95 fuel delivery problems

[sloop]

95 4 door xlt 6 cyl ohv - build date 3/95 - vin number has an x in it - 157,000ish miles

when starting, the fuel pump does not turn on - this has only happened 3 times, the last time it would not start for a few days - seems to drive ok when it does start - each time this has happened, it was weeks/months apart - when it happens, there is no fuel pump relay switch click (and of course, the pump does not prime like it usually does)

i have the ford cd and done lots of reading here - tried a few things to isolate the problem

i checked the fuel pump fuse (it was good) and replaced the fuel pump relay - no change (no fuel pump priming) - i also checked the inertia cutoff - it was not tripped

read how to pull the codes using the cel light on here - did the koeo test

first code group

335 - pfe or dpfe sensor voltage out of self-test range

second code group (cm?)

172 - o2 indicates system lean left
176 - o2 indicates system lean right

while at the parts store, got new plugs, wires, air filter, seafoam, pcv valve, fuel filter, antifreeze, radiator flush, electrical contact cleaner and lucas fuel treatment

checked the fuse again - it started

seafoam through the pcv hose - little smoke
put in new air filter, pcv valve, plugs and plug wires, flushed ratiator, added some fuel treatment - noticed a broken belt tensioner so i replaced that assembly and put on a new belt

bought a fuel pressure tester - tested the pressure at the schrader valve

key on engine off at about 32 psi
key on engine running at about 24 psi

when i turn off the engine, the pressure bounces back up to 30-32 and settles at 24 - the pressure holds with the engine off

i don't have a multimeter and not sure how to use one if i did - but i will buy one if i need electrical measurements

i don't have jack stands or vacuum tester

called a garage chain here in the dallas area and asked for a ballpark figure on a fuel pump replacement - $750

fuel pressure seems low to me - i think spec is 30-45 psi - but the pressure holds after shutoff so the hoses must be solid

since it has only happened 3 times, seems like it must be electrical - and maybe a second problem of low pressure (one guy on here said the minimum pressure to stay running is about 25 psi)

a mechanic said the 172 and 176 cm codes might be related to the low pressure (running lean)

since i have had the ford, the cel light comes on ONLY on long road trips when using the cruise control - i suspect the 172 and 176 codes were stored when that happened - the cel light comes on after about 2 hours on the road - after the car rests, the cel light does not come back on until the next road trip using the cruise control

not excited about confessing this part but it is part of the vehicle history - i changed the radio to be powered on the accessory delay (probably not related) - i also installed the automatic mirror - one of the wires i tapped into was near the kick panel (i can't recall what it was or if it was fuel pump related - i think it was the backup lamp wire) - i used those 3m wire connectors that pierce the wire insulation and requires no splicing (which made me a little uneasy but i thought 'what the hey')

today i disconnected the negative battery terminal for about an hour to reset the computer - i drove it a FEW miles and retested - the koeo test passed (both with 111) and attempted the koer test (the instructions are fuzzy about the brake boo switch, turn the wheel, transmission o/d switch stuff - then wot for the goose test) but i tried it twice

3 flashes for 6 cyls

116 - ect out of self test range 0.3 to 3.7 volts (might not be warm enough?)
326 - pfe or dpfe circuit voltage lower than expected with zero evr duty cycle
538 - insufficient rpm change during koer dynamic response test/ operator error (did not do the wot right i guess so no goose test)
632 - overdrive cancel switch not changing state (e4od) (found i have to press it twice)

i will try the koer tests again tomorrow - i think i found the instructions

from my reading, the fuel pressure regulator is seldom faulted in fuel delivery problems - but i wonder if it could be causing my low pressure reading - i will check the vacuum line tomorrow for gas (that part is only $100 and i can install it - lol)

could it be the computer (pcm or something like that)?

would a pressure reading with the pressure regulator vacuum tube removed be helpful?

i'm thinking i will need to know the voltage and resistence readings - would that help me isolate the problem?

the mechanic told me if the problem happened again, to bang on the fuel tank with a hammer - to see if that causes it to start

would i be better off taking it to a ford dealership and letting them take a stab at it? i am thinking $750 for a fuel pump replacement at a garage is on the high side - i am tempted to try it myself for that kinda money

that is all the info i can think of - any theories, observations or best guesses?

