Just recently replaced my 1992 sc400 fuel pump and the car started up on the first try, however the fuel gauge did not work. It has been 4 months since and I have put less than 100 miles on the car. I did notice that the fuel pump was not the exact one that I took off. This morning the car would not start I changed the electronic box on the passenger side of the car, no luck. I did the by pass, no luck. Check my codes and I am getting 13 RPM signal, 21 main 02 and heater signal, and 78 fuel pump control. Did I not only get the wrong pump but a failing one? Help any suggestion will be appreciated.

 

What was the part number on the pump you put in? Secondly, the float is prolly sticking. Very known issue. Mine is doing the same thing. To be honest, I don't even think there is a DIY for this issue. Seems to be straight forward but a DIY would be very beneficial. Again my tank stays on full, most of the time and I just reset the trip meter. Sorry i couldnt help much more.

 

Just pulled fuel pump and it had a 1 inch black box that had a number 90980-04082 25010.47:c: other than that there was nothing else readable. The end of the pump had a box type wired screener intaking the gas. When I removed the pump there was gas on the out going end and the box type screener was also full at the incomming fuel. I think I am going to buy another pump. My old pump had a flat bag type strainer.

 

I would like to thank 1992Lexus for his help in getting my car started. He did a whole lot more than just the instructions given below.

OK man, well great... Glad I could help you out.. Here goes. Go by a 30 or 40 amp relay, 4 pin. Wire this this way.... you need to buy also a few spools of wire. One roll of 14 gauge, maybe 30 feet, should be plenty. One roll of 8 or 10 gauge wire, with a inline fuse holder, which will hold a 30 amp inline barrel or blade fuse. your choice on fuse.

Now once you have the wire, inline fuse holder, 30 amp relay and fuse, and the time... Lets run the wire.. From the battery, disconnect the negative and lay aside. Run the 8/10 gauge wire from the battery with a good solid terminal about 6-8 inches long, then place the inline fuse holder. Do not put in yet. Continue to run the wire through the car, through the firewall, beside your seat on the driver side, remove the back seat, if not already. Lay aside. Push the front seat all the way back, and find a fuse that turns on while on the key in the on position. Once found, the top/back fuse near the firewall is one. I believe a 7.5 amp??? Run a wire on one side of the blade fuse in kick panel, again only one side.... Run this wire to the back seat also, leave plenty of slack. Almost done... Now since you have the main power ran, and the remote trigger wire ran, mount the relay on the housing or round plate on the tank, as shown...



just undo the 8mm bolt and put the relay and mount it back and secure.. DO NOT OVER TIGHTEN THE BOLT... JUST SNUG, will strip out...

the main power from battery will go on the far right side. The trigger wire will go in the top, then the bottom is the ground. Secure this to the bolt for the rear seat belt, make sure to scrap the paint if you mount it somewhere else. SCRAPE THE PAINT TO BARE METAL.... The left side goes to the blue wire on the pump. Once these are secured with these crimps shown in the picture, then put in your fuse by battery, connect battery, and then turn the key on, and make sure it turns on and stays while the car is on the ON position ONLY. If not you did something wrong. If it works on and off, then secure all the wires, and put everything back. If you have ANY questions, call me at 205-482-5533. Its late right now, and you are an hour ahead. Mark

Good luck and it is straight forward...

 

Your welcome man. I am glad we got you going. I know the feeling when you get so frustrated on something and you seem so close. Everyone needs help from time to time. I am glad I could help you out... LMK how it is going in a week or two...