'89 BII with 2 fuel pumps?

[97fordrunner]

Hey guys, yet another issue with my '89. It won't fire at all, I got spark, and fuel. last time it did run it ran ok to start with then after a little while of driving it started to hesitate upon application of throttle. At first it was at almost 3/4 throttle then it started doing it at lower amounts and then it finally died at a light and wouldn't restart at all. I had a prior code saying it was the MAP sensor and tonight I swapped in a new one and not go. Is it possible that it threw the timing off enough that I have to re-set it? As for the 2 pumps the truck has a factory pump in the tank as well as one on the frame rail where a filter usually is and there is no filter.


Help please its drivin me crazy

 

[97fordrunner]

Update....

I re-checked fuel and I found I have none at the rail. I can hear the relay clicking on the pass. fender. Also found codes 86, 89 and 95. The first two are for the A4LD that is no longer in the truck and the last is a fuel pump code. Any clues or known bad spots in the harness?

 

[short bus]

run a hot jumper wire to the fuel pump on the frame to see if it works at all.To check the one in the tank remove the cap put a hose down in the neck till it stops put it to your ear and have someone turn on the key the fuel filter is on the drivers side on the frame between the pump and eng. dumb place for it just did that to both of mine one was bad pump and the other was blown fuse

 

[adsm08]

I agree with short bus. mine did the same thing and it turned out to be my HP fuel pump. easy enough fix, and a lot cheaper than the boost pump.

 

[97fordrunner]

But being that its an '89 it shouldn't have two pumps correct?

 

[short bus]

I dont know when they changed but the 89 I scraped was a early 89 and it had two but it could have been altered from the prev. owner he was kinda strange and I did find some things on that rig that sould not have been on it.

 

[97fordrunner]

Did it have a in-line fuel filter or any filter at all? Mine might be that same situation

 

[alaskan155]

my 89 didn"t have a fuel pump on the rail, just a high pressure in the tank and a filter behind the RABS on the frame rail, if you have a battery, spare time and some spare wire try sending power to the pumps and see if they even turn on, just a + and - connection,

thought 88 was the last year for dual pumps, and they went to a single pump when they updated the dash

 

[slobby351]

if the bulid date is after 3/89 it does not have fraim rail pump the pump on the fraim rail if it does not run fuel will not get threw the hp pump if the one in the tank runs take the fraim rail pump out and check the fuel pres

 

[97fordrunner]

Ok thanks guys, Hopefully it will quit raining one of these days so I can get under it with power

 

[kunar]

i dont remember for sure but i think you can just ground the fuel pump terminal on the self test connector to test the fuel pump. i dont remember if this bypasses the relay or not, but it is worth looking into.

http://www.therangerstation.com/tech_library/OBD_I.html

 

[97fordrunner]

Right on that is great info thanks kunar

 

[97fordrunner]

Update, Today was nice out so I got under the truck, had 6 volts to the pump on the frame rail I removed the pump and tested with 12 volts and the pump runs, I plugged the relay in and checked voltage at terminals, I only had 12 volts on 3 of the 4 terminals and 6.5 at the terminal orange/green wires that go to the computer and to the inertia switch, I used a jumper wire on the terminals going to the inertia switch and got the pump to run, now with a guage on it and its is only putting out 12-14 PSI. It also runs constantly when doing this I just did it for testing. Furthermore the wiring is hacked to hell and the truck should not have the pump on the rail the wires were for the pump were simply wrapped around the wires going to the tank and had tape wrapping them so yeah its ugly.

Question now is what would cause the 6.5 V on one terminal at the relay? That terminal has two wires one goes to the computer and the 2nd goes to the inertia switch.