 

[MrShorty]

bought a fuel pressure tester - tested the pressure at the schrader valve

key on engine off at about 32 psi
key on engine running at about 24 psi

when i turn off the engine, the pressure bounces back up to 30-32 and settles at 24 - the pressure holds with the engine off

Assuming the gauge is accurate, the fuel pressure does seem too low, and low fuel pressure would explain the lean codes. So, it seems to me the best place to start is determining why fuel pressure is too low.

Chiltons had a nice fuel delivery diagnostic chart. I don't know if they got it from Ford/Helm or made it themselves (it always looked like something that would come out of a good manuel, though). If you can readily find it, it would give you a nice structure to diagnose this.

Off the top of my head, causes for low pressure:

1) Weak fuel pump
2) Poor electrical connections in fuel pump circuit
3) clogged filter (might just change it if it hasn't been changed in a while. this has happened to mine)
4) kink/clog elsewhere in supply line
5) bad regulator (opening too soon): is fuel being returned to the tank/getting past the regulator into the return line?

 

[sloop]

thanks for the reply

since the pressure is low and the fuel pump won't run sometimes, i think i will replace it next - the pressure reculator would not cause the pump not to run - and from what i have read, it is seldom the cause of problems

from what i have read, there are many types of those pumps - i will replace the entire assembly - i called ford and the part is $260 - they want another $350 to install it - i might try it myself

 

[sloop]

decided to try to replace the fuel pump myself - got the fuel pump - got wheel chocks, floor jack and jack stands

got the bolts loosened, backend up on jack stands and the rear tire off - but i don't know how to remove the two hoses from the filler pipe to the tank the ford cd calls the connection a horseshoe clip - but i don't see how they disconnect

took a picture and uploaded it to photobucket - can someone point me in the right direction?

http://i607.photobucket.com/albums/tt157/original_sloop/ford/IMAGE_057.jpg

 

[sloop]

ok - jumped the gun - i see you squeeze two pieces of plactic inward and pull off the hose

 

[jlsparky7]

Glad your taking the time to work on it yourself and do all the diagnostic work as well.

Im betting on a weak fuel pump as the prob.

 

[sloop]

well that was an adventure - my first time - someone that does not even change his own oil - so for other novices that might be debating replacing their fuel pump, it can be done - and i did it solo

the ford dealership said about $650, a garage (that is a chain here in the dallas area) said $750

my advice and what i learned

read and read more - there are several good how-to threads here - this one closely matched my vehicle

http://www.explorerforum.com/Singleton/web/pages/fuelpump2.html

the ford cd was helpful but not 100% accurate - you can get them on e/bay for $1

the pictures of the fuel pump might confuse you (i replaced the entire assembly) - from my understanding, there are 4 types

2 door explorers made in mexico
4 door explorers made in mexico
2 door explorers made in canada or the usa
4 door explorers made in canada or the usa

your vin number will tell you where your explorer was made - search for 'ford vin decoder' and you will find several sites that tell you what each number or letter in the vin code means

i ordered the fuel pump that rockauto.com recommended - it was about $169 - the motorcraft was $208 (as best i recall)

i bought a floor jack and jack stands from northern tool - from reading here, it seems 3 ton was enough to safely lift and support the explorer - mine is a torin suv model that is rated at about 20 inches but the jack is relatively low enough so it can be used on a car - the jacks and stand packaged together was $89.99 - northern also has a cheap creeper for $22.99 that worked good enough for me - chocks were $9.99 each at northern

ford says don't jack up the explorer using the differential - some do and i was tempted...

you only need 3 metric sockets for the entire job - i did not need a knuckle (universal joint) but did need a short extension

the 2 wheel drive explorers don't have a skid plate under the fuel tank

on my 4 door 95 xlt (2 wheel drive soccer mom version), there are only 3 bolts that hold the tank on - 2 in the front and one for the strap

when replacing the tank, be sure that the strap (on the far end from the bolt) is hooked into its slot - if its not, you will have to drop the tank again

the underside of my ford was surprisingly clean (or i thought so - but i don't think its ever been off road) - but the 2 front bolts were a somba to get loose - i put pb blaster on both the top and bottom a few times and let it soak - i still had to put a pipe on the ratchet handle for leverage

i loosened all 3 bolts before lifting it - and the lugs on the driver side rear tire too

