BrittonJ85

Good afternoon,

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

1jzchris

Sounds like when your fuel pump gets hot it cuts out unitl it cools down. Change the fuel pump and Bypass the fuel pump ECU...........search for full instructions on how to do it.

BrittonJ85

Thank you for your response. Do you think a Walbro 255 LPH is ok to use

http://cgi.ebay.com/ebaymotors/92-00...#ht_4363wt_762

Thank!

BrittonJ85

Sorry for posting this but I did not find a answer on the forums to my question. I was wondering, do I need to drain the gas out the tank before changing the fuel pump? Currently the tank is on "F". Please let me know.

Thanks!

1jzchris

No you dont NEED to drain it.........i changed mine with a half tank of gas.

gunyvw

change the fuel filter...

xspsi6

iTrader: (31)

Do not change it on full!!

1jzchris

why not...........................?

xspsi6

iTrader: (31)

That is NOT a walbro 255 and is a chinese knockoff so I would say stay far away that garbage!

Also do yourself a favor and do not change your tank on full unless you like to have fuel drenched interior

BrittonJ85

Just a quick update:

So I changed the fuel pump and Bypass the fuel pump ECU (using the Fuel 12v fix) in which the car started "that morning" but after I drove the car for about "20 miles" then parked and turn off the car, it would not start up again. It just kept cranking over as if it wanted to but was not receiving any fuel. So I waited the next morning and then the car would start.

What else should I do? Also I notice the the EFI relay was a bit too hot when I touched it. Is that common? And also say for instance that the car would not start, I could jump start it by doing the following:

1 - Put the key in the ignition and turned it onto the on position.
2 - Remove the EFI relay
3 - Re-connect the EFI relay (once connected you will hear the fuel pass threw the fuel rails
4 - Start up the car

I can't figure out why that would correct the issue.

Also I tried 4 different fuel pump ecu from other SC400/300 which were totaled at the junk yard. Please let me know what your thoughts are.

Thank you!

BrittonJ85

Lol I tried as you said and gas started pouring out.

Yeah I learned the hard way and had to place the cover back on and then drain out the gas to about half a tank and then was ok to change the fuel pump.

BrittonJ85

Thanks for the heads up. I ended up buying a real one from a local import shop. It worked and fit perfectly!

BrittonJ85

Thanks for the response. I will try that this weekend. Also I was wondering if you had similar issues as I am and if this corrected your issue? I do remember that with my LS 400 it would stall if I gave it gas and sometimes would not start at all. But I can't understand why the next day after using my SC 400 it would work. It's just too weird. Could the cam sensor cause this interference?

1jzchris

my bad i did say i change min on HALF not FULL............so its my mistake.

BrittonJ85

Not a problem lol.