1997 Ford 460 ignition

[MrWizard]

since last week, ive been experiencing engine 'run while driving' problems

it starts great, then will NOT accelerate properly, or hesitates, bogs etc..

it started right after i filled the gas at my regular stop

after (2) days of this i added a can of sea foam

and things started improving over the course of several days

this morning it was 'slow' again, i went to gas up and filled up with premium , NOW its back firing and acting even worse

the questions i have are multiple

1997 bounder F53 chassis, 460 CuIn
where are the fuel filters, i can't find them

where are the ICM and EEC MODULES located i can't find them either
all the chassis manual says i have them

i'm thinking filters first and electronic modules 'next'
might be a good idea to get them and have them on hand
even IF not needed at this time

Onan generator is running fine, so i really don't think its a continuing fuel issue, although there could be contamination in the bottom of the tank, below the genny pickup, which has clogged the drive engine fuel filters
i was leaning heavy toward fuel issue until the backfiring started

part numbers and locations needed
and advice
thank you

[theoldwizard1]

MrWizard wrote:
NO schrader bleeder on top of my engine

It has to be there somewhere ! That is where the pressure gauge connects.

When you open the connection did pressurized fuel come out ? If not, your pressure check valve may be leaking. This will cause long cranks, but typically not your symptoms.

[MrWizard]

Filter changed, fg872 $15
Tool kit $10

NO schrader bleeder on top of my engine

*!#=/+ clamp in bracket with steel tube line in front of it

Pain in the A*!#

Will update on drive ability aka engine run on street

[theoldwizard1]

Big Katuna wrote:
A Ford mechanic told me that once the fuel PSI drops below ok level, the ECM goes whacky.

The ECM (EEC-IV) does not go "whacky". As RLS7201 stated, the ECM ASSUME the pressure is correct and injects the amount of fuel require based on that assumption !

[MrWizard]

I saw a video on the filter change
On his there was Schrader valve above the engine to release pressure on the fuel system before he went under the RV too remove the filter
Also saw the plastic tool kit for releasing the couplings
Going to parts store to get filter and tool kit

[Big_Katuna]

Sounds like pump to me; mine had the same symptoms. If I flipped the ignition off then on and restarted it would run ok for another X minutes.

A Ford mechanic told me that once the fuel PSI drops below ok level, the ECM goes whacky. I thought my ECM was bad. Backfiring, missing, idled ok, give it accelerator.

You can put a psi meter on the fuel rail and monitor it.

I had so many bad experiences trying to get mine fixed while on vacation in the NE, I limped home and found a good shade tree guy that had a F53.

I didn’t have to drain the tank. He said run it down to 1/8 tank. He undid the rear strap and loosened the fronts which gave him access to the top.

There is an adapter harness reqd too.

There was a thread here years ago from a guy that added a elec fuel pump near the filter leaving the OEM in place. The mod (Bounder something?) had it..
Dirt Dog?

Good luck.

Any brake dragging problems?

[MrWizard]

Thanks will look for the filter and the modules
I will not attempt the fuel pump myself
No way am I pumping out gas and dropping the tank
That will have to go to a shop, hope it does not come to that

[RLS7201]

Fuel filter is on the left frame rail, about mid ship. You can buy the clip release tools at any parts store. The set is cheap. I have no corrosion problems with the clips on my 95 F53. The problem starting after fueling would indicate fuel filter. If the filter don't correct the problem, you need to run a fuel pressure test while driving. About 32 lbs of pressure at idle and about 38 lbs at wide open throttle. Fuel pressures are important. The ECM is dependent on designed pressures for proper air fuel ratios. Your fuel pump is of turbine design and does not get noisy when failing. Just running the test while sitting still will not prove or disprove the fuel pump.
I suggest OEM motorcraft replacement fuel pump, if needed. That way you change the sending unit too.
Rockauto/Motocraft fuel pump.
Thin film ignition (TFI) is on the left, outside firewall, under master cylinder, on heat sink. If you elect to replace the TFI, make sure to get the gray one. The black TFI won't work on you MH. Your EEC-IV is in front of the steering column, next to floor. There is a 4 digit "catch code" on the ECM. You will need that code if you elect to look for a replacement. For example, 95 catch code looks like this "MOOØ".

Richard

[theoldwizard1]

The fuel filer should be mounted somewhere along the side rail. You need a special tool to replace it. WARNING ! At that age, the connectors MAY be corroded beyond use. If so, new connectors will need to be spliced in. Use a Motorcraft replacement filter (likely a Motorcraft FG872 - less than $10).

The fuel pump is IN THE TANK. Before replacing do 2 simple tests. First, crawl under the back so that your heard is near the fuel tank. Have some one switch the ignition from OFF to ON (not START). Bad fuel pumps are very noisy.

Rent a fuel pressure tester and check the fuel pressure. Specific number are not as important as the pressure staying consistent at idle and at high idle (about 2000 RPM).

If you do decide it is the fuel pump, the job is not too bad as long as the tanks is EMPTY. Yes, you have to drop the tank ! I recommend Bosch, Denso or Delphi (Delco) fuel pumps. Sometimes you can buy just the fuel pump, but most times it is the complete assembly: pump, pickup, sock and fuel level sender. For the extra $50-$100, probably worth it.

[MrWizard]

Pump...
Ok before I crawl nose to tail 36ft under this thing
Where is this pump located ?
Rear near the gas tank, or hiding up front

Ken ...Delco what.... Filter or pump?

[kenwautoone]

Pump

[kenwautoone]

Ford's 460 , chronic fuel pump issues.when you change it out ,be sure to use ac Delco or motorcraft fuel ....Ken

[Nick-B]

Change the fuel filter then check your fuel pressure. Sounds like a typical failing fuel pump. Low pressure will also cause backfiring.

[ArchHoagland]

My gas tank holds 75 gallons so once a year I add five cans of Seafoam before a long trip. Each can treats about 15 gallons of gas. I run my Onan generator at least an hour while the Seafoam is in there.

When was the last time you replaced plugs and wires?

At night can you see any cross firing between spark plug wires?

[Heisenberg]

My 1996 Dolphin 460 did the same thing. It ended up being the fuel pump. The rail pressure was low. The problem being intermittent made it more difficult to find. The fuel filter is on the drivers frame rail inside in front of the tires. You need a Ford fuel line doohickey to change it out and watch for the gasoline squirt it seemed to have a check valve. It has been a while.............