im getting a fault code that says the 'Fuel pump secondary circuit fault" code 95 on my code reader.
Truck is a 1988 f350 460 motor EFI 2wd C6 tranny that was completely rebuilt about 200 miles ago. the fuel system was totally replaced- Both tanks, In tank pumps, DFR, inline fuel pump, filter, kirban Adj Regulator w/ gauge.Fuel pump relay and inertia switch. The truck ran great for 200 miles and then when when i was accelerating it just started to lose power ,went about 2 miles and died in the middle of a very busy road here in NJ. Fu------ A i got it towed home and this morning im out there and i have NO fuel pressure. I switch back to all the old parts that i know still work and nothing. I jump the EEC tester between #2 and #6 to turn on the pumps and i only get 18-20 lbs of fuel pressure. When i turn on the key the inline pump runs but not the in tank pumps!!either of them i have 2 Bosch intank pumps that are brand spanking new !!!. Im totally stumped at this point as im not too good with electrical problems on how to solve them. HELP i really want to drive my truck again. Anybody have any ideas how to fix this problem. Truck is my DD!!! i really want to solve this problem myself with you guys help

Thanks Guys

biglar

 

Sounds like you may have a bad selector switch in the dash.

 

its the only thing i havent replaced yet!!

Thanks bill

larry

 

bill the only part # i can find for the selector switch is F2TZ-9A050-a which is for a 1992-1997 f350. Will this work on my 1988 f350? and if not do you have a part # for me??

thanks again

Larry

 

Do not think it will work.
The 92-97 switch is kinda rocker switch built into the dash high by the headlight switch and the ones in the 80's are like a toggle switch mounted low on the dash.

I would test it before replacing it.

 

well this POS still isnt running!!!!! ive replaced the tank selector switch, All relays,pulled the fuel lines from the DFR and fuelfilter -no clogs, changed regulator to a another new adjustable kirban FPR- nothing. All i can get is 20 lbs of fuel pressure when doing the EEC test jump procedure. with the key on no fuel pressure registers at all on the shrader valve gauge.i just cant figure out what is wrong. Im ready to BLOW this F------ ford up. You know with this dual tank system these geniuses came up with its a wonder any of there trucks run. In comparison i also have a 2007 TOYOTA fj cruiser that i changed my sparkplugs at 120,000 miles and brake pads for the first time last week and it runs and ran as good as the day i bought it. No wonder toyota has been Kickin fords *** all over the planet for the last 20 years. well anywho sorry for venting ,just someone please help me with this truck!!! and please before you answer please read the prior posts

BigLar

 

Well the code says their is a voltage problem at the out put of the fuel pump relay.
The computer said it told the relay to make (complete the circuit from the fuse link at the starter relay to the inertia switch) and then it looked for the the right voltage at the output of the relay. The voltage was either lower or higher then normal. This told the computer that a pump or wire was open or the there was to big of a load on the wire (short in a motor wining or a short to ground).
So the compute issued the code 95.

I would say you have a bad pump motor and as it does it on both tanks I would guess that the high pressure pump motor is bad.

 

Hi Bill first off thanks for all your help i really appreiciate it!! I went to advanced Auto last nite and swapped the hi pressure pump and put the new pump in this morning. still no fuel pressure. i did the EEC test from port #2 to port #6 and the hi pressure put turned on and ran but i didnt hear the 2 back tanks kick on and the fuel pressure didnt build this time to 20 lbs ????,so i unplugged the connector to the inline hi pressure pump and redid the test and now i have no intank pumps running from either the front or rear tank? Now im really stumped. What makes the 2 intank fuel pumps turn on and what could this be???. Ive checked all my fuses-swapped out relays-inertia switch-in dash tank selector switch. Please help i just dont know what to do at this point. remember that the truck ran great for 200 miles and all of a sudden i just started losing power and then after about 2 miles of bogging down and bucking and backfiring it just quit. I also swapped out the dizzy and TFI module thinking maybe this was the problem. When the truck just died i didnt have any fuel pressure so something just gave up and for the life of me i just cant figure out what happened

Larry

 

You may have to get a test light (meters do not work well in this circuit) and trace to where you are losing power.
Make sure the small black wire with a green stripe leaving the NEG post of the battery is well grounded to the NEG post.
Make sure the body (not the frame) also has a good ground from the NEG post of the battery to body with a 10 GA wire.
Make sure the fuel pumps ground at the radiator support is OK.

If all of this is OK and you still have problems start at the battery side of the starter relay on the fender and try to pull the fuse links apart by hand. If one of them stretches it is bad.
Then check the wiring under the fuel pump and ECC Power relays. It is a common problem on an 88 to have bad wiring here and you may have to replace the relay sockets.

Then check the big yellow wire at the fuel pump relay for power, it should be hot at all times.
Unplug the high pressure pump on the frame as we do not want it running without cooling fuel going through it.
If all OK above at this point jumper pin #2 to pin #6 of the EEC self-test plug and turn on the key.
Both relays should click to their make (picked) state.
Check for power leaving the fuel pump relay (brown wire).
Next check the power entering and leaving the Inertia switch (brown wire in and pink wire with a black stripe leaving).
If OK go on to the Selector switch and check for power going in the switch and the selected wire leaving the switch (see diagram below for wire colors).
If the power is still OK and the selected pump is not running unplug the plug on top of the tank and see if you have power on the pump power wire.
If not start back tracking towards the firewall (safety wall) plug.
If you have power at the plug then ground your test light with the plug and check for power again at the pump power wire. If the test light lights change the in tank pump.




/

 

bill theres a relay located on the drivers side fender wall and next to the firewall under the hood spring. What does this relay do?? were getting close to solving this problem

Thanks larry

 

If you have a electric fuel tank selector valve it might be the fuel tank selector relay.

 

Not to hijack this thread but I have a similar problem on a '91 F250 460 automatic. Is the '91 similar in that it has pumps in tank and a high pressure pump external?

if so where is the external pump located? Where is the fuel pump relay found?

I also posted similar questions on a separate thread but have gotten no answers as yet.

Thanks

Archie

 

No the 91 is NOT similar.
You do not have an high pressure pump external or a selector valve on the frame.
However the fuel pump relay is in about the same place.

 

There are 2 relays next to each other- next to the air box and the eec test port. I believe one of them is the eec relay the other? ,i dont know and the relay on the fender wall - firewall drivers side ?? Bill i dont have an electric selector valve i have the manual DFR please read the prior posts

larry

 

The other is the fuel pump relay (green bottom). The EEC Power relay has a brown bottom.
My 88 shop manual does not show a relay on the firewall (safety wall). 87 carb 460 with the electric selector valve I think had one in that area, I know the E350 vans did.

I read a lot of Threads on eight web sites so I do not have time to go back and reread each one and sometimes one Thread will blend to another so sorry if you said what valve you have and I missed it.