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Ron
Ron, RV Mechanic
Category: RV
Satisfied Customers: 35023
Experience:  32 years Master Tech ASE certified.
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I have a 97 f53 with a 460. I just replaced the fuel pump

Customer Question

I have a 97 f53 with a 460. I just replaced the fuel pump and cleaned out the tank. With new gas and fuel pressure regulator valve and new filter. It ran great for 1 mile and falls on its face when I push on the gas. Need help please. John
Submitted: 11 months ago.
Category: RV
Expert:  Roy Belding replied 11 months ago.

good afternoon my name is ***** ***** I will assist

from your description, it sounds like the dirt and debris from the tank was still in the lines and injectors. you may need to replace the injectors. there is no additive that will rid the injectors of the debris.

Roy

Customer: replied 11 months ago.
Thanks for the answer Roy the truck idles so smooth you cannot say glass of water ripple on the dash it just stumbles under acceleration as it is starving for fuel
Expert:  Roy Belding replied 11 months ago.

yep, it may enough fuel for idle but beyond that they cannot meet the needs of the amount of fuel required

Roy

Expert:  Roy Belding replied 11 months ago.

please dont forget to rate me as it is the only way I get paid for my efforts

Roy

Expert:  Roy Belding replied 11 months ago.

please dont forget to rate me as it is the only way I get paid for my efforts

Roy

Customer: replied 11 months ago.
I have $800 worth injectors will be here in the morning take me about an hour to put them in and we'll see what happens I'll get back to you tomorrow
Expert:  Roy Belding replied 11 months ago.

ok

Customer: replied 11 months ago.
Just installed 8 injectors still doing the same thing. Any other suggestions?
Expert:  Roy Belding replied 11 months ago.

not without being there and looking at it myself. I will opt out and re list for you

Roy

Expert:  Ron replied 11 months ago.

Hello different Expert here,

Before you replace any more parts, can you connect a fuel pressure gauge to the service port and monitor the actual fuel pressure while the problem is occurring and post back with the results?

Customer: replied 11 months ago.
34 psi at startup up to 40 when I first accelerate and then under hard acceleration down to 10 with the occasional backfire
Customer: replied 11 months ago.
today I put in a new Ford fuel pump also
Expert:  Ron replied 11 months ago.

Okay there is nothing thats going to cause the pressure to drop providing the fuel filter is clear then a defective fuel pump. The backfire is caused by the drop in pressure, was the fuel filter rechecked?

Expert:  Ron replied 11 months ago.

Was the pick up screen on the the old pump clear?

Customer: replied 11 months ago.
Just put on another new one today also
Expert:  Ron replied 11 months ago.

Was the fuel filter clear?

Expert:  Ron replied 11 months ago.

There is nothing that going to cause this kind of pressure drop beside a failed pump or a restriction in the system.

Customer: replied 11 months ago.
Not to bad I did pump out all the old Fuel and clean out the tank it is spotless on the inside now and it wasn't too bad to begin with
Expert:  Ron replied 11 months ago.

Okay well if you are sure you have a clean tank and a clean filter as well as a good working pump and no restriction in the line then the pressure should not drop under load. Have you checked to see if by chance someone may have added another filter?

Customer: replied 11 months ago.
Just the 1 filter
Expert:  Ron replied 11 months ago.

Okay well if you are sure there are no restrictions and the tank is venting and your new pump is okay then the pressure should hold to at least 32 PSI and the engine should not fall on it face.

Customer: replied 11 months ago.
I agree but there's gotta be something causing it I'm going to go check a few things thanks for your help I'll get back to you in a little bit
Expert:  Ron replied 11 months ago.

Just for the hell of it, leave the gas cap off and see if the pressure still drops.

Expert:  Ron replied 11 months ago.

That will tell you if your dealing with a venting issue.

Customer: replied 11 months ago.
Ok thanks I will give it a try
Expert:  Ron replied 11 months ago.

Your very welcome and thank you as well. Im here if you need me.

Customer: replied 11 months ago.
I just checked the entire fuel line every inch of it that is one fuel filter which I just replaced again with an extra one I had there's no damage the fuel line and it still doing the same exact thing
Customer: replied 11 months ago.
I have been broke down in this parking lot 6 days and I've spent about $1,300 is there anything else you can think of that might help
Expert:  Ron replied 11 months ago.

Providing there are no restrictions in the fuel system and its venting properly and your new fuel pump is not defective then the only other thing I can think of would be to check the running voltage at the fuel pump to make sure you have battery voltage at the pump as well as a good ground.