I have a 1988 toyota truck 4x4 3.0 and ive checked everything wires fuses relays ect and i cant get the fuel pump to turn on. The truck just turns over i thought it would be in the computer because there seems to be corrosin around the walls aof the computer base, How is a way to turn my fuel pump on (maybe from the dignosis line using a paper clip? any help needed thankyou.

 

Welcome to YT. Why waste time trying to turn it on with a paper clip? Clean ALL your contacts first. If still no luck, replace the pump.

 

It might not be a bad pump maybe the wiring was damaged somewhere between the ecm and the pump and the pump just never gets the signal or maybe it's a relay. swapping parts gets pricey quick find out why it's not working first.

 

Well you see i have change the fuel pump and tested the other one beacause the new one didn't work and the old one works fine. I have looked at the relays and fuses. I have found that there appears to be water damage in the computer when testing it with a test light. The funny thing is i had the gas line un hooked and touched the tes light up to 2 contacts and the pump turned on, But when i tried it the next day the pump did not turn on. So please tell me what that could be. I need help, thankyou

 

im in the same boat only i have a 1989

 

If you have water damage to the computer, replace it. If there was water there, the your COR mounted above it is probably shot as well. The COR controls the fuel pump operation. Do you hear it clicking when cycling the ignition?
Use the link in my signature to open the online FSM, and test the COR as well as the computer.

 

Make it easy on yourself; use the "Special Service Tool" (paperclip) to jump FP and B+ on the diagnostic connector. Do you hear the pump start? Can you now start the truck? If so, your problem is on the COR, VAFM, ignition switch side. If not, your problem is on the fuel pump (and wiring) side.

 

all of a sudden the self diagnostic box isnt working im getting voltage to the fuse box and no i dont here anything click and whats driving me nuts if i put a test light on the efi relay i get no voltage but i put a testlight on the fuel pump and show voltage

 

when it did work it read code 43 heres what started it it blew the efi 15 amp fuse i used a jumper wire to get home as i pulled in the drive it died again and this time the jumper wire didnt work and i havnt ben able to start it since

 

It is time to break out the multimeter and start testing continuity for your EFI circuit wiring. You have a short somewhere, and with what you mentioned about the water leak on the computer, I would start in that area looking for trouble. Start from where the EFI fuse is located, and check continuity on all wires related. Use the FSM wiring diagrams to help.
http://www.ncttora.com/FSM/1990-1995...emci/eng3r.pdf

 

i dont have water damage and i think ive tried everything as well i notice when i put a testlight on things and they dont lite up ill put my test light on the positive termainal on my battery and they light up that seems very odd to me or when i put a jumper wire from my horn fuse to the efi fuse the efi relay and everything put the fule pump comes on and i cant find a bad wire is there a way to test just the computer to see if its bad and mine is a 1989 i think its differant than the 88

 

id love to use my diagnostic conecter but it dosent seem to be working either

 

If by your "diagnostic connector" you are referring to a paper clip (or something similar) then jump TE1 to E1 and turn the ignition to acc on. If you are referring to a ODBII diagnostic connector, this will not work. The systems area ODB1 on this truck.
Do you have a multi meter? If so, you need to open the FSM, and start doing the diagnostic testing to check the computer and the wiring coming into the computer. When you start to discover a problem, then trace that problem wiring, etc. There is no quick fix for wiring problems, just have to get to it.