efi, fuel pump help

[allard6]

replaced fuel pump last fall with an oem toyota pump with a new strainer, worked great all winter now blows fuse and shuts down on thermal protection (happened 5 days ago and today). if i let it site (tow it home) it starts up and runs fine. i let it run in the driveway tonight for about 45 min then it blew the fuse and went out again. any ideas why this is happening, i ordered new strainer, fuel filter, and fuel press. reg. if this doesnt work i guess another filter. has this happened to anyone else? thanks

 

[jonheld]

Vehicle specifications please.
How do you know "shuts down on thermal protection"? What diagnosis did you use to determine this?
What fuse is it blowing?

Without the most basic information it is impossible to help.

 

[80t0ylc]

How much fuel is in your tank? IIRC, the 80 Series Toyota fuel pumps are designed to be immersed in fuel to help keep them from over-heating. One of the main reasons not to run your tank out of gas.

 

[allard6]

sorry for the limited info, it is a 93 fj80 4.5 w just homemade headers and exhaust, k@n filter tires lockers etc. when it dies it blows the efi fuse that shuts down power the 12v supply to the fuel pump harness. when it happened monday i removed the assembly to inspect the strainer and bench test the pump. by the time i removed it must have cooled down because it worked great, i reinstalled and it started right drove all week then all of a sudden it did it again i check the efi fuse and it had again blew. i replace and it blew right away. got it home with friends trailer replaced the fuse and it started up again. i let it run this time in the drive way and check different amp draws on the efi harness everything seemed fine but after about40 min of idle it tripped and blew the fuse i have to wait about 4hrs before it will let me replace the fuse without trippin. and if it helps both times i had almost a full tank. thanks for the help. you can email me at josh_allard@yahoo.com or just reply to post.

 

[SUMMIT CRUISERS]

Check wires and connections associated with the fuel pump and relay. Could be a fuel pump ground or a wire that would be discolored caused by wire corrosion, heat or restriction (kinked). Wiring gremlins can be hard to find, but look close at all the associated wires and connections. You mentioned new homemade headers and exhaust. ?Could this be heating up a relay or wiring harness? Lastly, might change out the fuel pump. I chased a similar problem on my 92. After driving about an hour my truck would start learching/hesitating. I did the EFI wiring upgrade and relocate to inside cab. I think this is specific on the 91's and 92's. Changed filters multiple times. Changed the Fuel Pressure Regulator. All of which did not fix the problem. Changing the 3 or 4 year old fuel pump and strainer fixed the problem. Now mine's good. I hope this helps and a bump for you.