possible fuel pump issue

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napalm204

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RV Forum to the rescue:

Just put in a new chassis battery and now the engine turns over, but seems like I am not getting fuel.  I checked all the fuses and relay and they are OK.  Could I have somehow messed up my fuel pump connection with how I reconnected my battery?  I have three wires all connected to the red positive post and they are separated with a washer.  Then I have at least three small automotive black wires that bundle in with my big negative cable.  I seem to remember that the fuel pump is powered from the negative post? 

It was all working OK until I put in the new battery.  Now it seems like it is not getting fuel.  The fuel pump is about 3-years old.  I am stumped.

Any suggestions?   
 
The negative post (-) is exactly that, a negative ground. It will not "power" anything. All power comes from the positive post (+). I doubt that there is a single wire to only power the fuel pump, but check that you have not neglected to connect another wire or that in the process of removing the battery you dislodged a connection.
 
It's a Ford.  Does it have one of those fuel pump safety shutoff relays?  I just noticed on my '00 Bounder the sticker that says there's a relay with a reset button somewhere.  Maybe you tripped it in the process of changing out the battery.
 
Wally-  There is indeed a relay switch mounted in the engine compartment fuse box.  I am not familiar with a safety shutoff relay although there may be such an animal somewhere.  I will continue searching, but I am beginning to fear my fuel pump has failed.  All comments are appreciated and I will look at the problem again.
 
I am not familiar with a safety shutoff relay although there may be such an animal somewhere.
Click to expand...

The Ford owner's manual should describe it and its location. Basically it's there to shut off fuel in case of a collision, supposedly triggered by g-loading. I had that happen once (on a car),  perhaps from a strong bump because there was no collision, and the reset was difficult to find, but (in the car) it was under the passenger's side of the instrument panel, near the door.
 
Ya my Dad's tripped that breaker and it took him forever, and a tow truck driver to find it behind the passenger seat in his Tioga Class C.
 
First off...do you have gas in tank? Simple question, but I have seen vehicles brought in on wrecker, with an empty tank. How did you check the fuses and relay? The best way is with a test light or multimeter and probe fuses while key is on. For the relay, switch it out with a known good relay (sometimes other relays in the fuse/relay box can be switched. Don't use one that supplies power to ECM or other critical parts) Assuming your engine is fuel injected (individual injectors or throttle body) there will probably be a pressure port in the fuel line somewhere on or near the injector fuel rail. Looks like a Schrader valve on a tire. Hook a fuel pressure gauge here and check for correct pressure with key on and also while cranking. Look up specs online, if necessary. If no pressure or low pressure check for sounds of the pump running in the fuel tank with key on and then with engine cranking. If engine does not start within 10-15 seconds or less, the pump will shut off for safety. If you hear pump run but no/low pressure, disconnect fuel line from in line filter, both sides, if  equipped ( some filters are in the tank and not serviceable). If filter is clogged or restricted, replace it. If pump doesn't run, check the wiring harness for voltage at pump, if you can reach it, otherwise, try somewhere in the harness running to it. (Assuming fuses and relay were good). If fuses, relay, power to pump, and filter are good, chances are good that pump is faulty.
 
OK boys, motorhome started this morning as if nothing was wrong.  I was amazed.  It started just like it always has.  I tried it again 15-minutes later and it started again.  Then I went for a doctor appointment, came home 2-hours later to try it again and it would not start.  Starter engages but it seems to me that a fuel problem is my culprit.  I am not a mechanic, but the fact that it will start and then fails 2-hours later sounds like a fuel pump.  Can I get an "amen" from anyone? 
 
Sounds like a fuel pump problem, but I would still run some diagnosis on it before settling on that. Replacing an in tank pump is not a 30 min job and can be an expensive mistake if you are wrong. At the least, check fuel pressure. Also replace the fuel filter, which is probably mounted on the left side frame rail. That's relatively simple and cheap and may solve your problem. It may, however, require some specialized tools to release the fuel lines from the filter, which should be available at the parts store and not expensive. Good luck.
 
Well, you've certainly eliminated the crash shutoff. Intermittent like that, and especially if it ran well when it ran, it could as easily be an intermittent electrical connection, or a dirty fuel filter as it could a flaky fuel pump.
 
  Doesn't sound like a fuel pump to me but, you'll know when you check the fuel pressure. You can check the fuel pressure with a tire gauge on the schrader valve located on fuel rail. Make sure the gauge is depressing the valve core stem. May have to remove valve core. ( depress core stem before removing to release any pressure.  If valve core doesn't want to come out easily, use correct fuel pressure gauge) Hold tire gauge on valve and cycle key a couple of times five seconds or so apart. Looking for 30-45 psi. I wouldn't recommend running the engine if valve core is removed.
  I would lean towards a ignition problem. Easy enough to check for spark.  If no spark and No cel, distributor probably ok. Tfi modules can do funny things and won't set cel.  Easy to check. Locate two wire jumper plug tied into wires right by your diagnostic link plug. (Google timing the EEC-IV Ford. This jumper is removed when timing engine) the jumper is usually gray plastic. Remove jumper, if engine starts tfi module is bad. Also, in your bcc the should be an ignition relay. I've seen these cause intermittent problems. There should be other similar relays right next to the ignition relay. Just swap to check. Bet it's something simple. Good luck.
 
You guys are going to love this quick and dirty test for the fuel pump.

Next time it fails to start, get a rubber mallet and the wife.  Have her sit in the driver's seat and attempt to start the coach.  While she's cranking the engine, you crawl under the back of the coach and wail away on the bottom of the gas tank with the rubber mallet.
Sometimes, if the pump is going bad, the vibration you set up in the tank with the mallet will cause the pump to start working.  If the coach starts using this method, you'll be pretty sure it's the pump and your wife will think you're a genius.
 
An even simpler test: Remove the fuel filler cap and have someone listen closely at the filler neck. When the ignition key is turned (do not try to start), they should be able to hear the fuel pump run for a few seconds and then shut off. if that happens, then the fuel pump is operating normally. The problem sounds more like an intermittent connection to me.

Oh, and the collision cut-off switch on the '95 F53 is located near the base of the steering column just above the floor. 
 
I had fuel pump issues on 2000 Tropical rv. PCM relay tested okay but if you tapped on it it would stop working. Beware just because it bench tests okay does not mean it is good.
 
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