Alright guys I’m at a lost I replaced the immobilizer module,car has new plugs, new pcv valve, new fuel pressure sensor and the gas is good but yet I still get no fire up it continuously cranks I spray brake cleaner into the air box( I know how dangerous it is I just had no starter fluid) and it fires up and dies immediately both my cats are hollowed out so it’s not clogged cats but I’m just lost at this point

 

I believe on the Lexus the immobilizer controls the fuel pump. If it's not happy then the fuel pump won't work. Did you do the reset procedure and check it with Techstream?

 

I’m getting fuel the pump is pumping from what I know unless I’m wrong the procedure was to ground out pins 4 and 13 on the obd2

 

Well if fuel was making it to the combustion chamber it should run just like when you sprayed into the intake. When you first push the start button do you hear the high pressure fuel pump buzzing?

 

yes I can hear it I even pulled the hose off after the pump to see if fuel was coming out and fuel was coming out

 

When was the last time it ran and why was the immobilizer ecu replaced? I'd guess something in that realm is amiss.

IS-350 or 250? I'd guess if Techstream were connected, you'd have a better idea of why its not staying running.

What does the security light do when placed in accessory mode?

 

Its an is250 and last time it ran fine nothing to bad to it just had a p420 code and would run a little rough. The owner before me replaced the plugs and intake gaskets.I parked the vehicle and it was raining pretty rough and hard and it was somewhat down a incline down hill. The next day I go to start it just cranks and doesn’t fire up. So my thought process went to my cats finally clogged out so I replaced the 02 sensors installed spacer and hollowed the cats out. I go to start it no luck same continuous crank no fire up so I see that there is an issue of the fuel pressure sensor being messed up and people don’t notice during tune ups so I go and replace it. No luck same results I pull a fuel sample and fuel comes clean I pull the fuel line after the high pressure pump to see if I’m getting fuel to the injectors and I am. So I go to check all my fuses and they all check out fine. So for a week I’m stumped and my budy at work (I work at a Kia shop) let me borrow his maxum 4.0 matco scanner and saw the only dtc present that would not clear was my a fault for my immobilizer b2799 so I go ahead and order the module. I just got the module yesterday and replaced it and still no luck
Also idk if it would hint or clue something to you but the tpms module also somehow shorted out and my tpms light is on


the security light turns on when in accessory mode and the color on the push start changes from orange to green

and like I had mentioned with some brake cleaner I can get it to fire up but dies immediately as soon as it fires up

 

I do not have first hand experience to say it is 100% your problem but that security light needs to be off. Im on mobile and hate doing seaches but I doubt the original module was bad. What is more likely is the weak cold start injector in the throttle body kept it from running. Then with repeated cranking the the battery ran low, and data transmission to/from the various computers was compromised and a code was set with the immobilizer placing you where you are now.

I believe that code needs cleared first before trying to start again. That said, do some searching on handshaking the ECU and immobilizer circuit. I think that is the second step and then, apply your starter fluid (brake clean??? -ouch-) and try and start it.

Also search on engine ECU replacement for a 30 minute process that fixes these issues. You might include IS-F forum and yt.

 

Someone help this dude out!