I'm trying to fix this RV for a friend. They claim they were using the generator, and ran the tank dry, and after putting more fuel in it, the fuel pump was dead.

The truck is a single tank model, with a pump in tank, and a booster pump on the framerail. I was told the pump was somewhat new, so I didn't think to bench test it right away. (First thing I'm doing when I go over there again.)

I plugged my scanner in and got an array of codes:

14 - Profile Ignition Pickup Circuit Failure
41 - System Indicates Lean
53 - Throttle Position Sensor Circuit Above Maximum Voltage
87 - Primary Fuel Pump Circuit Failure
96 - Fuel Pump Circuit Open-Battery To PCM

From there I decided to focus on the fuel pump, and traced the circuit from beginning to end, and could not find a fault. The inertia switch was good, the fuel pump relay was good, the wire from the relay to the pump was good, the EEC relay was good, and the wires from the PCM to both the battery, fuel pump relay and EEC relay were all good.

I'm starting to suspect either a bad ground, a bad PCM, or the possibility that I overlooked something and I'm just chasing my tail...

Any input would be appreciated.

 

Hi FordGuy, welcome to FTE! It would be helpful if you could post some more information about the RV. Which year, configuration, and engine would help us give you a hand on this one.

 

I'm unsure of which engine it is, its a gasoline V8, thats all I know.

Its a 1989 E350 chassis, RWD, Single tank, Fleetwood RV. I really dont know too much about it, its a friends vehicle, not my own...

 

This not possible.
The fuel pick-up for the generator designed to lose suction at 1/4 tank of fuel to let you get some place to get more fuel.


That said if the fuel hose between the tank fuel pump and tube in the tank going out of the tank to the engine has disintegrated the generator could have used fuel below this bad hose. Then the high pressure pump on the frame would not be able to suck fuel from the tank. Photo below of bad hose.


It is hard to guess what these code mean as you did not tell us if they are KOEO, CM or KOER codes.


That said "14 - Profile Ignition Pickup Circuit Failure" most of the time means you have a bad PIP sensor.
The 41 could be a lot of things from EGR stuck open, vacuum leak, bad fuel pump or a bad FPR.
The 53 most of the time is bad wiring (ground).
87 most of the time is a bad fuel pump.
96 most of the time is a bad fuel pump relay, fuse link or wiring under the fuel pump socket.


Also check the small black ground wire with a green stripe coming off the NEG post of the battery.


Look close for the bad hose in this photo:


/

 

Sorry, should've specified, the truck does not run. Will start with a little starting fluid. Without the starting fluid, it just cranks. No fuel at all. I checked the relay, fuseable link, and fuel pump wiring, all good. Also, the black with green tracer wire was also good.

 

Then ground pin #6 of the self-test connector, turn on the key and see if the fuel pumps run and it will start.



/

 

From what you are saying you now have no fuel at the engine. You friend may have run it totally dry by driving, if so, get into the tank to check the pump.

When you turn the ignition key to on, but not starting, you should hear the fuel pump running for a few seconds. If it is not running, you need to look deeper into the codes.

If it is running the fuel pump hose may have popped of. This happened to me after the clamp loosened off after many years of use.

You have some work to do and I hope your buddy fills the fridge with beer for helping you out.

 

my rv will not stay running, F350 equiline RV 1989...

how do we figure out where the problem lies... thanx, new at this.. d

 

Your going to haft to help us out a little to find out what is wrong.
I take you have read the posts in this thread already.

How long does it run before it dies?
When it dies will it start right back up or do you half to wait a while.
If it does not start right back up can you hear the frame fuel pump run for one second each time you turn on the key?
Dose this RV have a Fuel Injected engine?

 

runs a few min max with push of gas pedal and spudders out. restarts next time but same deal.. not sure about fuel injection is that in owners manual? not sure about third question.. my buddy got underneath after we read these posts to see whats where.. found one fuel pump middle of vehicle sorta, we dont know if there is another in fuel tank or not
what we wonder is how to figure out whats wrong without buying a bunch o new parts we may not need

 

Diana,

Ok with the fuel pump on the frame it is fuel injected and you do also have on in the tank.

I will take it then you have one fuel tank.

From what you say I will also take it that it will start right back up.

So it seems the fuel system is working OK at this point and you are losing spark or the exhaust is plugged.

Do you have anyway to test for spark and do you have a test light.

Does your buddy or you have any tools and able to work on the RV's engine?

 

ok, is the one in the tank easy to get at or not? yes one fuel tank n generator hooks up to that somehow.. is the test light a like the battery tester...? how do you check for spark? yes he has tools. works on RV many times... he did spark plugs a few summers back.. we did change the fuel filter already... sure didnt hurt, lol.

 

Hi Diana,
Have your buddy hook up a fuel pressure tester.
https://picasaweb.google.com/jimandn...14344249763650

My '88 E150 had low fuel pressure, wouldn't run much faster than a walk before quitting.

Good luck
jim

 

No, you have to drop the fuel tank and if it is full it is very heavy and you need a floor jack or draning it first.

Their is a extra fuel tap on top of the fuel pump hanger for the tank that the generators fuel pump hooks to.

No, see photo below.



One type of spark tester is in the photo below. It is the one I use.
You ground it to a good ground (Block) and put a spark plug wire or the coil wire hooked to the tester, adjust the tester and crank the engine and watch for spark to jump the gap.


You can also stick a screw driver in the wire and hold the shaft near a ground and watch for spark.

If it is not starting some just spray carb cleaner in the intake to see if the engine will try to start but this does not apply in your case.

In your case I would put a fuel pressure test on the fuel rail and start the engine and see if the fuel pressure drops down to kill the engine.
Normal fuel pressures are 30-34psi at idle and around 40psi at WOT.
You can also check the fuel pressure with the engine not running by grounding pin #6 of the self-test plug. See diagram earlier in this thread.
You can rent a fuel pressure tester at most auto part stores and get all your money back when you take it back.
/

 

thanx bob, will show all this to my buddy n see what we can do... really appreciate your time.. gonna rain here all weekend so will prolly resume next week... thanx again.. d