• Subscribe to a Magazine
Item Posts    Sort Order

Fuel pump won't work

 
jeff69
New User
Posts: 16
Joined: 06/13
Posted: 08/18/13 11:03 AM

Funny thing, I went out today and put in my old computer for fun.  And when I put the old one in the pump wouldn't run at all, Then I installed the used one that I bought last week and the pump runs all the time. Hmmm.  I seen on the net last week that A sure sign that a puter is bad is when the pump runs all the time.  So now I don't no if my old puter is bad or not..Frown  not happy.  I will check the grounds like you suggest and let you no what I find.  Tks..  

Post Reply
waynep712222
User
Posts: 124
Joined: 03/13
Posted: 08/18/13 11:58 AM

i am totally hoping that you are connecting and disconnecting the computers with the battery disconnected..

please... also check the 10 pin disconnects on the top of the motor next to the plenum.

sometimes the pins get loose.. the sleeve pins need to be tightened...

from a C to a O so they grab the pins tight...  

Post Reply
jeff69
New User
Posts: 16
Joined: 06/13
Posted: 08/19/13 09:29 AM

GOOD NEWS !!!  It runs.Smile  But it runs rough, I checked the fuel pressure and only getting 15-20 psi.  Now would this be the computer( not right for car) or is it the fuel pump?  I left it run about 20min and it still runs the same. Thought puter needed to learn.  But no better.  Too get it to run I cleaned the ground to batt terminal and another to the inner fender.  Tried my old puter and won't run.  Guess I have to figure what is wrong now.   But your help was great....  Thanks.  

Post Reply
waynep712222
User
Posts: 124
Joined: 03/13
Posted: 08/19/13 10:57 AM

15 to 20 psi.. is just barely enough to keep the engine running...


does the pressure increase or change when you pull the vacuum hose off the fuel pressure regulator on the intake.???

can you find the fuel pump relay...

run a voltage drop test..  from the positive battery to the wire that goes to the fuel pump out of the relay???

you could have a wiring issue still.. you will also need to find the inertia switch..

with the engine running.. PROBE both wires with the volt meter..  one test lead into one.. other test lead into the other.. you should get almost 0.00 volts.   if you get more than that...

JUMP the wiring at the inertia switch.. see if the pump pressure comes up...

inertia switches have failed before.. burning and reducing current to the pump..

i wonder where the fuel pump is grounded at????  

the fuel pump COULD BE BAD..

the fuel filter CLOGGED..

not enough electrical connection to the fuel pump power side..
starting at the solenoid, fusible link. relay pigtail. relay, pigtail again. inertia switch fuel pump connector.

not enough electrical connection to the fuel pump Negative side... starting at the small wire from the battery negative to the body.. from the body to where the fuel pump grounds to the body at.. either under the back of the car or thru the fuel tank sending unit assembly..

in looking at the fuel pump sender with the intank pump.. seems there are only 2 wires that plug into it.. one for the electric fuel pump .. one for the gauge..

please.. get under the car and hook up to the fuel tank..  and the body... make sure that at 20 volts.. with the car running.. that you show 0.00 on the volt meter..

try again at the battery negative post to the body.. 0.02 volts MAX at the front..

if you get more.. you could be having an issue..

if you want, and your volt meter has a 15 or 20 AMP DC scale.. you can locate the power wire to the fuel pump... please have the ECM disconnected... power up the pump directly at the fuel pump relay socket..   you should have right around 7.1 amps..


you are getting CLOSER...  

Post Reply
waynep712222
User
Posts: 124
Joined: 03/13
Posted: 08/19/13 11:01 AM

oh... fuel pumps fail..

they wear out.. they are brush type motors that are not only submerged in gasoline.. they have gasoline running thru the inside of the pump.. cooling it..

the brushes wear..   the commutator wears... the bushings wear.. the pump cavity wears..

blocked or clogged fuel filters will overheat the pump cause failure..

kinked fuel lines.. will overheat the pump and cause failures.

running the car or truck almost out of gas will allow the pump to spin at excessive speeds and ruin the pump.. bushings and brushes..

water in the fuel tank.. rust in the fuel tank.. will get into the fuel pump and either rust it up.. or wedge the magnets to the rotor with rust..


holes in the fuel pump filter pickup screen  will cause the pump to fail within 30 minutes ..


an important test... when you turn off the pump.. does the pressure hold??? or does it drop to ZERO almost instantly.. that might indicate the fuel pump hose might be bad. inside the fuel pump...
please do not pinch off the fuel lines.. they are plastic and will be ruined.. there are plugs available for testing..  

Post Reply
waynep712222
User
Posts: 124
Joined: 03/13
Posted: 08/20/13 07:40 AM

you will want to spend the time and print the info out on this page.


its well done and should really help you.

http://oldfuelinjection.com/?p=6


it has more info than i had.  

