just picked up a 89/90 ford f150 xlt , the issue is the truck will only start on starting fluid then shuts off , there is NO fuel @ the rail , engine is 302 efi ,

fuel pump makes noise and the rear pump has been changed , i thought it was the tank selector vale , but to no avail can i find the Fking thing anywhere , ive followed all the fuel lines , they go from the fuel rails then to the tanks with no valve , im at a lose , i know 100% its a fuel issue , picking up a relay now but isnt there supposed to be a FTSV?

 

ok, so there is absolutely no valve, no place where one is missing , just 2 tanks 2 fuel pumps some lines and a filter, i hot wired my rear fuel pump and it is definitely coming on and running , but no fuel is coming out of any line anywhere

 

Have you changed the filter?
Could be blocked up.
If the fuel isnt coming out of any line, drop the tank to see if rust is blocking up the strainer.

 

yeah fuel filter is new and supposedly the rear tank pump was just changed , it looks new compared to the environment around it , , i have the EFI there seems to be a set up that dosent have a tank selector valve only a switch on the dash if im understanding correctly , pretty sure thats the one i have im totally stumped , i just bought the truck last night i knew it had a fuel issue , but i didnt think it would be this hard to figure out , and from my understanding hotwiring my pump should shoot fuel out correct ?

 

It should shoot out fuel, if it's hotwired.
I had issue when I got my truck that it would run fine when it was sitting still, but once you got moving, sloshing the fuel around in the tank (as well as the rust), the rust would get stuck against the strainer and the truck would "run out of fuel".

Worth a shot.

 

by chance could it be the actual sending unit and not the pump if thats how these systems work (idk?)

 

There's three pumps in a dual tank system. One in each tank (on the sending units) and one on the frame rail.

 

if he's a 90, he has 2 in tank pumps only. if hes an 89, he has a frame pump also. unclear what year his truck is...


find the fuel pump test port on the drivers side fender well, near the air filter. you can find it from searching on here....or google...ground that out and it will help you diagnose. you have a fuel pump relay, the switch, and the two pumps. find the test port, run the fuel pump(s), listen and/or bust out the voltmeter. all of the above are easily tested...if they are all good then you have a bad circuit or failed computer.

 

I agree....1990 was the first year for the in-tank high pressure fuel pump setup which eliminated the frame rail pump. It makes a HUGE difference to know what model year truck the OP has.

 

It says 90 on title but chassis sticker says 89 , its the efi with only two pumps

 

You have a 1990 made in late 1989.
No you do not have the valve on the frame or the pump on the frame.
If the rear pump does pump and you have nor fuel at the engine you may have a bad FPM (pump) in the front tank and all the fuel is going to the front tank.

 

Ok i have the rear tank lines un hooked at the pump , when i kick it with a hotwire no fuel , but pump is deff making noise , it does seem that the frint tank is the problem , without going and sourcing a bunch of parts am i able to bypass the front tank ? With some extra fuel line ? Just got the relay gonna check that now

 

Update for today , changed fp relay , nothing new , gonna start testimg componets today, short of a wiring issue ,the only things that are left are , ecm , switch and pumps correct ?

 

If the pump runs the the fuse link, fuel pump relay, selector switch and the ecm (PCM Computer) are OK.

 

OP...heed what is said above...all of your diagnostics support this suggestion. the fact that it makes noise and doesn't pump indicates that its getting voltage, but not working.


you can ground out the fuel pump test terminal with front tank selected and see if you hear the same faint noise from it, thatll confirm that the voltage is being sent through its proper channels.


then/or just replace the pump.