Hi,
I am new to the Ford big blocks and trying to troubleshoot and old motorhome I bought.
It's a 1987 ford 460 from and E350 chassis.
Moto was running fine and steady.
Before a huge trip I wanted to clean things up so I cleaned the carb with sea foam and put carb cleaner in the fuel tank.
I drove for about 3 hours with no issue and parked the motorhome in the driveway, nose up on a very slight slope (4-5 degrees)

After 2 weeks, I tried starting the motor and had a very very hard time starting it. After 10 minutes or so, I finally go it running. but it died after 30-40 seconds.
I can start it back with pedal pumping, but it always dies out. A lot quicker if I give it gas.

I thought it was a fuel problem because of the carb cleaner in the tank so I replaced the fuel filter to no avail.

Still the same behavior :-(
I am a bit desperate as I'm to leave on my trip in 8 days.

Thanks in advance for all your help

Phil :-(

 

It *could* be a fuel problem because of debris dislodged by your 1-2 punch of carb + fuel treatment.

Try starting it on ether.
Will it catch right away?

It could be an issue with the fuel pump.
I'm not entirely sure if these motor home chassis have the same "Hot Fuel Handling" system as the pickups did.
I know they used the same Holley for Motorcraft 4180 carburetor.

If it is a hot fuel handling system, then you need to check that oil pressure cutout switch is activating the fuel pump relay.
This idea fits your symptoms of priming while cranking but dying in 30 seconds.

Ask 'Subford' in the '87-'96 forum.
He is very good with motor home electrical diagnosis.

Good luck, Phil!

 

1. Does anyone have the parts number for the 1986 E350 oil pressure switch that keeps the fuel pump running??