SuprRunner

Has anyone here actually replaced thier fuel pump before? I did a search and found nothing.

I was looking for help last night while changin mine, and let me say "WHAT A PITA!!!!!"

My arm is all cut up from having to do this. The fuel pump on on the back side of the fuel pump...the part you can't get to. You can't pull out the fuel tank because all the lines are back behind and under the tank where you can't get to. I had to undo the filler and the fuel sending cap, unbolt the fuel tank, and pry it away from the back seat bulkhead as far as I could get it, and wedge a 3" pipe behind there. Then I had to feel around where th cover is, undo all the little 8mm bolts, pull the cover off, and look through the fuel guage sending unit hole to undo the 3 10mm bolts that hold on the bracket, then undo a hose that is inside the gas tank by reaching my hand in through the back hole while looking in through the front. Then pulling the pump off the hardline without cutting off your arm in the processes is another. Once you get all that done, pulling out the fuel pump wasn't soo hard. ARGGGG!!!

Word of advice, put a towel over the top of the gas tank...IT IS SHARP!!!!

I will post a couple pics a little later.

johnee78

iTrader: (4)

This could of been alot easier if you would removed the backseat and then unbolted the plate that would give you access to the front of the gas tank where the fuel pump is located.

SuprRunner

You have to look through this hole(too small to fit hand)



to see this.

As you can see, there are 3 10mm bolts(circled in red) and a hose clamp that has to be removed in order to pull the bracket out.

SuprRunner

Sorry, no plate there, have you ever looked? Mine is a 1993...maybe they made a access panel on newer GS's, but not mine.

johnee78

iTrader: (4)

I think maybe you should look..Remove your back seat and the padding thats behind it.You will see a black plate that is held on with 10mm bolts(I think).Remove this plate and the pump is right there..the picture you posted is the the tank seen from the trunk..Also I have had my 93 gs300 for 5 yrs..

SuprRunner

Maybe I am just un-lucky. There is no plate. I checked. I would have to remove the entire rear cover which is bolted and glued in.

johnee78

iTrader: (4)

Which cover are you referring to ??

Epik

iTrader: (7)

yrea, the black plate is the one he is talking about.. it is bolted and glued on. real PITA to get it off with the glue, but once you do the access for the fuel pump is right there... lifts right out.

now is the time for me to ask the question.. did you get it installed? did it work? are you using a TT pump or a 255? I couldnt get any power to my 255 when i installed it. i have heard about a fuel pump ecu possibly?? it is in the trunk, up behind the edge above the power antenna. i did what a friend of mine told me to (he has done several Aristo swaps) and it didnt work even then. I had to mess with a few wires in the Diagnostic connector under the hood to get power to the fuel pump.

SuprRunner

This cover is what seperates the trunk from the cab. It is almost as big as the back seat itself.

I don't believe my car has a fuel pump ECU. I looked for it, but it is not where it should be according to a 1995 GS300 electrical manual.

I dropped in the Walboro 255L pump. Works great. noisy though.

Epik

iTrader: (7)

yup, that is the cover i'm talking about.. 3ft or so across..

when i put in my pump there was no power to it. took the stock pump and plugged it in and it worked perfectly.. plugged the 255 in and nada again.

the only way i could get it to function was to go into the diagnostic connector under the hood and jumper the 2 pins for the "fuel pump test". only thing is, now the pump runs from the minute you turn the key.. no prime and shut off if you dont start the car.

oh yea, i cut the wires to those 2 pins further down in the harness and joined them thru a 30 amp inline fuse for safety.

if the thing in the trunk is not a fuel pump ecu..then what is it?? it is small.. about 3" by 2".. has a plug with i think 5 wires in it.. has a heatsink.. almost looks like a resistor box... i dont have a lexus FSM.

hopefully the gte ecu will solve any of those problems and i wont need this jumper/fuse junk anymore.

SuprRunner

I would prefer not to break that seal between the trunk and the front area. I was able to do it this way, even though it was a pain.

That is wierd that you pump wouldn't work. Maybe you do have a fuel pump ECU and if you did the 12v mod that would have taken care of the problem, because the 12V mod bypasses the ECU all together.

The 1995 GS300 says it is near the Antenna. I do have a plug there where it might have been, but it just plugs right back into another plug and back into the harness. I will have to do some more searching though...just to make sure. I will check with a friend of mine who works at toyota. He can look at the 93GS300 diagrams for me.

I wonder what the stock psi was, because even at 20psi I can't run my fuel map for my MAP-ECU, it starts running way way rich. Still, I tried the Powerhouse 440cc map and it is way way rich at idle, but extreamly lean as soon as I hit boost, so lean, it goes off the charts. Guess I am going to have to create a new map.

Epik

iTrader: (7)

yea, if you can have your friend check it out for me that would be awesome. my stock pump was crap..as many are after almost 240k miles..LOL

i had to completely retune the car after installing the 255 of course.. looking forward to the next dyno session though..dialing in the "twins"

SuprRunner

I was probably lucky to get 10psi out of my old pump. Like yours, 235,000 miles on the thing. Probably why I couln't get fuel past 6psi boost, no matter how rich I tried to make it. With my new pump, it won't go less than 20psi and I run major rich with my current map.

Epik

iTrader: (7)

you are running the MAP ecu right? Not familiar with that software.. but is it windows based? I mean cant you just click and drag to change a whole range of fuel? Try starting out with 5% decreased fuel across the low range for idle and drivability. My experience with standalones is with AEM and K Pro.. not sure how MAP software is set up to work.

SuprRunner

It is somewhat point and click. You can change each individual cell, or adjust a row or colum by a percentage. Really slick and easy to tune. Not quite as easy as an SAFC, but a lot more function.

I wish they would to a linux based version, as I like it much better than winbloz