Post Reply
jeff69
New User
Posts: 16
Joined: 06/13
Posted: 10/29/13 11:59 AM

Hey Wyane, thanks for the site.Looks good.  Just wanted to let you no that I bought a new fuel pump today and got it on.  I turned the key and cranked it and no go, But I jumped the fp relay and listened and I could hear squirting or what sounded like air in the rail.  I cranked it again and still no go, I then poured some gas into the throttle body and cranked it and it took off and ran(pretty rough).  I thought it would only burn the fuel I poured in it, but it kept running.  This is what happened the last time I got it to run, but only if I put fuel in the TB.  While I had it running I checked the FP and it was running 35 psi.  So the new pump fixed that but it won't start on it's own after a day or so without priming it.

 Could this be the regulator or something else?  And maybe the puter isn't right for it, I'm flustered and it's costing me more $$$ and not fixing the problem.
I seem to think that the reg is stuck open and allowing the fuel to run back to the tank more then what should.  But then I also have 35psi now to the rail.  Any thoughts would be great.  Thanks.  Jeff.  

Post Reply
jeff69
New User
Posts: 16
Joined: 06/13
Posted: 10/29/13 12:00 PM

Hey Wyane, thanks for the site.Looks good.  Just wanted to let you no that I bought a new fuel pump today and got it on.  I turned the key and cranked it and no go, But I jumped the fp relay and listened and I could hear squirting or what sounded like air in the rail.  I cranked it again and still no go, I then poured some gas into the throttle body and cranked it and it took off and ran(pretty rough).  I thought it would only burn the fuel I poured in it, but it kept running.  This is what happened the last time I got it to run, but only if I put fuel in the TB.  While I had it running I checked the FP and it was running 35 psi.  So the new pump fixed that but it won't start on it's own after a day or so without priming it.

 Could this be the regulator or something else?  And maybe the puter isn't right for it, I'm flustered and it's costing me more $$$ and not fixing the problem.
I seem to think that the reg is stuck open and allowing the fuel to run back to the tank more then what should.  But then I also have 35psi now to the rail.  Any thoughts would be great.  Thanks.  Jeff.  

Post Reply
wayne712222
User
Posts: 65
Joined: 10/13
Posted: 10/29/13 06:06 PM

engine off.. fuel pump wiring jumped and the pump running.. should be 39 PSI..

throw a coolant temp sensor at this also...  i know.. its another 15 bucks...

unless you can get it running and run the KOEO and KOER test..

let me go back and reread above.. its been a while..

and did you put a NEW FUEL FILTER in when you changed the pump...

and did you use a new strainer on the end of the pump...

how is the ground connection at the fuel tank??


and.. YES.. fuel pressure regulators have failed before.. usually not in that way.. but anything is possible..  

Post Reply
wayne712222
User
Posts: 65
Joined: 10/13
Posted: 10/29/13 07:11 PM

clean these...  on the core support. and there are some on the inner fenders...

Fordcoresupportgrounds Zps48c74c23


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

fix anything that looks like this...

Fordbatterytobodygroundwire Zps74c67080


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


clean the connections with all the wires on them...

and i know that yours is a flat type of solenoid..

Ford Starterrelay Zps688e3fbd


Ford Starter Solenoid Flat

this is for a different ford..


EECIV Fuelpumprelaydiagnostic Zps67d80b9d




270 Eec Fuel Pumprelayconnector Zps5cdcc7b3  

Post Reply
wayne712222
User
Posts: 65
Joined: 10/13
Posted: 10/29/13 07:45 PM

on the green connector for the fuel pump relay...

check for power on PIN 5... with the relay removed...

with a short section of wire with male quick connects  you might even put a toggle switch in this jumper.. so you can manually control the fuel pump. ON and OFF..

pin 5 to Pin 3 should turn on the fuel pump.. key off or key on.. the fuel pump should run..  

please..  use a digital volt meter from  the Positive battery post to the back side of PIN 5... you should have 0.04 or less volts...

WHAT do you get.. this is from the Battery POST.. not the cable.. not the solenoid..

if you get more than 0.04 volts.. you have a dirty connection between the battery cable and the relay socket...  

Post Reply
wayne712222
User
Posts: 65
Joined: 10/13
Posted: 10/30/13 08:52 AM

say... also...  find your inertia switch.. somewhere in the back of the car...

when you have the engine running..    and you have checked the voltage at the front as described above...


please.. check the voltage between BOTH wires on the inertia switch one at a time, to ground..

engine running..

so the upper wire to ground  is...___________

the lower wire to ground is.. ___________

the upper wire to the lower wire is..__________




the insides of inertia switches look like this...

Inertia Switch


these  can burn the contacts inside.. and reduce the current to the fuel pump and cause low fuel pressure issues..

if you get any measurable voltage when the volt meter is set to 20 volts DC and you are measuring the upper wire to the lower wire...

also.. please check for cuts in the wire.. i have chased dead fuel pumps to find people have chopped the wiring at the inertia switch and twisted it loosely together. then call me and ask why their car won't start..  

Post Reply