need some advice for a 1990 lexus ls400 supercharged stored for 12 years

ifeelsooblue

New Member
will crank and start for half a second then shut off. my original post and updates of what i've done so far is on clublexus.com (please go to the link below for extensive details of what i've done so far).


i am getting spark and there is no issue with MAF.. i am thinking is a fuel issue but older model lexus its hard to tap into the lines to check fuel pressure working on a mod to test pressure after fuel filter, inlet to fuel rail. i am actually thinking about taking off the cartech FMU off temporary because sitting so long i think diaphrame and springs inside the FMU are stuck.. maybe its fuel pressure regulator thing (stock one on the car) but it doesn't leak gas when i take vac hose off.. now i am thinking about pulling the entire fuel rail off and check each injectors (but i am not sure if thats the problem). when i spray starting fluid down the intake it does start for about 1-2 seconds then dies.

changed valve cover gasket, new plugs, wires, engine oil, coolant, (planning to change out the rotor and distributor this weekend too. tested the OHM on injectors shows 13.9-13.7 on all 8 injectors but maybe clogged due to being in storage for 12 years. my biggest mistake is not draining the fuel so in the beginning i had to deal with crystalized fuel tank.. cleaned it all out and changed fuel pump (replaced with walbro 255) anyway since it seems like more folks are modifying V8s here so i thought to get some advice here. wondering if there is anyone out there that is from the LA CALI area that might be able to help. ironically this supercharger kit was purcahsed from Lextreme himself. what i put on my car was his prototype.
 

hypronet

Member
Hi, have you change the fuel in this cause fuel separates over time an goes off also can leave a gum in pump, filter, line an injectors so first thing I would do is flush the fuel system. Pulling out the plug an cranking it over would allow you to check all plugs are firing correctly an no harm doing an oil change an new filter.
 

ifeelsooblue

New Member
Hi, have you change the fuel in this cause fuel separates over time an goes off also can leave a gum in pump, filter, line an injectors so first thing I would do is flush the fuel system. Pulling out the plug an cranking it over would allow you to check all plugs are firing correctly an no harm doing an oil change an new filter.
ive changed the fuel filter, injectors and cleaned the fuel rails and got rid of all the old fuel. put about 10 gallon of 93 gas with 10 OZ of seafoam hoping it will clear the lines from the tank to the rails (everything in between). i have no idea how to flush the lines should it be clogged somewhere between after the fuel filter to the fuel rail. i changed all the plugs, wires, caps and rotors, fresh engine oil coolant flush. will try to fire it up in a few days or so after i put in the new water temp thermostat.... right now i am missing this part from lexus...
 

ifeelsooblue

New Member
Another supercharged uz which had been sitting for ages. Rust in injectors
interesting video. i did exactly what he did and pulled out the fuel rails and replaced all new injectors. i am trying to figure out how much fuel pressure i have after fuel filter but its not really easy to tap in to considering there is no shredder valve. also the fuel pump does not prime on the 1990 ls400 until you actually crank to try to start the car.. i replaced the fuel pump as well to a walbro 255.
 

gloverman

Well-Known Member
Easy way to check fuel flow is from return line. Activate fuel pump using stock fuel relay bypass and measure return. Easy as.
 
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