I checked my fuses under the hood and found this blk/blue cable was not connected. Where does this cable need to be connected to and what purpose does it serve? Please let me know.

Thanks!

 

Did you ever find your problem....was it the fuel pump..?
I have a similar issue and would appreciate any help...thanks

Also, did you find out what the blue wire was for..?

 

Sorry for the delay in response, my work and school schedule has been tight. For my car starting issue I changed a few things (including changing my fuel pump) which I mentioned in my previous post but that did not resolve my issue. I then decided to change the PCV value, PCV garment and also the car ECU. Sense then the car has been driving smooth! Hope this helps you on your issue.....

PS: I bought the ECU from the junk yard, 2 of them just to ensure that 1 would work.

 

Is the car still running good..?
I already had my ECU rebuilt, run good for a month, and then came back. Do you think the PCV was the problem...?

 

i have a 1992 sc400 and i had pressure my motor becuase i had a oil leack so my mechanic told me to pressure watch my motor and now am having trouble it dont want to turn on, people tell me it might be spark plugs idk what it its pliss need help fasttttt plisss .:

 

i have a 1992 sc400 and i had pressure my motor becuase i had a oil leack so my mechanic told me to pressure watch my motor and now am having trouble it dont want to turn on, people tell me it might be spark plugs idk what it its pliss need help fasttttt plisss .: idk if it is the fuel pomp or the apark plugs need help

 

i have a 1992 sc400 and i had pressure my motor becuase i had a oil leack so my mechanic told me to pressure watch my motor and now am having trouble it dont want to turn on, people tell me it might be spark plugs idk what it its pliss need help fasttttt plisss .: idk if it is the fuel pomp or the apark plugs need help

 

i have a 1992 sc400 and i had pressure my motor becuase i had a oil leack so my mechanic told me to pressure watch my motor and now am having trouble it dont want to turn on, people tell me it might be spark plugs idk what it its pliss need help fasttttt plisss .: idk if it is the fuel pomp or the apark plugs need help

 

I am having the same issues. Letting the engine dry out may help minz still isnt starting either.

 

I have the same damn problem!! Car runs fine after I pull the relay? My RX-300 is golden (Knock on wood) but my wifes SC 400 has this issue. Hope all is well now!


I have a 1992 Lexus SC400 that is having issues starting so I went down the basic path (spark & fuel).

Note:
Previous owner never changed a thing except for getting an oil change. Also the car has sat sense October of 2010.

For spark:
I changed the battery, terminals, spark plugs, wires, distributor cap, distributor rotor and also the igniter. After I changed those parts the car started right up but then was when I notice that the car needed a new timing belt.

After a full timing belt job (water pump, tensor, timing belt etc) was changed the car started up and then I floored it and the car pealed tires and took off. After I turned the car off and then tried to turn the car on, the car just kept cranking and cranking. I thought it needed gas because the tank indicator stated that it was on “E”. Well I went and picked up some gas and placed in the tank. The car started up right afterwards so I made my way to the gas station to fill up. Funny thing was the gas pumped stopped at $30 which I know it takes my LS 400 $80 to fill up plus in addition the SC400 still said it was on “E” then it hit me that the gas indicator is broken. So I am at the gas station trying to startup the car and still nothing is happening. So I can my friend (mech) to look at the car and he is banging on the gas tank and nothing is happening. So then we popped the hood, removed the relay that was listed “EFI” and then re-inserted it. Afterwards the car started right up, no hesitation and I was on my way driving home but ended up racing a couple dudes on the way there. Once I got home I cut the car off and then tried to turn it back on and nothing…. The car would not start.

For fuel:
So far I have only changed the relay that was listed as “EFI” and also changed the gas tank indicator (some device that floats in the gas tank to measure the amount of gas in the tank) so now the dash states that the tank is full.

My question is what should I do next? Also, my friend stops over to use a jumper wire from +B to Fp in the diag box and we did not hear a thing, no fuel was flowing. So next we went to my 91 LS 400 and did the same, once we turned the key onto the on position the fuel starting flowing and flowing as if there was a water fall. We did the same thing again to the SC400 and yet again nothing. What should I replace next, the fuel pump? Also I’ve been trying to figure out if this car has a fuel pump relay and if so where do I find it? I search and came across a few posts that states it’s behind the driver seat under the floor or in the middle of the arm rest. Can someone please elaborate were the location is because I am quite confused lol.

I am sure my issue is with the fuel because the jumper wire tricked failed.

Sorry for the long post and thank you all for your help [/QUOTE]

 

Search for thread SC300 12V. FUEL MOD. talks about this issue.