1993 4runner Fuel delivery issues/no start condition

I have a 1993 Toyota 4unner. 3.0 with 5speed 4x4

So I parked my 4runner for about 2 weeks in order to do some body work. After finishing all that, I tried to start it with no luck. The car cranks but will not start. It would jump to life if I sprayed starter fluid so I started investigating what would cause lack of fuel.

I Jumped Fp to +B and heard nothing. So I replaced the fuel pump. Car worked as soon as I replaced the fuel pump. Also, I did not have any engine codes. The next day I went to start the car and again no start,it acted exactly the same as before.

I rechecked Fp to +B and pump failed to make any noise. I pulled it out and tested the pump directly and it did not run so I returned it to the store for a new one.

I installed the second new Fuel pump (both also got a new strainer) and the car started right away. I drove it around the neighborhood for ~20 minutes then parked it. The next day I tried to start it and nothing. Same exact problem as last time. jumping Fp to +B got nothing.

(I noticed when I pulled the both fuel pumps there was a little bit of fluid around the connection to the fuel pump. Is there a possibility that fuel is sloshing into the plug and shorting it?)


Anyway, I figured there's no way that I got two bad fuel pumps and checked relays. COR was bad and I replaced it. I checked all the fuses and relays. I also went ahead and replaced the EFI relay. Everything else is good/ in spec.

What is the next most likely point of failure? What obvious thing(s) have I missed?

I have done no engine work to this car. I parked it for about two weeks to do some body work and that is it.

 

These things can be annoying I just redid a good used tank the old one was rotten and gummy inside as it sat for 12 years. I ordered a new fuel pump holder once I had it all wired up and tried to put it in the thing was the exact opposite of what I needed. Rather than take a chance on a repeat mistake from the supplier I took my old mount and sandblasted it, the thing looked brand new. Put it all together, cleaned up the sending unit, my problem was getting the gas intake hoses back on, had to cut the hose protector holding the assembly to the frame. It was a lot of work but once the gas was in fired right up, have not driven it around yet, hope I don’t have your problem. This thing has made me tear my hair out over the years, it has a lot in common with my Shovelhead Harley, good luck!

 

Just a thought, I put a new fuel filter in also, have you?

 

Yes, I replaced the filter. But, I tried two new fuel pumps and had the same results with both: worked for a day and then the next day it would not start/ no fuel pressure.

 

Could be a leak in the system somewhere, perhaps air getting in, I noticed the hose that came with the fuel pump was inferior and had a small split where it was forced over the flange. I bought a quality fuel line at the local jobber, no comparison to the cheap Chinese hose that comes with the pump. It should be something simple, just have to find it, check all the connections.

 

Did you get the second replacement pump where you got the first? If so, I would order one from TOYOTA or DENSO and retry. Entire batches of parts may be bad and you could get 5 from that same store which come from the same lot and they may all be made wrong.

If it were me, I'd disassemble the replacement and see why it's not working. If the wires to the pump were shorted to it, that wouldn't fail the pump...it should just burn a fuse. If the pump was made wrong or voltages hooked up wrong, it may burn out.

After you turn off the key, you need to check to make sure that voltage isn't still going to the pump. The pump may have been running all that time while the car is sitting and not flowing fuel and burn out.