work at my house.
The car runs great, no longer shakes on hard breaking and is once again so quiet I have to look at the tach to see if its running.
Good for another 90K...I hope.
03-02-21, 05:02 PM