someone suggests that you not remove the 2 front bolts, but to remove the entire support bracket instead (4 bolts hold the support bracket on and the 2 bolts attach to it) - that seems like a tough way to go - the guy said that he was gonna remove the 2 bolts, but one broke - i looked at removing the entire bracket, but the top bolts were too close to the bottom of the floor to access without a metric wrench

there are 3 wires that attach to the inside of the fuel assembly - two are permanently attached and the third has a spade connector - this was not plugged in on the new fuel pump - it was plugged in on the pump i took out so i plugged it in on the new one - might want to check that

externally, there is one electrical connection - fairly straightforward there - its attached to the frame of the ford

the fuel filler connection is two hoses - i removed the connection at the tank to avoid removing the entire filler pipe - there are two opposing plastic things that you squeeze together and pull the hose off - you will know when the plastic things are squeezed enough to remove the hose - i removed these before removing the tank support

there is a similarly connected hose that attaches to the top of the tank - this is not attached to the fuel pump but it must be removed before you can take the tank off - i had to drop the tank a few inches to disconnect this hose, but the hose is short so don't drop the tank too low

the fuel pump has two hoses connected - these are connected the same way your fuel filter is connected - you need that 'special tool' to take off these hoses - you must remove the spring clip that bridges the connector, then insert the tool onto the pipe coming from the pump - i had to lower the tank a couple more inches to access these hoses

now here is something i did not read here - but these two connections are not the same size - i have the metal 'special tool' that works fine on the smaller tube, but had to go buy the plastic 'special tool' to get the larger one off

if you are like me, you think that 'empty the tank completely' thing does not apply to you - it does - i had about 1/4 tank - you can get the tank off, but will have to empty it before you put it back on

i was reluctant to tackle this myself mostly for one reason - crap in the tank - the pros check the inside of the tank when they remove it - there is a reason the fuel pump must be replaced - sometimes its crap in the tank - i checked mine as best i could and it seemed clear - the sock filter looked clean too - do not let your pump replacement be what introduces crap into your clean tank (i read one thread that was about 12 pages long - the guy had replaced the fuel pump 3 times - he took it to a garage and his tank had crap in it)

i think the pros recomment that you replace your fuel filter when you replace the pump - i replaced mine about a week ago

i did not lubricate the gasket with silicone - someone recommended it but i read that silicone eats o2 sensors - some silicone says its sensor safe

have a can of gas ready to refuel after you are finished - i did not reuse the fuel i removed from the tank - paranoia of crap getting in the tank

i had to put some gas in the tank before it would start - but it did start - and while it might be my imagination, it seemed to perform better - my guess is the low fuel pressure (24 psi) was causing it to run sluggish - i will test the fuel pressure tomorrow and post it - i think i will bust the old pump open and see what it looks like (i thought all these small electric motors had done away with carbon brushes a couple of decades ago)

(and thanks for the videos sparky - i should have waited one more day for that fuel filter video - you posted it the day after i replaced mine)

 

[sloop]

another good thread - two people posted their methods in it

http://explorerforum.com/forums/showthread.php?t=187484

 

[jlsparky7]

I'm glad everything went so smoothly for you. Maybe some of my other vids will help you or others later on.

Sounds like you learned a lot. Fuel pump replacement isn't easy for most people. Now you can try tackling some harder projects and save yourself a boatload of cash.

This site owns face.

 

[sloop]

took another pressure reading - up from 24 before i replaced the pump to 30 after - i might replace the fuel pressure regulator - see if that will bring it up to 35 - if i am reading the specs on the ford cd correctly, 35-45 is normal

the location is no party - jambed up under the upper radiator hose and the intersection of lots of wires - guess i should check the vacuum line for fuel first

 

[sloop]

i replaced the fuel pressure regulator - but after filling the tank i noticed the fuel level drop fast - so i raised the backend and checked the hose connections - there are 2 hoses for the fuel filler hose - the smaller one was not seated correctly

seems there are tons of threads on the iac valve - the ford cd says mine is not cleanable but lots of people do - i replaced mine - removed the battery connection to reset the computer

checked the fuel pressure - stays constant at about 28-30 psi - not sure why - the pressure holds after i turn off the engine - have not driven it much but it seems to run good - i think i will leave it as is until after the computer adjusts itself - then poke around checking the vacuum pressure